Copy parser tools packages into this repo
Jack Firth
3 years ago
parent
ab8a7437a9
commit
db7fa0e156
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parser-tools-doc
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Copyright (c) 2010-2014 PLT Design Inc.
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This package is distributed under the GNU Lesser General Public
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License (LGPL). This means that you can link this package into proprietary
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applications, provided you follow the rules stated in the LGPL. You
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can also modify this package; if you distribute a modified version,
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you must distribute it under the terms of the LGPL, which in
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particular means that you must release the source code for the
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modified software. See http://www.gnu.org/copyleft/lesser.html
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for more information.
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#lang info
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(define scribblings '(("br-parser-tools.scrbl" (multi-page) (parsing-library))))
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#lang info
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(define collection 'multi)
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(define deps '("base"))
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(define build-deps '("scheme-lib"
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"racket-doc"
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"syntax-color-doc"
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"br-parser-tools-lib"
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"scribble-lib"))
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(define update-implies '("br-parser-tools-lib"))
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(define pkg-desc "documentation part of \"br-parser-tools\"")
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(define pkg-authors '(mflatt))
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parser-tools-lib
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Copyright (c) 2010-2014 PLT Design Inc.
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This package is distributed under the GNU Lesser General Public
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License (LGPL). This means that you can link this package into proprietary
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applications, provided you follow the rules stated in the LGPL. You
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can also modify this package; if you distribute a modified version,
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you must distribute it under the terms of the LGPL, which in
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particular means that you must release the source code for the
|
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modified software. See http://www.gnu.org/copyleft/lesser.html
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for more information.
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#lang racket/base
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;; This module implements a parser form like the br-parser-tools's
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;; `parser', except that it works on an arbitrary CFG (returning
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;; the first sucecssful parse).
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;; I'm pretty sure that this is an implementation of Earley's
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;; algorithm.
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;; To a first approximation, it's a backtracking parser. Alternative
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;; for a non-terminal are computed in parallel, and multiple attempts
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;; to compute the same result block until the first one completes. If
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;; you get into deadlock, such as when trying to match
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;; <foo> := <foo>
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;; then it means that there's no successful parse, so everything
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;; that's blocked fails.
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;; A cache holds the series of results for a particular non-terminal
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;; at a particular starting location. (A series is used, instead of a
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;; sinlge result, for backtracking.) Otherwise, the parser uses
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;; backtracking search. Backtracking is implemented through explicit
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;; success and failure continuations. Multiple results for a
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;; particular nonterminal and location are kept only when they have
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;; different lengths. (Otherwise, in the spirit of finding one
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;; successful parse, only the first result is kept.)
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;; The br-parser-tools's `parse' is used to transform tokens in the
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;; grammar to tokens specific to this parser. In other words, this
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;; parser uses `parser' so that it doesn't have to know anything about
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;; tokens.
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;;
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(require br-parser-tools/yacc
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br-parser-tools/lex)
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(require (for-syntax racket/base
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syntax/boundmap
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br-parser-tools/private-lex/token-syntax))
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(provide cfg-parser)
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;; A raw token, wrapped so that we can recognize it:
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(define-struct tok (name orig-name val start end))
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;; Represents the thread scheduler:
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(define-struct tasks (active active-back waits multi-waits cache progress?))
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(define-for-syntax make-token-identifier-mapping make-hasheq)
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(define-for-syntax (token-identifier-mapping-get t tok [fail #f])
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(if fail
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(hash-ref t (syntax-e tok) fail)
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(hash-ref t (syntax-e tok))))
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(define-for-syntax (token-identifier-mapping-put! t tok v)
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(hash-set! t (syntax-e tok) v))
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(define-for-syntax (token-identifier-mapping-map t f)
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(hash-map t f))
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;; Used to calculate information on the grammar, such as whether
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;; a particular non-terminal is "simple" instead of recursively defined.
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(define-for-syntax (nt-fixpoint nts proc nt-ids patss)
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(define (ormap-all val f as bs)
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(cond
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[(null? as) val]
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[else (ormap-all (or (f (car as) (car bs)) val)
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f
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(cdr as) (cdr bs))]))
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(let loop ()
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(when (ormap-all #f
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(λ (nt pats)
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(let ([old (bound-identifier-mapping-get nts nt)])
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(let ([new (proc nt pats old)])
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(if (equal? old new)
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#f
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(begin
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(bound-identifier-mapping-put! nts nt new)
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#t)))))
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nt-ids patss)
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(loop))))
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;; Tries parse-a followed by parse-b. If parse-a is not simple,
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;; then after parse-a succeeds once, we parallelize parse-b
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;; and trying a second result for parse-a.
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(define (parse-and simple-a? parse-a parse-b
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stream last-consumed-token depth end success-k fail-k
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max-depth tasks)
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(define ((mk-got-k success-k fail-k) val stream last-consumed-token depth max-depth tasks next1-k)
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(if simple-a?
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(parse-b val stream last-consumed-token depth end
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(mk-got2-k success-k fail-k next1-k)
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(mk-fail2-k success-k fail-k next1-k)
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max-depth tasks)
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(parallel-or
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(λ (success-k fail-k max-depth tasks)
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(parse-b val stream last-consumed-token depth end
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success-k fail-k
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max-depth tasks))
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(λ (success-k fail-k max-depth tasks)
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(next1-k (mk-got-k success-k fail-k)
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fail-k max-depth tasks))
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success-k fail-k max-depth tasks)))
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(define ((mk-got2-k success-k fail-k next1-k) val stream last-consumed-token depth max-depth tasks next-k)
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(success-k val stream last-consumed-token depth max-depth tasks
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(λ (success-k fail-k max-depth tasks)
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(next-k (mk-got2-k success-k fail-k next1-k)
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(mk-fail2-k success-k fail-k next1-k)
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max-depth tasks))))
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(define ((mk-fail2-k success-k fail-k next1-k) max-depth tasks)
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(next1-k (mk-got-k success-k fail-k) fail-k max-depth tasks))
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(parse-a stream last-consumed-token depth end
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(mk-got-k success-k fail-k)
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fail-k
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max-depth tasks))
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;; Parallel or for non-terminal alternatives
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(define (parse-parallel-or parse-a parse-b stream last-consumed-token depth end success-k fail-k max-depth tasks)
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(parallel-or (λ (success-k fail-k max-depth tasks)
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(parse-a stream last-consumed-token depth end success-k fail-k max-depth tasks))
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(λ (success-k fail-k max-depth tasks)
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(parse-b stream last-consumed-token depth end success-k fail-k max-depth tasks))
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success-k fail-k max-depth tasks))
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;; Generic parallel-or
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(define (parallel-or parse-a parse-b success-k fail-k max-depth tasks)
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(define answer-key (gensym))
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(define (gota-k val stream last-consumed-token depth max-depth tasks next-k)
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(report-answer answer-key
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max-depth
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tasks
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(list val stream last-consumed-token depth next-k)))
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(define (faila-k max-depth tasks)
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(report-answer answer-key
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max-depth
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tasks
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null))
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(let* ([tasks (queue-task tasks (λ (max-depth tasks)
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(parse-a gota-k faila-k max-depth tasks)))]
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[tasks (queue-task tasks (λ (max-depth tasks)
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(parse-b gota-k faila-k max-depth tasks)))]
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[queue-next (λ (next-k tasks)
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(queue-task tasks (λ (max-depth tasks)
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(next-k gota-k faila-k max-depth tasks))))])
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(define ((mk-got-one immediate-next? get-nth success-k) val stream last-consumed-token depth max-depth tasks next-k)
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(let ([tasks (if immediate-next?
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(queue-next next-k tasks)
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tasks)])
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(success-k val stream last-consumed-token depth max-depth
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tasks
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(λ (success-k fail-k max-depth tasks)
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(let ([tasks (if immediate-next?
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tasks
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(queue-next next-k tasks))])
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(get-nth max-depth tasks success-k fail-k))))))
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(define (get-first max-depth tasks success-k fail-k)
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(wait-for-answer #f max-depth tasks answer-key
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(mk-got-one #t get-first success-k)
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(λ (max-depth tasks)
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(get-second max-depth tasks success-k fail-k))
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#f))
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(define (get-second max-depth tasks success-k fail-k)
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(wait-for-answer #f max-depth tasks answer-key
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(mk-got-one #f get-second success-k)
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fail-k #f))
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(get-first max-depth tasks success-k fail-k)))
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;; Non-terminal alternatives where the first is "simple" can be done
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;; sequentially, which is simpler
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(define (parse-or parse-a parse-b
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stream last-consumed-token depth end success-k fail-k max-depth tasks)
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(define ((mk-got-k success-k fail-k) val stream last-consumed-token depth max-depth tasks next-k)
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(success-k val stream last-consumed-token depth
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max-depth tasks
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(λ (success-k fail-k max-depth tasks)
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(next-k (mk-got-k success-k fail-k)
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(mk-fail-k success-k fail-k)
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max-depth tasks))))
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(define ((mk-fail-k success-k fail-k) max-depth tasks)
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(parse-b stream last-consumed-token depth end success-k fail-k max-depth tasks))
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(parse-a stream last-consumed-token depth end
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(mk-got-k success-k fail-k)
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(mk-fail-k success-k fail-k)
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max-depth tasks))
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;; Starts a thread
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(define (queue-task tasks t [progress? #t])
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(make-tasks (tasks-active tasks)
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(cons t (tasks-active-back tasks))
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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(or progress? (tasks-progress? tasks))))
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;; Reports an answer to a waiting thread:
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(define (report-answer answer-key max-depth tasks val)
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(define v (hash-ref (tasks-waits tasks) answer-key (λ () #f)))
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(if v
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(let ([tasks (make-tasks (cons (v val) (tasks-active tasks))
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(tasks-active-back tasks)
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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#t)])
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(hash-remove! (tasks-waits tasks) answer-key)
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(swap-task max-depth tasks))
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;; We have an answer ready too fast; wait
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(swap-task max-depth
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(queue-task tasks
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(λ (max-depth tasks)
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(report-answer answer-key max-depth tasks val))
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#f))))
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;; Reports an answer to multiple waiting threads:
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(define (report-answer-all answer-key max-depth tasks val k)
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(define v (hash-ref (tasks-multi-waits tasks) answer-key (λ () null)))
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(hash-remove! (tasks-multi-waits tasks) answer-key)
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(let ([tasks (make-tasks (append (map (λ (a) (a val)) v)
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(tasks-active tasks))
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(tasks-active-back tasks)
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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#t)])
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(k max-depth tasks)))
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;; Waits for an answer; if `multi?' is #f, this is sole waiter, otherwise
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;; there might be many. Use wither #t or #f (and `report-answer' or
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;; `report-answer-all', resptively) consistently for a particular answer key.
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(define (wait-for-answer multi? max-depth tasks answer-key success-k fail-k deadlock-k)
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(let ([wait (λ (val)
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(λ (max-depth tasks)
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(if val
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(if (null? val)
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(fail-k max-depth tasks)
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(let-values ([(val stream last-consumed-token depth next-k) (apply values val)])
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(success-k val stream last-consumed-token depth max-depth tasks next-k)))
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(deadlock-k max-depth tasks))))])
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(if multi?
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(hash-set! (tasks-multi-waits tasks) answer-key
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(cons wait (hash-ref (tasks-multi-waits tasks) answer-key
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(λ () null))))
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(hash-set! (tasks-waits tasks) answer-key wait))
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(let ([tasks (make-tasks (tasks-active tasks)
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(tasks-active-back tasks)
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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#t)])
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(swap-task max-depth tasks))))
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;; Swap thread
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(define (swap-task max-depth tasks)
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;; Swap in first active:
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(if (null? (tasks-active tasks))
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(if (tasks-progress? tasks)
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(swap-task max-depth
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(make-tasks (reverse (tasks-active-back tasks))
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null
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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#f))
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;; No progress, so issue failure for all multi-waits
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(if (zero? (hash-count (tasks-multi-waits tasks)))
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(error 'swap-task "Deadlock")
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(swap-task max-depth
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(make-tasks (apply
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append
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(hash-map (tasks-multi-waits tasks)
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(λ (k l)
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(map (λ (v) (v #f)) l))))
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(tasks-active-back tasks)
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(tasks-waits tasks)
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(make-hasheq)
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(tasks-cache tasks)
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#t))))
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(let ([t (car (tasks-active tasks))]
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[tasks (make-tasks (cdr (tasks-active tasks))
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(tasks-active-back tasks)
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(tasks-waits tasks)
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(tasks-multi-waits tasks)
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(tasks-cache tasks)
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(tasks-progress? tasks))])
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(t max-depth tasks))))
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;; Finds the symbolic representative of a token class
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(define-for-syntax (map-token toks tok)
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(car (token-identifier-mapping-get toks tok)))
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(define no-pos-val (make-position #f #f #f))
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(define-for-syntax no-pos
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(let ([npv ((syntax-local-certifier) #'no-pos-val)])
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(λ (stx) npv)))
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(define-for-syntax ((at-tok-pos sel expr) stx)
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#`(let ([v #,expr]) (if v (#,sel v) no-pos-val)))
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;; Builds a matcher for a particular alternative
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(define-for-syntax (build-match nts toks pat handle $ctx)
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(let loop ([pat pat]
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[pos 1])
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(if (null? pat)
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#`(success-k #,handle stream last-consumed-token depth max-depth tasks
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(λ (success-k fail-k max-depth tasks)
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(fail-k max-depth tasks)))
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(let ([id (datum->syntax (car pat) (string->symbol (format "$~a" pos)))]
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[id-start-pos (datum->syntax (car pat) (string->symbol (format "$~a-start-pos" pos)))]
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[id-end-pos (datum->syntax (car pat) (string->symbol (format "$~a-end-pos" pos)))]
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[n-end-pos (and (null? (cdr pat)) (datum->syntax (car pat) '$n-end-pos))])
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(cond
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[(bound-identifier-mapping-get nts (car pat) (λ () #f))
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;; Match non-termimal
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#`(parse-and
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;; First part is simple? (If so, we don't have to parallelize the `and'.)
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#,(let ([l (bound-identifier-mapping-get nts (car pat) (λ () #f))])
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(or (not l)
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(andmap values (caddr l))))
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#,(car pat)
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(let ([original-stream stream])
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(λ (#,id stream last-consumed-token depth end success-k fail-k max-depth tasks)
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(let-syntax ([#,id-start-pos (at-tok-pos #'(if (eq? original-stream stream)
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tok-end
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tok-start)
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#'(if (eq? original-stream stream)
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last-consumed-token
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(and (pair? original-stream)
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(car original-stream))))]
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[#,id-end-pos (at-tok-pos #'tok-end #'last-consumed-token)]
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#,@(if n-end-pos
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#`([#,n-end-pos (at-tok-pos #'tok-end #'last-consumed-token)])
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null))
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#,(loop (cdr pat) (add1 pos)))))
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stream last-consumed-token depth
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#,(let ([cnt (apply +
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(map (λ (item)
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(cond
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[(bound-identifier-mapping-get nts item (λ () #f))
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=> (λ (l) (car l))]
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[else 1]))
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(cdr pat)))])
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#`(- end #,cnt))
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success-k fail-k max-depth tasks)]
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[else
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;; Match token
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(let ([tok-id (map-token toks (car pat))])
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#`(if (and (pair? stream)
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(eq? '#,tok-id (tok-name (car stream))))
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(let* ([stream-a (car stream)]
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[#,id (tok-val stream-a)]
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[last-consumed-token (car stream)]
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[stream (cdr stream)]
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[depth (add1 depth)])
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(let ([max-depth (max max-depth depth)])
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(let-syntax ([#,id-start-pos (at-tok-pos #'tok-start #'stream-a)]
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[#,id-end-pos (at-tok-pos #'tok-end #'stream-a)]
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#,@(if n-end-pos
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#`([#,n-end-pos (at-tok-pos #'tok-end #'stream-a)])
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null))
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#,(loop (cdr pat) (add1 pos)))))
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(fail-k max-depth tasks)))])))))
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;; Starts parsing to match a non-terminal. There's a minor
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;; optimization that checks for known starting tokens. Otherwise,
|
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;; use the cache, block if someone else is already trying the match,
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;; and cache the result if it's computed.
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;; The cache maps nontermial+startingpos+iteration to a result, where
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;; the iteration is 0 for the first match attempt, 1 for the second,
|
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;; etc.
|
||||
(define (parse-nt/share key min-cnt init-tokens stream last-consumed-token depth end max-depth tasks success-k fail-k k)
|
||||
(if (and (positive? min-cnt)
|
||||
(pair? stream)
|
||||
(not (memq (tok-name (car stream)) init-tokens)))
|
||||
;; No such leading token; give up
|
||||
(fail-k max-depth tasks)
|
||||
;; Run pattern
|
||||
(let loop ([n 0]
|
||||
[success-k success-k]
|
||||
[fail-k fail-k]
|
||||
[max-depth max-depth]
|
||||
[tasks tasks]
|
||||
[k k])
|
||||
(define answer-key (gensym))
|
||||
(define table-key (vector key depth n))
|
||||
(define old-depth depth)
|
||||
(define old-stream stream)
|
||||
#;(printf "Loop ~a\n" table-key)
|
||||
(cond
|
||||
[(hash-ref (tasks-cache tasks) table-key (λ () #f))
|
||||
=> (λ (result)
|
||||
#;(printf "Reuse ~a\n" table-key)
|
||||
(result success-k fail-k max-depth tasks))]
|
||||
[else
|
||||
#;(printf "Try ~a ~a\n" table-key (map tok-name stream))
|
||||
(hash-set! (tasks-cache tasks) table-key
|
||||
(λ (success-k fail-k max-depth tasks)
|
||||
#;(printf "Wait ~a ~a\n" table-key answer-key)
|
||||
(wait-for-answer #t max-depth tasks answer-key success-k fail-k
|
||||
(λ (max-depth tasks)
|
||||
#;(printf "Deadlock ~a ~a\n" table-key answer-key)
|
||||
(fail-k max-depth tasks)))))
|
||||
(let result-loop ([max-depth max-depth][tasks tasks][k k])
|
||||
(define orig-stream stream)
|
||||
(define (new-got-k val stream last-consumed-token depth max-depth tasks next-k)
|
||||
;; Check whether we already have a result that consumed the same amount:
|
||||
(define result-key (vector #f key old-depth depth))
|
||||
(cond
|
||||
[(hash-ref (tasks-cache tasks) result-key (λ () #f))
|
||||
;; Go for the next-result
|
||||
(result-loop max-depth
|
||||
tasks
|
||||
(λ (end max-depth tasks success-k fail-k)
|
||||
(next-k success-k fail-k max-depth tasks)))]
|
||||
[else
|
||||
#;(printf "Success ~a ~a\n" table-key
|
||||
(map tok-name (let loop ([d old-depth][s old-stream])
|
||||
(if (= d depth)
|
||||
null
|
||||
(cons (car s) (loop (add1 d) (cdr s)))))))
|
||||
(let ([next-k (λ (success-k fail-k max-depth tasks)
|
||||
(loop (add1 n)
|
||||
success-k
|
||||
fail-k
|
||||
max-depth
|
||||
tasks
|
||||
(λ (end max-depth tasks success-k fail-k)
|
||||
(next-k success-k fail-k max-depth tasks))))])
|
||||
(hash-set! (tasks-cache tasks) result-key #t)
|
||||
(hash-set! (tasks-cache tasks) table-key
|
||||
(λ (success-k fail-k max-depth tasks)
|
||||
(success-k val stream last-consumed-token depth max-depth tasks next-k)))
|
||||
(report-answer-all answer-key
|
||||
max-depth
|
||||
tasks
|
||||
(list val stream last-consumed-token depth next-k)
|
||||
(λ (max-depth tasks)
|
||||
(success-k val stream last-consumed-token depth max-depth tasks next-k))))]))
|
||||
(define (new-fail-k max-depth tasks)
|
||||
#;(printf "Failure ~a\n" table-key)
|
||||
(hash-set! (tasks-cache tasks) table-key
|
||||
(λ (success-k fail-k max-depth tasks)
|
||||
(fail-k max-depth tasks)))
|
||||
(report-answer-all answer-key
|
||||
max-depth
|
||||
tasks
|
||||
null
|
||||
(λ (max-depth tasks)
|
||||
(fail-k max-depth tasks))))
|
||||
(k end max-depth tasks new-got-k new-fail-k))]))))
|
||||
|
||||
;; These temp identifiers can't be `gensym` or `generate-temporary`
|
||||
;; because they have to be consistent between module loads
|
||||
;; (IIUC, the parser is multi-threaded, and this approach is not thread-safe)
|
||||
;; so I see no alternative to the old standby of making them ludicrously unlikely
|
||||
(define-for-syntax start-id-temp 'start_jihqolbbafscgxvsufnepvmxqipnxgmlpxukmdoqxqzmzgaogaftbkbyqjttwwfimifowdxfyekjiixdmtprfkcvfciraehoeuaz)
|
||||
(define-for-syntax atok-id-temp 'atok_wrutdjgecmybyfipiwsgjlvsveryodlgassuzcargiuznzgdghrykfqfbwcjgzdhdoeqxcucmtjkuyucskzethozhqkasphdwbht)
|
||||
(define-syntax (cfg-parser stx)
|
||||
(syntax-case stx ()
|
||||
[(_ CLAUSE ...)
|
||||
(let ([clauses (syntax->list #'(CLAUSE ...))])
|
||||
(let-values ([(start grammar cfg-error parser-clauses src-pos?)
|
||||
(let ([all-toks (apply
|
||||
append
|
||||
(for/list ([clause (in-list clauses)])
|
||||
(syntax-case clause (tokens)
|
||||
[(tokens T ...)
|
||||
(apply
|
||||
append
|
||||
(for/list ([t (in-list (syntax->list #'(T ...)))])
|
||||
(define v (syntax-local-value t (λ () #f)))
|
||||
(cond
|
||||
[(terminals-def? v)
|
||||
(for/list ([v (in-list (syntax->list (terminals-def-t v)))])
|
||||
(cons v #f))]
|
||||
[(e-terminals-def? v)
|
||||
(for/list ([v (in-list (syntax->list (e-terminals-def-t v)))])
|
||||
(cons v #t))]
|
||||
[else null])))]
|
||||
[_else null])))]
|
||||
[all-end-toks (apply
|
||||
append
|
||||
(for/list ([clause (in-list clauses)])
|
||||
(syntax-case clause (end)
|
||||
[(end T ...)
|
||||
(syntax->list #'(T ...))]
|
||||
[_else null])))])
|
||||
(let loop ([clauses clauses]
|
||||
[cfg-start #f]
|
||||
[cfg-grammar #f]
|
||||
[cfg-error #f]
|
||||
[src-pos? #f]
|
||||
[parser-clauses null])
|
||||
(if (null? clauses)
|
||||
(values cfg-start
|
||||
cfg-grammar
|
||||
cfg-error
|
||||
(reverse parser-clauses)
|
||||
src-pos?)
|
||||
(syntax-case (car clauses) (start error grammar src-pos)
|
||||
[(start TOK)
|
||||
(loop (cdr clauses) #'TOK cfg-grammar cfg-error src-pos? parser-clauses)]
|
||||
[(error EXPR)
|
||||
(loop (cdr clauses) cfg-start cfg-grammar #'EXPR src-pos? parser-clauses)]
|
||||
[(grammar [NT [PAT HANDLE0 HANDLE ...] ...] ...)
|
||||
(let ([nts (make-bound-identifier-mapping)]
|
||||
[toks (make-token-identifier-mapping)]
|
||||
[end-toks (make-token-identifier-mapping)]
|
||||
[nt-ids (syntax->list #'(NT ...))]
|
||||
[patss (map (λ (stx)
|
||||
(map syntax->list (syntax->list stx)))
|
||||
(syntax->list #'((PAT ...) ...)))])
|
||||
(for ([nt (in-list nt-ids)])
|
||||
(bound-identifier-mapping-put! nts nt (list 0)))
|
||||
(for ([t (in-list all-end-toks)])
|
||||
(token-identifier-mapping-put! end-toks t #t))
|
||||
(for ([t (in-list all-toks)]
|
||||
#:unless (token-identifier-mapping-get end-toks (car t) (λ () #f)))
|
||||
(define id (gensym (syntax-e (car t))))
|
||||
(token-identifier-mapping-put! toks (car t) (cons id (cdr t))))
|
||||
;; Compute min max size for each non-term:
|
||||
(nt-fixpoint
|
||||
nts
|
||||
(λ (nt pats old-list)
|
||||
(let ([new-cnt
|
||||
(apply min (for/list ([pat (in-list pats)])
|
||||
(for/sum ([elem (in-list pat)])
|
||||
(car (bound-identifier-mapping-get
|
||||
nts elem (λ () (list 1)))))))])
|
||||
(if (new-cnt . > . (car old-list))
|
||||
(cons new-cnt (cdr old-list))
|
||||
old-list)))
|
||||
nt-ids patss)
|
||||
;; Compute set of toks that must appear at the beginning
|
||||
;; for a non-terminal
|
||||
(nt-fixpoint
|
||||
nts
|
||||
(λ (nt pats old-list)
|
||||
(let ([new-list
|
||||
(apply
|
||||
append
|
||||
(for/list ([pat (in-list pats)])
|
||||
(let loop ([pat pat])
|
||||
(if (pair? pat)
|
||||
(let ([l (bound-identifier-mapping-get
|
||||
nts
|
||||
(car pat)
|
||||
(λ ()
|
||||
(list 1 (map-token toks (car pat)))))])
|
||||
;; If the non-terminal can match 0 things,
|
||||
;; then it might match something from the
|
||||
;; next pattern element. Otherwise, it must
|
||||
;; match the first element:
|
||||
(if (zero? (car l))
|
||||
(append (cdr l) (loop (cdr pat)))
|
||||
(cdr l)))
|
||||
null))))])
|
||||
(let ([new (filter (λ (id)
|
||||
(andmap (λ (id2)
|
||||
(not (eq? id id2)))
|
||||
(cdr old-list)))
|
||||
new-list)])
|
||||
(if (pair? new)
|
||||
;; Drop dups in new list:
|
||||
(let ([new (let loop ([new new])
|
||||
(if (null? (cdr new))
|
||||
new
|
||||
(if (ormap (λ (id)
|
||||
(eq? (car new) id))
|
||||
(cdr new))
|
||||
(loop (cdr new))
|
||||
(cons (car new) (loop (cdr new))))))])
|
||||
(cons (car old-list) (append new (cdr old-list))))
|
||||
old-list))))
|
||||
nt-ids patss)
|
||||
;; Determine left-recursive clauses:
|
||||
(for-each (λ (nt pats)
|
||||
(let ([l (bound-identifier-mapping-get nts nt)])
|
||||
(bound-identifier-mapping-put! nts nt (list (car l)
|
||||
(cdr l)
|
||||
(map (λ (x) #f) pats)))))
|
||||
nt-ids patss)
|
||||
(nt-fixpoint
|
||||
nts
|
||||
(λ (nt pats old-list)
|
||||
(list (car old-list)
|
||||
(cadr old-list)
|
||||
(map (λ (pat simple?)
|
||||
(or simple?
|
||||
(let ([l (map (λ (elem)
|
||||
(bound-identifier-mapping-get
|
||||
nts
|
||||
elem
|
||||
(λ () #f)))
|
||||
pat)])
|
||||
(andmap (λ (i)
|
||||
(or (not i)
|
||||
(andmap values (caddr i))))
|
||||
l))))
|
||||
pats (caddr old-list))))
|
||||
nt-ids patss)
|
||||
;; Build a definition for each non-term:
|
||||
(loop (cdr clauses)
|
||||
cfg-start
|
||||
(map (λ (nt pats handles $ctxs)
|
||||
(define info (bound-identifier-mapping-get nts nt))
|
||||
(list nt
|
||||
#`(let ([key (gensym '#,nt)])
|
||||
(λ (stream last-consumed-token depth end success-k fail-k max-depth tasks)
|
||||
(parse-nt/share
|
||||
key #,(car info) '#,(cadr info) stream last-consumed-token depth end
|
||||
max-depth tasks
|
||||
success-k fail-k
|
||||
(λ (end max-depth tasks success-k fail-k)
|
||||
#,(let loop ([pats pats]
|
||||
[handles (syntax->list handles)]
|
||||
[$ctxs (syntax->list $ctxs)]
|
||||
[simple?s (caddr info)])
|
||||
(if (null? pats)
|
||||
#'(fail-k max-depth tasks)
|
||||
#`(#,(if (or (null? (cdr pats))
|
||||
(car simple?s))
|
||||
#'parse-or
|
||||
#'parse-parallel-or)
|
||||
(λ (stream last-consumed-token depth end success-k fail-k max-depth tasks)
|
||||
#,(build-match nts
|
||||
toks
|
||||
(car pats)
|
||||
(car handles)
|
||||
(car $ctxs)))
|
||||
(λ (stream last-consumed-token depth end success-k fail-k max-depth tasks)
|
||||
#,(loop (cdr pats)
|
||||
(cdr handles)
|
||||
(cdr $ctxs)
|
||||
(cdr simple?s)))
|
||||
stream last-consumed-token depth end success-k fail-k max-depth tasks)))))))))
|
||||
nt-ids
|
||||
patss
|
||||
(syntax->list #'(((begin HANDLE0 HANDLE ...) ...) ...))
|
||||
(syntax->list #'((HANDLE0 ...) ...)))
|
||||
cfg-error
|
||||
src-pos?
|
||||
(list*
|
||||
(with-syntax ([((tok tok-id . $e) ...)
|
||||
(token-identifier-mapping-map toks
|
||||
(λ (k v)
|
||||
(list* k
|
||||
(car v)
|
||||
(if (cdr v)
|
||||
#f
|
||||
'$1))))]
|
||||
[(pos ...)
|
||||
(if src-pos?
|
||||
#'($1-start-pos $1-end-pos)
|
||||
#'(#f #f))]
|
||||
;; rename `start` and `atok` to temp ids
|
||||
;; so that "start" and "atok" can be used as literal string tokens in a grammar.
|
||||
;; not sure why this works, but it passes all tests.
|
||||
[%start start-id-temp]
|
||||
[%atok atok-id-temp])
|
||||
#`(grammar (%start [() null]
|
||||
[(%atok %start) (cons $1 $2)])
|
||||
(%atok [(tok) (make-tok 'tok-id 'tok $e pos ...)] ...)))
|
||||
(with-syntax ([%start start-id-temp])
|
||||
#`(start %start))
|
||||
parser-clauses)))]
|
||||
[(grammar . _)
|
||||
(raise-syntax-error
|
||||
#f
|
||||
"bad grammar clause"
|
||||
stx
|
||||
(car clauses))]
|
||||
[(src-pos)
|
||||
(loop (cdr clauses)
|
||||
cfg-start
|
||||
cfg-grammar
|
||||
cfg-error
|
||||
#t
|
||||
(cons (car clauses) parser-clauses))]
|
||||
[_else
|
||||
(loop (cdr clauses)
|
||||
cfg-start
|
||||
cfg-grammar
|
||||
cfg-error
|
||||
src-pos?
|
||||
(cons (car clauses) parser-clauses))]))))])
|
||||
#`(let ([orig-parse (parser
|
||||
[error (λ (a b c)
|
||||
(error 'cfg-parser "unexpected ~a token: ~a" b c))]
|
||||
. #,parser-clauses)]
|
||||
[error-proc #,cfg-error])
|
||||
(letrec #,grammar
|
||||
(λ (get-tok)
|
||||
(let ([tok-list (orig-parse get-tok)])
|
||||
(letrec ([success-k
|
||||
(λ (val stream last-consumed-token depth max-depth tasks next)
|
||||
(if (null? stream)
|
||||
val
|
||||
(next success-k fail-k max-depth tasks)))]
|
||||
[fail-k (λ (max-depth tasks)
|
||||
(cond
|
||||
[(null? tok-list)
|
||||
(if error-proc
|
||||
(error-proc #t
|
||||
'no-tokens
|
||||
#f
|
||||
(make-position #f #f #f)
|
||||
(make-position #f #f #f))
|
||||
(error
|
||||
'cfg-parse
|
||||
"no tokens"))]
|
||||
[else
|
||||
(let ([bad-tok (list-ref tok-list
|
||||
(min (sub1 (length tok-list))
|
||||
max-depth))])
|
||||
(if error-proc
|
||||
(error-proc #t
|
||||
(tok-orig-name bad-tok)
|
||||
(tok-val bad-tok)
|
||||
(tok-start bad-tok)
|
||||
(tok-end bad-tok))
|
||||
(error
|
||||
'cfg-parse
|
||||
"failed at ~a"
|
||||
(tok-val bad-tok))))]))])
|
||||
(#,start tok-list
|
||||
;; we simulate a token at the very beginning with zero width
|
||||
;; for use with the position-generating code (*-start-pos, *-end-pos).
|
||||
(if (null? tok-list)
|
||||
(tok #f #f #f
|
||||
(position 1
|
||||
#,(if src-pos? #'1 #'#f)
|
||||
#,(if src-pos? #'0 #'#f))
|
||||
(position 1
|
||||
#,(if src-pos? #'1 #'#f)
|
||||
#,(if src-pos? #'0 #'#f)))
|
||||
(tok (tok-name (car tok-list))
|
||||
(tok-orig-name (car tok-list))
|
||||
(tok-val (car tok-list))
|
||||
(tok-start (car tok-list))
|
||||
(tok-start (car tok-list))))
|
||||
0
|
||||
(length tok-list)
|
||||
success-k
|
||||
fail-k
|
||||
0
|
||||
(make-tasks null null
|
||||
(make-hasheq) (make-hasheq)
|
||||
(make-hash) #t)))))))))]))
|
||||
|
||||
|
||||
(module* test racket/base
|
||||
(require (submod "..")
|
||||
br-parser-tools/lex
|
||||
racket/block
|
||||
rackunit)
|
||||
|
||||
;; Test: parsing regular expressions.
|
||||
;; Here is a test case on locations:
|
||||
(block
|
||||
(define-tokens regexp-tokens (ANCHOR STAR OR LIT LPAREN RPAREN EOF))
|
||||
(define lex (lexer-src-pos ["|" (token-OR lexeme)]
|
||||
["^" (token-ANCHOR lexeme)]
|
||||
["*" (token-STAR lexeme)]
|
||||
[(repetition 1 +inf.0 alphabetic) (token-LIT lexeme)]
|
||||
["(" (token-LPAREN lexeme)]
|
||||
[")" (token-RPAREN lexeme)]
|
||||
[whitespace (return-without-pos (lex input-port))]
|
||||
[(eof) (token-EOF 'eof)]))
|
||||
(define -parse (cfg-parser
|
||||
(tokens regexp-tokens)
|
||||
(start top)
|
||||
(end EOF)
|
||||
(src-pos)
|
||||
(grammar [top [(maybe-anchor regexp)
|
||||
(cond [$1
|
||||
`(anchored ,$2 ,(pos->sexp $1-start-pos) ,(pos->sexp $2-end-pos))]
|
||||
[else
|
||||
`(unanchored ,$2 ,(pos->sexp $1-start-pos) ,(pos->sexp $2-end-pos))])]]
|
||||
[maybe-anchor [(ANCHOR) #t]
|
||||
[() #f]]
|
||||
[regexp [(regexp STAR) `(star ,$1 ,(pos->sexp $1-start-pos) ,(pos->sexp $2-end-pos))]
|
||||
[(regexp OR regexp) `(or ,$1 ,$3 ,(pos->sexp $1-start-pos) ,(pos->sexp $3-end-pos))]
|
||||
[(LPAREN regexp RPAREN) `(group ,$2 ,(pos->sexp $1-start-pos) ,(pos->sexp $3-end-pos))]
|
||||
[(LIT) `(lit ,$1 ,(pos->sexp $1-start-pos) ,(pos->sexp $1-end-pos))]])))
|
||||
(define (pos->sexp pos)
|
||||
(position-offset pos))
|
||||
|
||||
(define (parse s)
|
||||
(define ip (open-input-string s))
|
||||
(port-count-lines! ip)
|
||||
(-parse (λ () (lex ip))))
|
||||
|
||||
(check-equal? (parse "abc")
|
||||
'(unanchored (lit "abc" 1 4) 1 4))
|
||||
(check-equal? (parse "a | (b*) | c")
|
||||
'(unanchored (or (or (lit "a" 1 2)
|
||||
(group (star (lit "b" 6 7) 6 8) 5 9)
|
||||
1 9)
|
||||
(lit "c" 12 13)
|
||||
1 13)
|
||||
1 13)))
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
;; Tests used during development
|
||||
(define-tokens non-terminals (PLUS MINUS STAR BAR COLON EOF))
|
||||
|
||||
(define lex
|
||||
(lexer
|
||||
["+" (token-PLUS '+)]
|
||||
["-" (token-MINUS '-)]
|
||||
["*" (token-STAR '*)]
|
||||
["|" (token-BAR '||)]
|
||||
[":" (token-COLON '|:|)]
|
||||
[whitespace (lex input-port)]
|
||||
[(eof) (token-EOF 'eof)]))
|
||||
|
||||
(define parse
|
||||
(cfg-parser
|
||||
(tokens non-terminals)
|
||||
(start <program>)
|
||||
(end EOF)
|
||||
(error (λ (a b stx)
|
||||
(error 'parse "failed at ~s" stx)))
|
||||
(grammar [<program> [(PLUS) "plus"]
|
||||
[(<minus-program> BAR <minus-program>) (list $1 $2 $3)]
|
||||
[(<program> COLON) (list $1)]]
|
||||
[<minus-program> [(MINUS) "minus"]
|
||||
[(<program> STAR) (cons $1 $2)]]
|
||||
[<simple> [(<alts> <alts> <alts> MINUS) "yes"]]
|
||||
[<alts> [(PLUS) 'plus]
|
||||
[(MINUS) 'minus]]
|
||||
[<random> [() '0]
|
||||
[(<random> PLUS) (add1 $1)]
|
||||
[(<random> PLUS) (add1 $1)]])))
|
||||
|
||||
(let ([p (open-input-string #;"+*|-|-*|+**" #;"-|+*|+**"
|
||||
#;"+*|+**|-" #;"-|-*|-|-*"
|
||||
#;"-|-*|-|-**|-|-*|-|-**"
|
||||
"-|-*|-|-**|-|-*|-|-***|-|-*|-|-**|-|-*|-|-****|-|-*|-|-**|-|-*|-|-***
|
||||
|-|-*|-|-**|-|-*|-|-*****|-|-*|-|-**|-|-*|-|-***|-|-*|-|-**|-|-*|-|-****|
|
||||
-|-*|-|-**|-|-*|-|-***|-|-*|-|-**|-|-*|-|-*****"
|
||||
;; This one fails:
|
||||
#;"+*")])
|
||||
(check-equal? (parse (λ () (lex p)))
|
||||
'((((((((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *)
|
||||
||
|
||||
(((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *))
|
||||
.
|
||||
*)
|
||||
||
|
||||
(((((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *)
|
||||
||
|
||||
(((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *))
|
||||
.
|
||||
*))
|
||||
.
|
||||
*)
|
||||
||
|
||||
(((((((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *)
|
||||
||
|
||||
(((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *))
|
||||
.
|
||||
*)
|
||||
||
|
||||
(((((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *)
|
||||
||
|
||||
(((((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *) || (((("minus" || "minus") . *) || (("minus" || "minus") . *)) . *)) . *))
|
||||
.
|
||||
*))
|
||||
.
|
||||
*)))))
|
||||
@ -0,0 +1,92 @@
|
||||
#lang racket/base
|
||||
|
||||
;; An interactive calculator inspired by the calculator example in the bison manual.
|
||||
|
||||
|
||||
;; Import the parser and lexer generators.
|
||||
(require br-parser-tools/yacc
|
||||
br-parser-tools/lex
|
||||
(prefix-in : br-parser-tools/lex-sre))
|
||||
|
||||
(define-tokens value-tokens (NUM VAR FNCT))
|
||||
(define-empty-tokens op-tokens (newline = OP CP + - * / ^ EOF NEG))
|
||||
|
||||
;; A hash table to store variable values in for the calculator
|
||||
(define vars (make-hash))
|
||||
|
||||
(define-lex-abbrevs
|
||||
(lower-letter (:/ "a" "z"))
|
||||
|
||||
(upper-letter (:/ #\A #\Z))
|
||||
|
||||
;; (:/ 0 9) would not work because the lexer does not understand numbers. (:/ #\0 #\9) is ok too.
|
||||
(digit (:/ "0" "9")))
|
||||
|
||||
(define calc-lex
|
||||
(lexer
|
||||
[(eof) 'EOF]
|
||||
;; recursively call the lexer on the remaining input after a tab or space. Returning the
|
||||
;; result of that operation. This effectively skips all whitespace.
|
||||
[(:or #\tab #\space) (calc-lex input-port)]
|
||||
;; (token-newline) returns 'newline
|
||||
[#\newline (token-newline)]
|
||||
;; Since (token-=) returns '=, just return the symbol directly
|
||||
[(:or "=" "+" "-" "*" "/" "^") (string->symbol lexeme)]
|
||||
["(" 'OP]
|
||||
[")" 'CP]
|
||||
["sin" (token-FNCT sin)]
|
||||
[(:+ (:or lower-letter upper-letter)) (token-VAR (string->symbol lexeme))]
|
||||
[(:+ digit) (token-NUM (string->number lexeme))]
|
||||
[(:: (:+ digit) #\. (:* digit)) (token-NUM (string->number lexeme))]))
|
||||
|
||||
|
||||
(define calc-parse
|
||||
(parser
|
||||
|
||||
(start start)
|
||||
(end newline EOF)
|
||||
(tokens value-tokens op-tokens)
|
||||
(error (lambda (a b c) (void)))
|
||||
|
||||
(precs (right =)
|
||||
(left - +)
|
||||
(left * /)
|
||||
(left NEG)
|
||||
(right ^))
|
||||
|
||||
(grammar
|
||||
|
||||
(start [() #f]
|
||||
;; If there is an error, ignore everything before the error
|
||||
;; and try to start over right after the error
|
||||
[(error start) $2]
|
||||
[(exp) $1])
|
||||
|
||||
(exp [(NUM) $1]
|
||||
[(VAR) (hash-ref vars $1 (lambda () 0))]
|
||||
[(VAR = exp) (begin (hash-set! vars $1 $3)
|
||||
$3)]
|
||||
[(FNCT OP exp CP) ($1 $3)]
|
||||
[(exp + exp) (+ $1 $3)]
|
||||
[(exp - exp) (- $1 $3)]
|
||||
[(exp * exp) (* $1 $3)]
|
||||
[(exp / exp) (/ $1 $3)]
|
||||
[(- exp) (prec NEG) (- $2)]
|
||||
[(exp ^ exp) (expt $1 $3)]
|
||||
[(OP exp CP) $2]))))
|
||||
|
||||
;; run the calculator on the given input-port
|
||||
(define (calc ip)
|
||||
(port-count-lines! ip)
|
||||
(let loop ()
|
||||
(define result (calc-parse (λ () (calc-lex ip))))
|
||||
(when result
|
||||
(printf "~a\n" result)
|
||||
(loop))))
|
||||
|
||||
(module+ test
|
||||
(require rackunit)
|
||||
(check-equal? (let ([o (open-output-string)])
|
||||
(parameterize ([current-output-port o])
|
||||
(calc (open-input-string "x=1\n(x + 2 * 3) - (1+2)*3")))
|
||||
(get-output-string o)) "1\n-2\n"))
|
||||
@ -0,0 +1,240 @@
|
||||
#lang racket/base
|
||||
;; This implements the equivalent of racket's read-syntax for R5RS scheme.
|
||||
;; It has not been thoroughly tested. Also it will read an entire file into a
|
||||
;; list of syntax objects, instead of returning one syntax object at a time
|
||||
|
||||
(require (for-syntax racket/base)
|
||||
br-parser-tools/lex
|
||||
(prefix-in : br-parser-tools/lex-sre)
|
||||
br-parser-tools/yacc
|
||||
syntax/readerr)
|
||||
|
||||
(define-tokens data (DATUM))
|
||||
(define-empty-tokens delim (OP CP HASHOP QUOTE QUASIQUOTE UNQUOTE UNQUOTE-SPLICING DOT EOF))
|
||||
|
||||
(define scheme-lexer
|
||||
(lexer-src-pos
|
||||
|
||||
;; Skip comments, without accumulating extra position information
|
||||
[(:or scheme-whitespace comment) (return-without-pos (scheme-lexer input-port))]
|
||||
|
||||
["#t" (token-DATUM #t)]
|
||||
["#f" (token-DATUM #f)]
|
||||
[(:: "#\\" any-char) (token-DATUM (caddr (string->list lexeme)))]
|
||||
["#\\space" (token-DATUM #\space)]
|
||||
["#\\newline" (token-DATUM #\newline)]
|
||||
[(:or (:: initial (:* subsequent)) "+" "-" "...") (token-DATUM (string->symbol lexeme))]
|
||||
[#\" (token-DATUM (list->string (get-string-token input-port)))]
|
||||
[#\( 'OP]
|
||||
[#\) 'CP]
|
||||
[#\[ 'OP]
|
||||
[#\] 'CP]
|
||||
["#(" 'HASHOP]
|
||||
[num2 (token-DATUM (string->number lexeme 2))]
|
||||
[num8 (token-DATUM (string->number lexeme 8))]
|
||||
[num10 (token-DATUM (string->number lexeme 10))]
|
||||
[num16 (token-DATUM (string->number lexeme 16))]
|
||||
["'" 'QUOTE]
|
||||
["`" 'QUASIQUOTE]
|
||||
["," 'UNQUOTE]
|
||||
[",@" 'UNQUOTE-SPLICING]
|
||||
["." 'DOT]
|
||||
[(eof) 'EOF]))
|
||||
|
||||
(define get-string-token
|
||||
(lexer
|
||||
[(:~ #\" #\\) (cons (car (string->list lexeme))
|
||||
(get-string-token input-port))]
|
||||
[(:: #\\ #\\) (cons #\\ (get-string-token input-port))]
|
||||
[(:: #\\ #\") (cons #\" (get-string-token input-port))]
|
||||
[#\" null]))
|
||||
|
||||
|
||||
(define-lex-abbrevs
|
||||
[letter (:or (:/ "a" "z") (:/ #\A #\Z))]
|
||||
[digit (:/ #\0 #\9)]
|
||||
[scheme-whitespace (:or #\newline #\return #\tab #\space #\vtab)]
|
||||
[initial (:or letter (char-set "!$%&*/:<=>?^_~@"))]
|
||||
[subsequent (:or initial digit (char-set "+-.@"))]
|
||||
[comment (:: #\; (:* (:~ #\newline)) #\newline)]
|
||||
|
||||
|
||||
;; See ${PLTHOME}/collects/syntax-color/racket-lexer.rkt for an example of
|
||||
;; using regexp macros to avoid the cut and paste.
|
||||
; [numR (:: prefixR complexR)]
|
||||
; [complexR (:or realR
|
||||
; (:: realR "@" realR)
|
||||
; (:: realR "+" urealR "i")
|
||||
; (:: realR "-" urealR "i")
|
||||
; (:: realR "+i")
|
||||
; (:: realR "-i")
|
||||
; (:: "+" urealR "i")
|
||||
; (:: "-" urealR "i")
|
||||
; (:: "+i")
|
||||
; (:: "-i"))]
|
||||
; [realR (:: sign urealR)]
|
||||
; [urealR (:or uintegerR (:: uintegerR "/" uintegerR) decimalR)]
|
||||
; [uintegerR (:: (:+ digitR) (:* #\#))]
|
||||
; [prefixR (:or (:: radixR exactness)
|
||||
; (:: exactness radixR))]
|
||||
|
||||
[num2 (:: prefix2 complex2)]
|
||||
[complex2 (:or real2
|
||||
(:: real2 "@" real2)
|
||||
(:: real2 "+" ureal2 "i")
|
||||
(:: real2 "-" ureal2 "i")
|
||||
(:: real2 "+i")
|
||||
(:: real2 "-i")
|
||||
(:: "+" ureal2 "i")
|
||||
(:: "-" ureal2 "i")
|
||||
(:: "+i")
|
||||
(:: "-i"))]
|
||||
[real2 (:: sign ureal2)]
|
||||
[ureal2 (:or uinteger2 (:: uinteger2 "/" uinteger2))]
|
||||
[uinteger2 (:: (:+ digit2) (:* #\#))]
|
||||
[prefix2 (:or (:: radix2 exactness)
|
||||
(:: exactness radix2))]
|
||||
[radix2 "#b"]
|
||||
[digit2 (:or "0" "1")]
|
||||
[num8 (:: prefix8 complex8)]
|
||||
[complex8 (:or real8
|
||||
(:: real8 "@" real8)
|
||||
(:: real8 "+" ureal8 "i")
|
||||
(:: real8 "-" ureal8 "i")
|
||||
(:: real8 "+i")
|
||||
(:: real8 "-i")
|
||||
(:: "+" ureal8 "i")
|
||||
(:: "-" ureal8 "i")
|
||||
(:: "+i")
|
||||
(:: "-i"))]
|
||||
[real8 (:: sign ureal8)]
|
||||
[ureal8 (:or uinteger8 (:: uinteger8 "/" uinteger8))]
|
||||
[uinteger8 (:: (:+ digit8) (:* #\#))]
|
||||
[prefix8 (:or (:: radix8 exactness)
|
||||
(:: exactness radix8))]
|
||||
[radix8 "#o"]
|
||||
[digit8 (:/ "0" "7")]
|
||||
|
||||
[num10 (:: prefix10 complex10)]
|
||||
[complex10 (:or real10
|
||||
(:: real10 "@" real10)
|
||||
(:: real10 "+" ureal10 "i")
|
||||
(:: real10 "-" ureal10 "i")
|
||||
(:: real10 "+i")
|
||||
(:: real10 "-i")
|
||||
(:: "+" ureal10 "i")
|
||||
(:: "-" ureal10 "i")
|
||||
(:: "+i")
|
||||
(:: "-i"))]
|
||||
[real10 (:: sign ureal10)]
|
||||
[ureal10 (:or uinteger10 (:: uinteger10 "/" uinteger10) decimal10)]
|
||||
[uinteger10 (:: (:+ digit10) (:* #\#))]
|
||||
[prefix10 (:or (:: radix10 exactness)
|
||||
(:: exactness radix10))]
|
||||
[radix10 (:? "#d")]
|
||||
[digit10 digit]
|
||||
[decimal10 (:or (:: uinteger10 suffix)
|
||||
(:: #\. (:+ digit10) (:* #\#) suffix)
|
||||
(:: (:+ digit10) #\. (:* digit10) (:* #\#) suffix)
|
||||
(:: (:+ digit10) (:+ #\#) #\. (:* #\#) suffix))]
|
||||
|
||||
[num16 (:: prefix16 complex16)]
|
||||
[complex16 (:or real16
|
||||
(:: real16 "@" real16)
|
||||
(:: real16 "+" ureal16 "i")
|
||||
(:: real16 "-" ureal16 "i")
|
||||
(:: real16 "+i")
|
||||
(:: real16 "-i")
|
||||
(:: "+" ureal16 "i")
|
||||
(:: "-" ureal16 "i")
|
||||
"+i"
|
||||
"-i")]
|
||||
[real16 (:: sign ureal16)]
|
||||
[ureal16 (:or uinteger16 (:: uinteger16 "/" uinteger16))]
|
||||
[uinteger16 (:: (:+ digit16) (:* #\#))]
|
||||
[prefix16 (:or (:: radix16 exactness)
|
||||
(:: exactness radix16))]
|
||||
[radix16 "#x"]
|
||||
[digit16 (:or digit (:/ #\a #\f) (:/ #\A #\F))]
|
||||
|
||||
|
||||
[suffix (:or "" (:: exponent-marker sign (:+ digit10)))]
|
||||
[exponent-marker (:or "e" "s" "f" "d" "l")]
|
||||
[sign (:or "" "+" "-")]
|
||||
[exactness (:or "" "#i" "#e")])
|
||||
|
||||
|
||||
(define stx-for-original-property (read-syntax #f (open-input-string "original")))
|
||||
|
||||
;; A macro to build the syntax object
|
||||
(define-syntax (build-so stx)
|
||||
(syntax-case stx ()
|
||||
((_ value start end)
|
||||
(with-syntax ((start-pos (datum->syntax
|
||||
#'end
|
||||
(string->symbol
|
||||
(format "$~a-start-pos"
|
||||
(syntax->datum #'start)))))
|
||||
(end-pos (datum->syntax
|
||||
#'end
|
||||
(string->symbol
|
||||
(format "$~a-end-pos"
|
||||
(syntax->datum #'end)))))
|
||||
(source (datum->syntax
|
||||
#'end
|
||||
'source-name)))
|
||||
(syntax
|
||||
(datum->syntax
|
||||
#f
|
||||
value
|
||||
(list source
|
||||
(position-line start-pos)
|
||||
(position-col start-pos)
|
||||
(position-offset start-pos)
|
||||
(- (position-offset end-pos)
|
||||
(position-offset start-pos)))
|
||||
stx-for-original-property))))))
|
||||
|
||||
(define (scheme-parser source-name)
|
||||
(parser
|
||||
(src-pos)
|
||||
|
||||
(start s)
|
||||
(end EOF)
|
||||
(error (lambda (a name val start end)
|
||||
(raise-read-error
|
||||
"read-error"
|
||||
source-name
|
||||
(position-line start)
|
||||
(position-col start)
|
||||
(position-offset start)
|
||||
(- (position-offset end)
|
||||
(position-offset start)))))
|
||||
(tokens data delim)
|
||||
|
||||
|
||||
(grammar
|
||||
|
||||
(s [(sexp-list) (reverse $1)])
|
||||
|
||||
(sexp [(DATUM) (build-so $1 1 1)]
|
||||
[(OP sexp-list CP) (build-so (reverse $2) 1 3)]
|
||||
[(HASHOP sexp-list CP) (build-so (list->vector (reverse $2)) 1 3)]
|
||||
[(QUOTE sexp) (build-so (list 'quote $2) 1 2)]
|
||||
[(QUASIQUOTE sexp) (build-so (list 'quasiquote $2) 1 2)]
|
||||
[(UNQUOTE sexp) (build-so (list 'unquote $2) 1 2)]
|
||||
[(UNQUOTE-SPLICING sexp) (build-so (list 'unquote-splicing $2) 1 2)]
|
||||
[(OP sexp-list DOT sexp CP) (build-so (append (reverse $2) $4) 1 5)])
|
||||
|
||||
(sexp-list [() null]
|
||||
[(sexp-list sexp) (cons $2 $1)]))))
|
||||
|
||||
(define (rs sn ip)
|
||||
(port-count-lines! ip)
|
||||
((scheme-parser sn) (lambda () (scheme-lexer ip))))
|
||||
|
||||
(define readsyntax
|
||||
(case-lambda ((sn) (rs sn (current-input-port)))
|
||||
((sn ip) (rs sn ip))))
|
||||
|
||||
(provide (rename-out [readsyntax read-syntax]))
|
||||
@ -0,0 +1,3 @@
|
||||
#lang info
|
||||
|
||||
(define compile-omit-paths '("private-lex/error-tests.rkt"))
|
||||
@ -0,0 +1,23 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base)
|
||||
br-parser-tools/lex
|
||||
(prefix-in : br-parser-tools/lex-sre))
|
||||
|
||||
(provide epsilon ~
|
||||
(rename-out [:* *]
|
||||
[:+ +]
|
||||
[:? ?]
|
||||
[:or :]
|
||||
[:& &]
|
||||
[:: @]
|
||||
[:~ ^]
|
||||
[:/ -]))
|
||||
|
||||
(define-lex-trans (epsilon stx)
|
||||
(syntax-case stx ()
|
||||
[(_) #'""]))
|
||||
|
||||
(define-lex-trans (~ stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE) #'(complement RE)]))
|
||||
|
||||
@ -0,0 +1,103 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base)
|
||||
br-parser-tools/lex)
|
||||
|
||||
(provide (rename-out [sre-* *]
|
||||
[sre-+ +]
|
||||
[sre-= =]
|
||||
[sre->= >=]
|
||||
[sre-or or]
|
||||
[sre-- -]
|
||||
[sre-/ /])
|
||||
? ** : seq & ~ /-only-chars)
|
||||
|
||||
(define-lex-trans (sre-* stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(repetition 0 +inf.0 (union RE ...))]))
|
||||
|
||||
(define-lex-trans (sre-+ stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(repetition 1 +inf.0 (union RE ...))]))
|
||||
|
||||
(define-lex-trans (? stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(repetition 0 1 (union RE ...))]))
|
||||
|
||||
(define-lex-trans (sre-= stx)
|
||||
(syntax-case stx ()
|
||||
[(_ N RE ...)
|
||||
#'(repetition N N (union RE ...))]))
|
||||
|
||||
(define-lex-trans (sre->= stx)
|
||||
(syntax-case stx ()
|
||||
[(_ N RE ...)
|
||||
#'(repetition N +inf.0 (union RE ...))]))
|
||||
|
||||
(define-lex-trans (** stx)
|
||||
(syntax-case stx ()
|
||||
[(_ LOW #f RE ...)
|
||||
#'(** LOW +inf.0 RE ...)]
|
||||
[(_ LOW HIGH RE ...)
|
||||
#'(repetition LOW HIGH (union RE ...))]))
|
||||
|
||||
(define-lex-trans (sre-or stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(union RE ...)]))
|
||||
|
||||
(define-lex-trans (: stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(concatenation RE ...)]))
|
||||
|
||||
(define-lex-trans (seq stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(concatenation RE ...)]))
|
||||
|
||||
(define-lex-trans (& stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(intersection RE ...)]))
|
||||
|
||||
(define-lex-trans (~ stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RE ...)
|
||||
#'(char-complement (union RE ...))]))
|
||||
|
||||
;; set difference
|
||||
(define-lex-trans (sre-- stx)
|
||||
(syntax-case stx ()
|
||||
[(_)
|
||||
(raise-syntax-error #f
|
||||
"must have at least one argument"
|
||||
stx)]
|
||||
[(_ BIG-RE RE ...)
|
||||
#'(& BIG-RE (complement (union RE ...)))]))
|
||||
|
||||
(define-lex-trans (sre-/ stx)
|
||||
(syntax-case stx ()
|
||||
[(_ RANGE ...)
|
||||
(let ([chars
|
||||
(apply append (for/list ([r (in-list (syntax->list #'(RANGE ...)))])
|
||||
(let ([x (syntax-e r)])
|
||||
(cond
|
||||
[(char? x) (list x)]
|
||||
[(string? x) (string->list x)]
|
||||
[else
|
||||
(raise-syntax-error #f "not a char or string" stx r)]))))])
|
||||
(unless (even? (length chars))
|
||||
(raise-syntax-error #f "not given an even number of characters" stx))
|
||||
#`(/-only-chars #,@chars))]))
|
||||
|
||||
(define-lex-trans (/-only-chars stx)
|
||||
(syntax-case stx ()
|
||||
[(_ C1 C2)
|
||||
#'(char-range C1 C2)]
|
||||
[(_ C1 C2 C ...)
|
||||
#'(union (char-range C1 C2) (/-only-chars C ...))]))
|
||||
|
||||
|
||||
@ -0,0 +1,370 @@
|
||||
#lang racket/base
|
||||
|
||||
;; Provides the syntax used to create lexers and the functions needed to
|
||||
;; create and use the buffer that the lexer reads from. See docs.
|
||||
|
||||
(require (for-syntax racket/list
|
||||
racket/syntax
|
||||
syntax/stx
|
||||
syntax/define
|
||||
syntax/boundmap
|
||||
"private-lex/util.rkt"
|
||||
"private-lex/actions.rkt"
|
||||
"private-lex/front.rkt"
|
||||
"private-lex/unicode-chars.rkt"
|
||||
racket/base
|
||||
racket/promise))
|
||||
|
||||
(require racket/stxparam
|
||||
syntax/readerr
|
||||
"private-lex/token.rkt")
|
||||
|
||||
(provide lexer lexer-src-pos lexer-srcloc define-lex-abbrev define-lex-abbrevs define-lex-trans
|
||||
|
||||
;; Dealing with tokens and related structures
|
||||
define-tokens define-empty-tokens token-name token-value token?
|
||||
(struct-out position)
|
||||
(struct-out position-token)
|
||||
(struct-out srcloc-token)
|
||||
|
||||
;; File path for highlighting errors while lexing
|
||||
file-path
|
||||
lexer-file-path ;; alternate name
|
||||
|
||||
;; Lex abbrevs for unicode char sets.
|
||||
any-char any-string nothing alphabetic lower-case upper-case title-case
|
||||
numeric symbolic punctuation graphic whitespace blank iso-control
|
||||
|
||||
;; A regular expression operator
|
||||
char-set)
|
||||
|
||||
;; wrap-action: syntax-object src-pos? -> syntax-object
|
||||
(define-for-syntax (wrap-action action src-loc-style)
|
||||
(with-syntax ([action-stx
|
||||
(cond
|
||||
[(eq? src-loc-style 'lexer-src-pos)
|
||||
#`(let/ec ret
|
||||
(syntax-parameterize
|
||||
([return-without-pos (make-rename-transformer #'ret)])
|
||||
(make-position-token #,action start-pos end-pos)))]
|
||||
[(eq? src-loc-style 'lexer-srcloc)
|
||||
#`(let/ec ret
|
||||
(syntax-parameterize
|
||||
([return-without-srcloc (make-rename-transformer #'ret)])
|
||||
(make-srcloc-token #,action lexeme-srcloc)))]
|
||||
[else action])])
|
||||
(syntax/loc action
|
||||
(λ (start-pos-p end-pos-p lexeme-p input-port-p)
|
||||
(define lexeme-srcloc-p (make-srcloc (object-name input-port-p)
|
||||
(position-line start-pos-p)
|
||||
(position-col start-pos-p)
|
||||
(position-offset start-pos-p)
|
||||
(and (number? (position-offset end-pos-p))
|
||||
(number? (position-offset start-pos-p))
|
||||
(- (position-offset end-pos-p)
|
||||
(position-offset start-pos-p)))))
|
||||
(syntax-parameterize
|
||||
([start-pos (make-rename-transformer #'start-pos-p)]
|
||||
[end-pos (make-rename-transformer #'end-pos-p)]
|
||||
[lexeme (make-rename-transformer #'lexeme-p)]
|
||||
[input-port (make-rename-transformer #'input-port-p)]
|
||||
[lexeme-srcloc (make-rename-transformer #'lexeme-srcloc-p)])
|
||||
action-stx)))))
|
||||
|
||||
(define-for-syntax (make-lexer-macro caller src-loc-style)
|
||||
(λ (stx)
|
||||
(syntax-case stx ()
|
||||
[(_ . RE+ACTS)
|
||||
(with-disappeared-uses
|
||||
(let ()
|
||||
(define spec/re-acts (syntax->list #'RE+ACTS))
|
||||
(for/and ([x (in-list spec/re-acts)])
|
||||
(syntax-case x ()
|
||||
[(RE ACT) #t]
|
||||
[else (raise-syntax-error caller "not a regular expression / action pair" stx x)]))
|
||||
(define eof-act (get-special-action spec/re-acts #'eof (case src-loc-style
|
||||
[(lexer-src-pos) #'(return-without-pos eof)]
|
||||
[(lexer-srcloc) #'(return-without-srcloc eof)]
|
||||
[else #'eof])))
|
||||
(define spec-act (get-special-action spec/re-acts #'special #'(void)))
|
||||
(define spec-comment-act (get-special-action spec/re-acts #'special-comment #'#f))
|
||||
(define ids (list #'special #'special-comment #'eof))
|
||||
(define re-acts (filter (λ (spec/re-act)
|
||||
(syntax-case spec/re-act ()
|
||||
[((special) act)
|
||||
(not (ormap
|
||||
(λ (x)
|
||||
(and (identifier? #'special)
|
||||
(module-or-top-identifier=? #'special x)))
|
||||
ids))]
|
||||
[_ #t])) spec/re-acts))
|
||||
(define names (map (λ (x) (datum->syntax #f (gensym))) re-acts))
|
||||
(define acts (map (λ (x) (stx-car (stx-cdr x))) re-acts))
|
||||
(define re-actnames (map (λ (re-act name) (list (stx-car re-act) name)) re-acts names))
|
||||
(when (null? spec/re-acts)
|
||||
(raise-syntax-error caller "expected at least one action" stx))
|
||||
(define-values (trans start action-names no-look) (build-lexer re-actnames))
|
||||
(when (vector-ref action-names start) ;; Start state is final
|
||||
(unless (and
|
||||
;; All the successor states are final
|
||||
(vector? (vector-ref trans start))
|
||||
(andmap (λ (x) (vector-ref action-names (vector-ref x 2)))
|
||||
(vector->list (vector-ref trans start)))
|
||||
;; Each character has a successor state
|
||||
(let loop ([check 0]
|
||||
[nexts (vector->list (vector-ref trans start))])
|
||||
(cond
|
||||
[(null? nexts) #f]
|
||||
[else
|
||||
(let ([next (car nexts)])
|
||||
(and (= (vector-ref next 0) check)
|
||||
(let ([next-check (vector-ref next 1)])
|
||||
(or (>= next-check max-char-num)
|
||||
(loop (add1 next-check) (cdr nexts))))))])))
|
||||
(eprintf "warning: lexer at ~a can accept the empty string\n" stx)))
|
||||
(with-syntax ([START-STATE-STX start]
|
||||
[TRANS-TABLE-STX trans]
|
||||
[NO-LOOKAHEAD-STX no-look]
|
||||
[(NAME ...) names]
|
||||
[(ACT ...) (map (λ (a) (wrap-action a src-loc-style)) acts)]
|
||||
[(ACT-NAME ...) (vector->list action-names)]
|
||||
[SPEC-ACT-STX (wrap-action spec-act src-loc-style)]
|
||||
[HAS-COMMENT-ACT?-STX (if (syntax-e spec-comment-act) #t #f)]
|
||||
[SPEC-COMMENT-ACT-STX (wrap-action spec-comment-act src-loc-style)]
|
||||
[EOF-ACT-STX (wrap-action eof-act src-loc-style)])
|
||||
(syntax/loc stx (let ([NAME ACT] ...)
|
||||
(let ([proc (lexer-body START-STATE-STX
|
||||
TRANS-TABLE-STX
|
||||
(vector ACT-NAME ...)
|
||||
NO-LOOKAHEAD-STX
|
||||
SPEC-ACT-STX
|
||||
HAS-COMMENT-ACT?-STX
|
||||
SPEC-COMMENT-ACT-STX
|
||||
EOF-ACT-STX)])
|
||||
;; reverse eta to get named procedures:
|
||||
(λ (port) (proc port))))))))])))
|
||||
|
||||
(define-syntax lexer (make-lexer-macro 'lexer #f))
|
||||
(define-syntax lexer-src-pos (make-lexer-macro 'lexer-src-pos 'lexer-src-pos))
|
||||
(define-syntax lexer-srcloc (make-lexer-macro 'lexer-srcloc 'lexer-srcloc))
|
||||
|
||||
(define-syntax (define-lex-abbrev stx)
|
||||
(syntax-case stx ()
|
||||
[(_ NAME RE) (identifier? #'NAME)
|
||||
(syntax/loc stx
|
||||
(define-syntax NAME
|
||||
(make-lex-abbrev (λ () (quote-syntax RE)))))]
|
||||
[_ (raise-syntax-error 'define-lex-abbrev "form should be (define-lex-abbrev name re)" stx)]))
|
||||
|
||||
(define-syntax (define-lex-abbrevs stx)
|
||||
(syntax-case stx ()
|
||||
[(_ . XS)
|
||||
(with-syntax ([(ABBREV ...) (map
|
||||
(λ (a)
|
||||
(syntax-case a ()
|
||||
[(NAME RE) (identifier? #'NAME)
|
||||
(syntax/loc a (define-lex-abbrev NAME RE))]
|
||||
[_ (raise-syntax-error
|
||||
#f
|
||||
"form should be (define-lex-abbrevs (name re) ...)"
|
||||
stx
|
||||
a)]))
|
||||
(syntax->list #'XS))])
|
||||
(syntax/loc stx (begin ABBREV ...)))]
|
||||
[_ (raise-syntax-error #f "form should be (define-lex-abbrevs (name re) ...)" stx)]))
|
||||
|
||||
(define-syntax (define-lex-trans stx)
|
||||
(syntax-case stx ()
|
||||
[(_ name-form body-form)
|
||||
(let-values (((name body)
|
||||
(normalize-definition #'(define-syntax name-form body-form) #'λ)))
|
||||
|
||||
#`(define-syntax #,name
|
||||
(let ((func #,body))
|
||||
(unless (procedure? func)
|
||||
(raise-syntax-error 'define-lex-trans "expected a procedure as the transformer, got ~e" func))
|
||||
(unless (procedure-arity-includes? func 1)
|
||||
(raise-syntax-error 'define-lex-trans "expected a procedure that accepts 1 argument as the transformer, got ~e" func))
|
||||
(make-lex-trans func))))]
|
||||
[_
|
||||
(raise-syntax-error
|
||||
#f
|
||||
"form should be (define-lex-trans name transformer)"
|
||||
stx)]))
|
||||
|
||||
|
||||
(define (get-next-state-helper char min max table)
|
||||
(cond
|
||||
[(>= min max) #f]
|
||||
[else
|
||||
(define try (quotient (+ min max) 2))
|
||||
(define el (vector-ref table try))
|
||||
(define r1 (vector-ref el 0))
|
||||
(define r2 (vector-ref el 1))
|
||||
(cond
|
||||
[(and (>= char r1) (<= char r2)) (vector-ref el 2)]
|
||||
[(< char r1) (get-next-state-helper char min try table)]
|
||||
[else (get-next-state-helper char (add1 try) max table)])]))
|
||||
|
||||
|
||||
|
||||
|
||||
(define (get-next-state char table)
|
||||
(and table (get-next-state-helper char 0 (vector-length table) table)))
|
||||
|
||||
(define ((lexer-body start-state trans-table actions no-lookahead special-action
|
||||
has-special-comment-action? special-comment-action eof-action) ip)
|
||||
(define (lexer ip)
|
||||
(define first-pos (get-position ip))
|
||||
(define first-char (peek-char-or-special ip 0))
|
||||
;(printf "(peek-char-or-special port 0) = ~e\n" first-char)
|
||||
(cond
|
||||
[(eof-object? first-char)
|
||||
(do-match ip first-pos eof-action (read-char-or-special ip))]
|
||||
[(special-comment? first-char)
|
||||
(read-char-or-special ip)
|
||||
(cond
|
||||
(has-special-comment-action?
|
||||
(do-match ip first-pos special-comment-action #f))
|
||||
(else (lexer ip)))]
|
||||
[(not (char? first-char))
|
||||
(do-match ip first-pos special-action (read-char-or-special ip))]
|
||||
[else
|
||||
(let lexer-loop (
|
||||
;; current-state
|
||||
[state start-state]
|
||||
;; the character to transition on
|
||||
[char first-char]
|
||||
;; action for the longest match seen thus far
|
||||
;; including a match at the current state
|
||||
[longest-match-action
|
||||
(vector-ref actions start-state)]
|
||||
;; how many bytes precede char
|
||||
[length-bytes 0]
|
||||
;; how many characters have been read
|
||||
;; including the one just read
|
||||
[length-chars 1]
|
||||
;; how many characters are in the longest match
|
||||
[longest-match-length 0])
|
||||
(define next-state
|
||||
(cond
|
||||
[(not (char? char)) #f]
|
||||
[else (get-next-state (char->integer char)
|
||||
(vector-ref trans-table state))]))
|
||||
(cond
|
||||
[(not next-state)
|
||||
(check-match ip first-pos longest-match-length
|
||||
length-chars longest-match-action)]
|
||||
[(vector-ref no-lookahead next-state)
|
||||
(define act (vector-ref actions next-state))
|
||||
(check-match ip
|
||||
first-pos
|
||||
(if act length-chars longest-match-length)
|
||||
length-chars
|
||||
(if act act longest-match-action))]
|
||||
[else
|
||||
(define act (vector-ref actions next-state))
|
||||
(define next-length-bytes (+ (char-utf-8-length char) length-bytes))
|
||||
(define next-char (peek-char-or-special ip next-length-bytes))
|
||||
#;(printf "(peek-char-or-special port ~e) = ~e\n"
|
||||
next-length-bytes next-char)
|
||||
(lexer-loop next-state
|
||||
next-char
|
||||
(if act
|
||||
act
|
||||
longest-match-action)
|
||||
next-length-bytes
|
||||
(add1 length-chars)
|
||||
(if act
|
||||
length-chars
|
||||
longest-match-length))]))]))
|
||||
(unless (input-port? ip)
|
||||
(raise-argument-error 'lexer "input-port?" 0 ip))
|
||||
(lexer ip))
|
||||
|
||||
(define (check-match lb first-pos longest-match-length length longest-match-action)
|
||||
(unless longest-match-action
|
||||
(define match (read-string length lb))
|
||||
(define end-pos (get-position lb))
|
||||
(raise-read-error
|
||||
(format "lexer: No match found in input starting with: ~v" match)
|
||||
(file-path)
|
||||
(position-line first-pos)
|
||||
(position-col first-pos)
|
||||
(position-offset first-pos)
|
||||
(- (position-offset end-pos) (position-offset first-pos))))
|
||||
(define match (read-string longest-match-length lb))
|
||||
;(printf "(read-string ~e port) = ~e\n" longest-match-length match)
|
||||
(do-match lb first-pos longest-match-action match))
|
||||
|
||||
(define file-path (make-parameter #f))
|
||||
(define lexer-file-path file-path)
|
||||
|
||||
(define (do-match ip first-pos action value)
|
||||
#;(printf "(action ~a ~a ~a ~a)\n"
|
||||
(position-offset first-pos) (position-offset (get-position ip)) value ip)
|
||||
(action first-pos (get-position ip) value ip))
|
||||
|
||||
(define (get-position ip)
|
||||
(define-values (line col off) (port-next-location ip))
|
||||
(make-position off line col))
|
||||
|
||||
(define-syntax (create-unicode-abbrevs stx)
|
||||
(syntax-case stx ()
|
||||
[(_ CTXT)
|
||||
(with-syntax ([(RANGES ...) (for/list ([range (in-list (list (force alphabetic-ranges)
|
||||
(force lower-case-ranges)
|
||||
(force upper-case-ranges)
|
||||
(force title-case-ranges)
|
||||
(force numeric-ranges)
|
||||
(force symbolic-ranges)
|
||||
(force punctuation-ranges)
|
||||
(force graphic-ranges)
|
||||
(force whitespace-ranges)
|
||||
(force blank-ranges)
|
||||
(force iso-control-ranges)))])
|
||||
`(union ,@(map (λ (x)
|
||||
`(char-range ,(integer->char (car x))
|
||||
,(integer->char (cdr x))))
|
||||
range)))]
|
||||
[(NAMES ...) (for/list ([sym (in-list '(alphabetic
|
||||
lower-case
|
||||
upper-case
|
||||
title-case
|
||||
numeric
|
||||
symbolic
|
||||
punctuation
|
||||
graphic
|
||||
whitespace
|
||||
blank
|
||||
iso-control))])
|
||||
(datum->syntax #'CTXT sym #f))])
|
||||
#'(define-lex-abbrevs (NAMES RANGES) ...))]))
|
||||
|
||||
(define-lex-abbrev any-char (char-complement (union)))
|
||||
(define-lex-abbrev any-string (intersection))
|
||||
(define-lex-abbrev nothing (union))
|
||||
(create-unicode-abbrevs #'here)
|
||||
|
||||
(define-lex-trans (char-set stx)
|
||||
(syntax-case stx ()
|
||||
[(_ STR)
|
||||
(string? (syntax-e #'STR))
|
||||
(with-syntax ([(CHAR ...) (string->list (syntax-e #'STR))])
|
||||
#'(union CHAR ...))]))
|
||||
|
||||
(define-syntax provide-lex-keyword
|
||||
(syntax-rules ()
|
||||
[(_ ID ...)
|
||||
(begin
|
||||
(define-syntax-parameter ID
|
||||
(make-set!-transformer
|
||||
(λ (stx)
|
||||
(raise-syntax-error
|
||||
'provide-lex-keyword
|
||||
(format "use of a lexer keyword (~a) is not in an appropriate lexer action" 'ID)
|
||||
stx))))
|
||||
...
|
||||
(provide ID ...))]))
|
||||
|
||||
(provide-lex-keyword start-pos end-pos lexeme lexeme-srcloc input-port return-without-pos return-without-srcloc)
|
||||
@ -0,0 +1,15 @@
|
||||
#lang racket/base
|
||||
(provide (all-defined-out))
|
||||
(require syntax/stx)
|
||||
|
||||
;; get-special-action: (syntax-object list) syntax-object syntax-object -> syntax-object
|
||||
;; Returns the first action from a rule of the form ((which-special) action)
|
||||
(define (get-special-action rules which-special none)
|
||||
(cond
|
||||
[(null? rules) none]
|
||||
[else
|
||||
(syntax-case (car rules) ()
|
||||
[((special) ACT)
|
||||
(and (identifier? #'special) (module-or-top-identifier=? #'special which-special))
|
||||
#'ACT]
|
||||
[_ (get-special-action (cdr rules) which-special none)])]))
|
||||
@ -0,0 +1,333 @@
|
||||
#lang racket/base
|
||||
(require racket/list
|
||||
(prefix-in is: data/integer-set)
|
||||
"re.rkt"
|
||||
"util.rkt")
|
||||
|
||||
(provide build-dfa print-dfa (struct-out dfa))
|
||||
|
||||
(define e (build-epsilon))
|
||||
(define z (build-zero))
|
||||
|
||||
|
||||
;; Don't do anything with this one but extract the chars
|
||||
(define all-chars (->re `(char-complement (union)) (make-cache)))
|
||||
|
||||
;; get-char-groups : re bool -> (list-of char-setR?)
|
||||
;; Collects the char-setRs in r that could be used in
|
||||
;; taking the derivative of r.
|
||||
(define (get-char-groups r found-negation)
|
||||
(cond
|
||||
[(or (eq? r e) (eq? r z)) null]
|
||||
[(char-setR? r) (list r)]
|
||||
[(concatR? r)
|
||||
(if (re-nullable? (concatR-re1 r))
|
||||
(append (get-char-groups (concatR-re1 r) found-negation)
|
||||
(get-char-groups (concatR-re2 r) found-negation))
|
||||
(get-char-groups (concatR-re1 r) found-negation))]
|
||||
[(repeatR? r)
|
||||
(get-char-groups (repeatR-re r) found-negation)]
|
||||
[(orR? r)
|
||||
(apply append (map (λ (x) (get-char-groups x found-negation)) (orR-res r)))]
|
||||
[(andR? r)
|
||||
(apply append (map (λ (x) (get-char-groups x found-negation)) (andR-res r)))]
|
||||
[(negR? r)
|
||||
(if found-negation
|
||||
(get-char-groups (negR-re r) #t)
|
||||
(cons all-chars (get-char-groups (negR-re r) #t)))]))
|
||||
|
||||
(test-block ((c (make-cache))
|
||||
(r1 (->re #\1 c))
|
||||
(r2 (->re #\2 c)))
|
||||
((get-char-groups e #f) null)
|
||||
((get-char-groups z #f) null)
|
||||
((get-char-groups r1 #f) (list r1))
|
||||
((get-char-groups (->re `(concatenation ,r1 ,r2) c) #f)
|
||||
(list r1))
|
||||
((get-char-groups (->re `(concatenation ,e ,r2) c) #f)
|
||||
(list r2))
|
||||
((get-char-groups (->re `(concatenation (repetition 0 +inf.0 ,r1) ,r2) c) #f)
|
||||
(list r1 r2))
|
||||
((get-char-groups (->re `(repetition 0 +inf.0 ,r1) c) #f)
|
||||
(list r1))
|
||||
((get-char-groups
|
||||
(->re `(union (repetition 0 +inf.0 ,r1)
|
||||
(concatenation (repetition 0 +inf.0 ,r2) "3") "4") c) #f)
|
||||
(list r1 r2 (->re "3" c) (->re "4" c)))
|
||||
((get-char-groups (->re `(complement ,r1) c) #f)
|
||||
(list all-chars r1))
|
||||
((get-char-groups
|
||||
(->re `(intersection (repetition 0 +inf.0 ,r1)
|
||||
(concatenation (repetition 0 +inf.0 ,r2) "3") "4") c) #f)
|
||||
(list r1 r2 (->re "3" c) (->re "4" c)))
|
||||
)
|
||||
(define loc:member? is:member?)
|
||||
|
||||
;; deriveR : re char cache -> re
|
||||
(define (deriveR r c cache)
|
||||
(cond
|
||||
[(or (eq? r e) (eq? r z)) z]
|
||||
[(char-setR? r)
|
||||
(if (loc:member? c (char-setR-chars r)) e z)]
|
||||
[(concatR? r)
|
||||
(define r1 (concatR-re1 r))
|
||||
(define r2 (concatR-re2 r))
|
||||
(define d (build-concat (deriveR r1 c cache) r2 cache))
|
||||
(if (re-nullable? r1)
|
||||
(build-or (list d (deriveR r2 c cache)) cache)
|
||||
d)]
|
||||
[(repeatR? r)
|
||||
(build-concat (deriveR (repeatR-re r) c cache)
|
||||
(build-repeat (sub1 (repeatR-low r))
|
||||
(sub1 (repeatR-high r))
|
||||
(repeatR-re r) cache)
|
||||
cache)]
|
||||
[(orR? r)
|
||||
(build-or (map (λ (x) (deriveR x c cache))
|
||||
(orR-res r))
|
||||
cache)]
|
||||
[(andR? r)
|
||||
(build-and (map (λ (x) (deriveR x c cache))
|
||||
(andR-res r))
|
||||
cache)]
|
||||
[(negR? r)
|
||||
(build-neg (deriveR (negR-re r) c cache) cache)]))
|
||||
|
||||
(test-block ((c (make-cache))
|
||||
(a (char->integer #\a))
|
||||
(b (char->integer #\b))
|
||||
(r1 (->re #\a c))
|
||||
(r2 (->re `(repetition 0 +inf.0 #\a) c))
|
||||
(r3 (->re `(repetition 0 +inf.0 ,r2) c))
|
||||
(r4 (->re `(concatenation #\a ,r2) c))
|
||||
(r5 (->re `(repetition 0 +inf.0 ,r4) c))
|
||||
(r6 (->re `(union ,r5 #\a) c))
|
||||
(r7 (->re `(concatenation ,r2 ,r2) c))
|
||||
(r8 (->re `(complement ,r4) c))
|
||||
(r9 (->re `(intersection ,r2 ,r4) c)))
|
||||
((deriveR e a c) z)
|
||||
((deriveR z a c) z)
|
||||
((deriveR r1 b c) z)
|
||||
((deriveR r1 a c) e)
|
||||
((deriveR r2 a c) r2)
|
||||
((deriveR r2 b c) z)
|
||||
((deriveR r3 a c) r2)
|
||||
((deriveR r3 b c) z)
|
||||
((deriveR r4 a c) r2)
|
||||
((deriveR r4 b c) z)
|
||||
((deriveR r5 a c) (->re `(concatenation ,r2 ,r5) c))
|
||||
((deriveR r5 b c) z)
|
||||
((deriveR r6 a c) (->re `(union (concatenation ,r2 ,r5) "") c))
|
||||
((deriveR r6 b c) z)
|
||||
((deriveR r7 a c) (->re `(union (concatenation ,r2 ,r2) ,r2) c))
|
||||
((deriveR r7 b c) z)
|
||||
((deriveR r8 a c) (->re `(complement, r2) c))
|
||||
((deriveR r8 b c) (->re `(complement ,z) c))
|
||||
((deriveR r9 a c) r2)
|
||||
((deriveR r9 b c) z)
|
||||
((deriveR (->re `(repetition 1 2 "ab") c) a c)
|
||||
(->re `(concatenation "b" (repetition 0 1 "ab")) c)))
|
||||
|
||||
;; An re-action is (cons re action)
|
||||
|
||||
;; derive : (list-of re-action) char cache -> (union (list-of re-action) #f)
|
||||
;; applies deriveR to all the re-actions's re parts.
|
||||
;; Returns #f if the derived state is equivalent to z.
|
||||
(define (derive r c cache)
|
||||
(define new-r (for/list ([ra (in-list r)])
|
||||
(cons (deriveR (car ra) c cache) (cdr ra))))
|
||||
(if (andmap (λ (x) (eq? z (car x))) new-r)
|
||||
#f
|
||||
new-r))
|
||||
|
||||
(test-block ((c (make-cache))
|
||||
(r1 (->re #\1 c))
|
||||
(r2 (->re #\2 c)))
|
||||
((derive null (char->integer #\1) c) #f)
|
||||
((derive (list (cons r1 1) (cons r2 2)) (char->integer #\1) c)
|
||||
(list (cons e 1) (cons z 2)))
|
||||
((derive (list (cons r1 1) (cons r2 2)) (char->integer #\3) c) #f))
|
||||
|
||||
|
||||
;; get-final : (list-of re-action) -> (union #f syntax-object)
|
||||
;; An re that accepts e represents a final state. Return the
|
||||
;; action from the first final state or #f if there is none.
|
||||
(define (get-final res)
|
||||
(cond
|
||||
[(null? res) #f]
|
||||
[(re-nullable? (caar res)) (cdar res)]
|
||||
[else (get-final (cdr res))]))
|
||||
|
||||
(test-block ((c->i char->integer)
|
||||
(c (make-cache))
|
||||
(r1 (->re #\a c))
|
||||
(r2 (->re #\b c))
|
||||
(b (list (cons z 1) (cons z 2) (cons z 3) (cons e 4) (cons z 5)))
|
||||
(a (list (cons r1 1) (cons r2 2))))
|
||||
((derive null (c->i #\a) c) #f)
|
||||
((derive a (c->i #\a) c) (list (cons e 1) (cons z 2)))
|
||||
((derive a (c->i #\b) c) (list (cons z 1) (cons e 2)))
|
||||
((derive a (c->i #\c) c) #f)
|
||||
((derive (list (cons (->re `(union " " "\n" ",") c) 1)
|
||||
(cons (->re `(concatenation (repetition 0 1 "-")
|
||||
(repetition 1 +inf.0 (char-range "0" "9"))) c) 2)
|
||||
(cons (->re `(concatenation "-" (repetition 1 +inf.0 "-")) c) 3)
|
||||
(cons (->re "[" c) 4)
|
||||
(cons (->re "]" c) 5)) (c->i #\[) c)
|
||||
b)
|
||||
((get-final a) #f)
|
||||
((get-final (list (cons e 1) (cons e 2))) 1)
|
||||
((get-final b) 4))
|
||||
|
||||
|
||||
;; A state is (make-state (list-of re-action) nat)
|
||||
(define-struct state (spec index))
|
||||
|
||||
;; get->key : re-action -> (list-of nat)
|
||||
;; states are indexed by the list of indexes of their res
|
||||
(define (get-key s)
|
||||
(map (λ (x) (re-index (car x))) s))
|
||||
|
||||
(define loc:partition is:partition)
|
||||
|
||||
;; compute-chars : (list-of state) -> (list-of char-set)
|
||||
;; Computed the sets of equivalent characters for taking the
|
||||
;; derivative of the car of st. Only one derivative per set need to be taken.
|
||||
(define (compute-chars st)
|
||||
(cond
|
||||
[(null? st) null]
|
||||
[else
|
||||
(loc:partition (map char-setR-chars
|
||||
(apply append (map (λ (x) (get-char-groups (car x) #f))
|
||||
(state-spec (car st))))))]))
|
||||
|
||||
(test-block ((c (make-cache))
|
||||
(c->i char->integer)
|
||||
(r1 (->re `(char-range #\1 #\4) c))
|
||||
(r2 (->re `(char-range #\2 #\3) c)))
|
||||
((compute-chars null) null)
|
||||
((compute-chars (list (make-state null 1))) null)
|
||||
((map is:integer-set-contents
|
||||
(compute-chars (list (make-state (list (cons r1 1) (cons r2 2)) 2))))
|
||||
(list (is:integer-set-contents (is:make-range (c->i #\2) (c->i #\3)))
|
||||
(is:integer-set-contents (is:union (is:make-range (c->i #\1))
|
||||
(is:make-range (c->i #\4)))))))
|
||||
|
||||
|
||||
;; A dfa is (make-dfa int int
|
||||
;; (list-of (cons int syntax-object))
|
||||
;; (list-of (cons int (list-of (cons char-set int)))))
|
||||
;; Each transitions is a state and a list of chars with the state to transition to.
|
||||
;; The finals and transitions are sorted by state number, and duplicate free.
|
||||
(define-struct dfa (num-states start-state final-states/actions transitions) #:inspector (make-inspector))
|
||||
|
||||
(define loc:get-integer is:get-integer)
|
||||
|
||||
;; build-dfa : (list-of re-action) cache -> dfa
|
||||
(define (build-dfa rs cache)
|
||||
(let* ([transitions (make-hash)]
|
||||
[get-state-number (make-counter)]
|
||||
[start (make-state rs (get-state-number))])
|
||||
(cache (cons 'state (get-key rs)) (λ () start))
|
||||
(let loop ([old-states (list start)]
|
||||
[new-states null]
|
||||
[all-states (list start)]
|
||||
[cs (compute-chars (list start))])
|
||||
(cond
|
||||
[(and (null? old-states) (null? new-states))
|
||||
(make-dfa (get-state-number) (state-index start)
|
||||
(sort (for*/list ([state (in-list all-states)]
|
||||
[val (in-value (cons (state-index state) (get-final (state-spec state))))]
|
||||
#:when (cdr val))
|
||||
val)
|
||||
< #:key car)
|
||||
(sort (hash-map transitions
|
||||
(λ (state trans)
|
||||
(cons (state-index state)
|
||||
(for/list ([t (in-list trans)])
|
||||
(cons (car t)
|
||||
(state-index (cdr t)))))))
|
||||
< #:key car))]
|
||||
[(null? old-states)
|
||||
(loop new-states null all-states (compute-chars new-states))]
|
||||
[(null? cs)
|
||||
(loop (cdr old-states) new-states all-states (compute-chars (cdr old-states)))]
|
||||
[else
|
||||
(define state (car old-states))
|
||||
(define c (car cs))
|
||||
(define new-re (derive (state-spec state) (loc:get-integer c) cache))
|
||||
(cond
|
||||
[new-re
|
||||
(let* ([new-state? #f]
|
||||
[new-state (cache (cons 'state (get-key new-re))
|
||||
(λ ()
|
||||
(set! new-state? #t)
|
||||
(make-state new-re (get-state-number))))]
|
||||
[new-all-states (if new-state? (cons new-state all-states) all-states)])
|
||||
(hash-set! transitions
|
||||
state
|
||||
(cons (cons c new-state)
|
||||
(hash-ref transitions state
|
||||
(λ () null))))
|
||||
(cond
|
||||
[new-state?
|
||||
(loop old-states (cons new-state new-states) new-all-states (cdr cs))]
|
||||
[else
|
||||
(loop old-states new-states new-all-states (cdr cs))]))]
|
||||
[else (loop old-states new-states all-states (cdr cs))])]))))
|
||||
|
||||
(define (print-dfa x)
|
||||
(printf "number of states: ~a\n" (dfa-num-states x))
|
||||
(printf "start state: ~a\n" (dfa-start-state x))
|
||||
(printf "final states: ~a\n" (map car (dfa-final-states/actions x)))
|
||||
(for-each (λ (trans)
|
||||
(printf "state: ~a\n" (car trans))
|
||||
(for-each (λ (rule)
|
||||
(printf " -~a-> ~a\n"
|
||||
(is:integer-set-contents (car rule))
|
||||
(cdr rule)))
|
||||
(cdr trans)))
|
||||
(dfa-transitions x)))
|
||||
|
||||
(define (build-test-dfa rs)
|
||||
(define c (make-cache))
|
||||
(build-dfa (map (λ (x) (cons (->re x c) 'action)) rs) c))
|
||||
|
||||
|
||||
#|
|
||||
(define t1 (build-test-dfa null))
|
||||
(define t2 (build-test-dfa `(#\a)))
|
||||
(define t3 (build-test-dfa `(#\a #\b)))
|
||||
(define t4 (build-test-dfa `((repetition 0 +inf.0 #\a)
|
||||
(repetition 0 +inf.0 (concatenation #\a #\b)))))
|
||||
(define t5 (build-test-dfa `((concatenation (repetition 0 +inf.0 (union #\0 #\1)) #\1))))
|
||||
(define t6 (build-test-dfa `((repetition 0 +inf.0 (repetition 0 +inf.0 #\a))
|
||||
(repetition 0 +inf.0 (concatenation #\b (repetition 1 +inf.0 #\b))))))
|
||||
(define t7 (build-test-dfa `((concatenation (repetition 0 +inf.0 #\a) (repetition 0 +inf.0 #\b)
|
||||
(repetition 0 +inf.0 #\c) (repetition 0 +inf.0 #\d)
|
||||
(repetition 0 +inf.0 #\e)))))
|
||||
(define t8
|
||||
(build-test-dfa `((concatenation (repetition 0 +inf.0 (union #\a #\b)) #\a (union #\a #\b)
|
||||
(union #\a #\b) (union #\a #\b) (union #\a #\b)))))
|
||||
(define t9 (build-test-dfa `((concatenation "/*"
|
||||
(complement (concatenation (intersection) "*/" (intersection)))
|
||||
"*/"))))
|
||||
(define t11 (build-test-dfa `((complement "1"))))
|
||||
(define t12 (build-test-dfa `((concatenation (intersection (concatenation (repetition 0 +inf.0 "a") "b")
|
||||
(concatenation "a" (repetition 0 +inf.0 "b")))
|
||||
"ab"))))
|
||||
(define x (build-test-dfa `((union " " "\n" ",")
|
||||
(concatenation (repetition 0 1 "-") (repetition 1 +inf.0 (char-range "0" "9")))
|
||||
(concatenation "-" (repetition 1 +inf.0 "-"))
|
||||
"["
|
||||
"]")))
|
||||
(define y (build-test-dfa
|
||||
`((repetition 1 +inf.0
|
||||
(union (concatenation "|" (repetition 0 +inf.0 (char-complement "|")) "|")
|
||||
(concatenation "|" (repetition 0 +inf.0 (char-complement "|"))))))))
|
||||
(define t13 (build-test-dfa `((intersection (concatenation (intersection) "111" (intersection))
|
||||
(complement (union (concatenation (intersection) "01")
|
||||
(repetition 1 +inf.0 "1")))))))
|
||||
(define t14 (build-test-dfa `((complement "1")))))
|
||||
|
||||
|#
|
||||
@ -0,0 +1,81 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base)
|
||||
"../lex.rkt"
|
||||
rackunit)
|
||||
|
||||
(define-syntax (catch-syn-error stx)
|
||||
(syntax-case stx ()
|
||||
[(_ arg)
|
||||
(datum->syntax
|
||||
#'here
|
||||
(with-handlers ((exn:fail:syntax? exn-message))
|
||||
(syntax-local-expand-expression #'arg)
|
||||
"not-an-error"))]))
|
||||
|
||||
(check-regexp-match #rx"lex-abbrev" (catch-syn-error (define-lex-abbrev)))
|
||||
(check-regexp-match #rx"lex-abbrev" (catch-syn-error (define-lex-abbrev a)))
|
||||
(check-regexp-match #rx"lex-abbrev" (catch-syn-error (define-lex-abbrev (a b) v)))
|
||||
(check-regexp-match #rx"lex-abbrev" (catch-syn-error (define-lex-abbrev 1 1)))
|
||||
(check-regexp-match #rx"lex-abbrevs" (catch-syn-error (define-lex-abbrevs ())))
|
||||
|
||||
(check-regexp-match #rx"lex-trans" (catch-syn-error (define-lex-trans)))
|
||||
|
||||
(check-regexp-match #rx"lexer" (catch-syn-error (lexer)))
|
||||
(check-regexp-match #rx"lexer" (catch-syn-error (lexer ("a" "b" "c"))))
|
||||
(check-regexp-match #rx"lexer" (catch-syn-error (lexer ())))
|
||||
(check-regexp-match #rx"lexer" (catch-syn-error (lexer (""))))
|
||||
|
||||
(check-regexp-match #rx"regular-expression" (catch-syn-error (lexer (a 1))))
|
||||
(check-regexp-match #rx"regular-expression" (catch-syn-error (lexer ((a) 1))))
|
||||
(check-regexp-match #rx"regular-expression" (catch-syn-error (let ((a 1)) (lexer ((a) 1)))))
|
||||
|
||||
(check-regexp-match #rx"regular-expression"
|
||||
(catch-syn-error (let-syntax ((a 1))
|
||||
(lexer ((a) 1)))))
|
||||
|
||||
(check-regexp-match #rx"define-lex-trans"
|
||||
(catch-syn-error
|
||||
(let ()
|
||||
(define-lex-trans a 1)
|
||||
(let ()
|
||||
(lexer ((a) 1))))))
|
||||
|
||||
;; Detecting mutual recursion cycle:
|
||||
(check-regexp-match #rx"regular-expression"
|
||||
(catch-syn-error
|
||||
(let ()
|
||||
(define-lex-abbrev a b)
|
||||
(define-lex-abbrev b a)
|
||||
(let ()
|
||||
(lexer (a 1))))))
|
||||
|
||||
(check-regexp-match #rx"regular-expression"
|
||||
(catch-syn-error
|
||||
(let ()
|
||||
(define-lex-abbrev a (repetition 0 1 b))
|
||||
(define-lex-abbrev b (repetition 0 1 a))
|
||||
(let ()
|
||||
(lexer (a 1))))))
|
||||
|
||||
;; Detecting cycle within same abbreviation:
|
||||
(check-regexp-match #rx"regular-expression"
|
||||
(catch-syn-error
|
||||
(let ()
|
||||
(define-lex-abbrev balanced
|
||||
(union (concatenation "(" balanced ")" balanced)
|
||||
any-char))
|
||||
(lexer
|
||||
[balanced (string-append lexeme (balanced input-port))]
|
||||
[(eof) ""]))))
|
||||
|
||||
|
||||
(check-regexp-match #rx"regular-expression" (catch-syn-error (lexer (1 1))))
|
||||
(check-regexp-match #rx"repetition" (catch-syn-error (lexer ((repetition) 1))))
|
||||
(check-regexp-match #rx"repetition" (catch-syn-error (lexer ((repetition #\1 #\1 "3") 1))))
|
||||
(check-regexp-match #rx"repetition" (catch-syn-error (lexer ((repetition 1 #\1 "3") 1))))
|
||||
(check-regexp-match #rx"repetition" (catch-syn-error (lexer ((repetition 1 0 "3") 1))))
|
||||
(check-regexp-match #rx"complement" (catch-syn-error (lexer ((complement) 1))))
|
||||
(check-regexp-match #rx"char-range" (catch-syn-error (lexer ((char-range) 1))))
|
||||
(check-regexp-match #rx"char-range" (catch-syn-error (lexer ((char-range #\9 #\0) 1))))
|
||||
(check-regexp-match #rx"char-complement" (catch-syn-error (lexer ((char-complement) 1))))
|
||||
(check-regexp-match #rx"char-complement" (catch-syn-error (lexer ((char-complement (concatenation "1" "2")) 1))))
|
||||
@ -0,0 +1,159 @@
|
||||
#lang racket/base
|
||||
(require racket/base
|
||||
racket/match
|
||||
(prefix-in is: data/integer-set)
|
||||
racket/list
|
||||
syntax/stx
|
||||
"util.rkt"
|
||||
"stx.rkt"
|
||||
"re.rkt"
|
||||
"deriv.rkt")
|
||||
|
||||
(provide build-lexer)
|
||||
|
||||
(define-syntax time-label
|
||||
(syntax-rules ()
|
||||
((_ l e ...)
|
||||
(begin
|
||||
(printf "~a: " l)
|
||||
(time (begin e ...))))))
|
||||
|
||||
;; A table is either
|
||||
;; - (vector-of (union #f nat))
|
||||
;; - (vector-of (vector-of (vector nat nat nat)))
|
||||
|
||||
(define loc:integer-set-contents is:integer-set-contents)
|
||||
|
||||
;; dfa->1d-table : dfa -> (same as build-lexer)
|
||||
(define (dfa->1d-table dfa)
|
||||
(define state-table (make-vector (dfa-num-states dfa) #f))
|
||||
(define transition-cache (make-hasheq))
|
||||
(for ([trans (in-list (dfa-transitions dfa))])
|
||||
(match-define (cons from-state all-chars/to) trans)
|
||||
(define flat-all-chars/to
|
||||
(sort
|
||||
(for*/list ([chars/to (in-list all-chars/to)]
|
||||
[char-ranges (in-value (loc:integer-set-contents (car chars/to)))]
|
||||
[to (in-value (cdr chars/to))]
|
||||
[char-range (in-list char-ranges)])
|
||||
(define entry (vector (car char-range) (cdr char-range) to))
|
||||
(hash-ref transition-cache entry (λ ()
|
||||
(hash-set! transition-cache
|
||||
entry
|
||||
entry)
|
||||
entry)))
|
||||
< #:key (λ (v) (vector-ref v 0))))
|
||||
(vector-set! state-table from-state (list->vector flat-all-chars/to)))
|
||||
state-table)
|
||||
|
||||
|
||||
(define loc:foldr is:foldr)
|
||||
|
||||
;; dfa->2d-table : dfa -> (same as build-lexer)
|
||||
(define (dfa->2d-table dfa)
|
||||
;; char-table : (vector-of (union #f nat))
|
||||
;; The lexer table, one entry per state per char.
|
||||
;; Each entry specifies a state to transition to.
|
||||
;; #f indicates no transition
|
||||
(define char-table (make-vector (* 256 (dfa-num-states dfa)) #f))
|
||||
;; Fill the char-table vector
|
||||
(for* ([trans (in-list (dfa-transitions dfa))]
|
||||
[chars/to (in-list (cdr trans))])
|
||||
(define from-state (car trans))
|
||||
(define to-state (cdr chars/to))
|
||||
(loc:foldr (λ (char _)
|
||||
(vector-set! char-table
|
||||
(bitwise-ior
|
||||
char
|
||||
(arithmetic-shift from-state 8))
|
||||
to-state))
|
||||
(void)
|
||||
(car chars/to)))
|
||||
char-table)
|
||||
|
||||
|
||||
;; dfa->actions : dfa -> (vector-of (union #f syntax-object))
|
||||
;; The action for each final state, #f if the state isn't final
|
||||
(define (dfa->actions dfa)
|
||||
(define actions (make-vector (dfa-num-states dfa) #f))
|
||||
(for ([state/action (in-list (dfa-final-states/actions dfa))])
|
||||
(vector-set! actions (car state/action) (cdr state/action)))
|
||||
actions)
|
||||
|
||||
;; dfa->no-look : dfa -> (vector-of bool)
|
||||
;; For each state whether the lexer can ignore the next input.
|
||||
;; It can do this only if there are no transitions out of the
|
||||
;; current state.
|
||||
(define (dfa->no-look dfa)
|
||||
(define no-look (make-vector (dfa-num-states dfa) #t))
|
||||
(for ([trans (in-list (dfa-transitions dfa))])
|
||||
(vector-set! no-look (car trans) #f))
|
||||
no-look)
|
||||
|
||||
(test-block ((d1 (make-dfa 1 1 (list) (list)))
|
||||
(d2 (make-dfa 4 1 (list (cons 2 2) (cons 3 3))
|
||||
(list (cons 1 (list (cons (is:make-range 49 50) 1)
|
||||
(cons (is:make-range 51) 2)))
|
||||
(cons 2 (list (cons (is:make-range 49) 3))))))
|
||||
(d3 (make-dfa 4 1 (list (cons 2 2) (cons 3 3))
|
||||
(list (cons 1 (list (cons (is:make-range 100 200) 0)
|
||||
(cons (is:make-range 49 50) 1)
|
||||
(cons (is:make-range 51) 2)))
|
||||
(cons 2 (list (cons (is:make-range 49) 3)))))))
|
||||
((dfa->2d-table d1) (make-vector 256 #f))
|
||||
((dfa->2d-table d2) (let ((v (make-vector 1024 #f)))
|
||||
(vector-set! v 305 1)
|
||||
(vector-set! v 306 1)
|
||||
(vector-set! v 307 2)
|
||||
(vector-set! v 561 3)
|
||||
v))
|
||||
((dfa->1d-table d1) (make-vector 1 #f))
|
||||
((dfa->1d-table d2) #(#f
|
||||
#(#(49 50 1) #(51 51 2))
|
||||
#(#(49 49 3))
|
||||
#f))
|
||||
((dfa->1d-table d3) #(#f
|
||||
#(#(49 50 1) #(51 51 2) #(100 200 0))
|
||||
#(#(49 49 3))
|
||||
#f))
|
||||
((dfa->actions d1) (vector #f))
|
||||
((dfa->actions d2) (vector #f #f 2 3))
|
||||
((dfa->no-look d1) (vector #t))
|
||||
((dfa->no-look d2) (vector #t #f #f #t)))
|
||||
|
||||
;; build-lexer : syntax-object list ->
|
||||
;; (values table nat (vector-of (union #f syntax-object)) (vector-of bool) (list-of syntax-object))
|
||||
;; each syntax object has the form (re action)
|
||||
(define (build-lexer sos)
|
||||
(define s-re-acts (for/list ([so (in-list sos)])
|
||||
(cons (parse (stx-car so))
|
||||
(stx-car (stx-cdr so)))))
|
||||
(define cache (make-cache))
|
||||
(define re-acts (for/list ([s-re-act (in-list s-re-acts)])
|
||||
(cons (->re (car s-re-act) cache)
|
||||
(cdr s-re-act))))
|
||||
(define dfa (build-dfa re-acts cache))
|
||||
(define table (dfa->1d-table dfa))
|
||||
;(print-dfa dfa)
|
||||
#;(let ((num-states (vector-length table))
|
||||
(num-vectors (length (filter values (vector->list table))))
|
||||
(num-entries (apply + (map
|
||||
(λ (x) (if x (vector-length x) 0))
|
||||
(vector->list table))))
|
||||
(num-different-entries
|
||||
(let ((ht (make-hash)))
|
||||
(for-each
|
||||
(λ (x)
|
||||
(when x
|
||||
(for-each
|
||||
(λ (y)
|
||||
(hash-set! ht y #t))
|
||||
(vector->list x))))
|
||||
(vector->list table))
|
||||
(length (hash-table-map ht cons)))))
|
||||
(printf "~a states, ~aKB\n"
|
||||
num-states
|
||||
(/ (* 4.0 (+ 2 num-states (* 2 num-vectors) num-entries
|
||||
(* 5 num-different-entries))) 1024)))
|
||||
(values table (dfa-start-state dfa) (dfa->actions dfa) (dfa->no-look dfa)))
|
||||
|
||||
@ -0,0 +1,384 @@
|
||||
#lang racket/base
|
||||
(require racket/list
|
||||
racket/match
|
||||
(prefix-in is: data/integer-set)
|
||||
"util.rkt")
|
||||
|
||||
(provide ->re build-epsilon build-zero build-char-set build-concat
|
||||
build-repeat build-or build-and build-neg
|
||||
epsilonR? zeroR? char-setR? concatR? repeatR? orR? andR? negR?
|
||||
char-setR-chars concatR-re1 concatR-re2 repeatR-re repeatR-low repeatR-high
|
||||
orR-res andR-res negR-re
|
||||
re-nullable? re-index)
|
||||
|
||||
;; get-index : -> nat
|
||||
(define get-index (make-counter))
|
||||
|
||||
;; An re is either
|
||||
;; - (make-epsilonR bool nat)
|
||||
;; - (make-zeroR bool nat)
|
||||
;; - (make-char-setR bool nat char-set)
|
||||
;; - (make-concatR bool nat re re)
|
||||
;; - (make-repeatR bool nat nat nat-or-+inf.0 re)
|
||||
;; - (make-orR bool nat (list-of re)) Must not directly contain any orRs
|
||||
;; - (make-andR bool nat (list-of re)) Must not directly contain any andRs
|
||||
;; - (make-negR bool nat re)
|
||||
;;
|
||||
;; Every re must have an index field globally different from all
|
||||
;; other re index fields.
|
||||
(define-struct re (nullable? index) #:inspector (make-inspector))
|
||||
(define-struct (epsilonR re) () #:inspector (make-inspector))
|
||||
(define-struct (zeroR re) () #:inspector (make-inspector))
|
||||
(define-struct (char-setR re) (chars) #:inspector (make-inspector))
|
||||
(define-struct (concatR re) (re1 re2) #:inspector (make-inspector))
|
||||
(define-struct (repeatR re) (low high re) #:inspector (make-inspector))
|
||||
(define-struct (orR re) (res) #:inspector (make-inspector))
|
||||
(define-struct (andR re) (res) #:inspector (make-inspector))
|
||||
(define-struct (negR re) (re) #:inspector (make-inspector))
|
||||
|
||||
;; e : re
|
||||
;; The unique epsilon re
|
||||
(define e (make-epsilonR #t (get-index)))
|
||||
|
||||
;; z : re
|
||||
;; The unique zero re
|
||||
(define z (make-zeroR #f (get-index)))
|
||||
|
||||
|
||||
;; s-re = char constant
|
||||
;; | string constant (sequence of characters)
|
||||
;; | re a precompiled re
|
||||
;; | (repetition low high s-re) repetition between low and high times (inclusive)
|
||||
;; | (union s-re ...)
|
||||
;; | (intersection s-re ...)
|
||||
;; | (complement s-re)
|
||||
;; | (concatenation s-re ...)
|
||||
;; | (char-range rng rng) match any character between two (inclusive)
|
||||
;; | (char-complement char-set) match any character not listed
|
||||
;; low = natural-number
|
||||
;; high = natural-number or +inf.0
|
||||
;; rng = char or string with length 1
|
||||
;; (concatenation) (repetition 0 0 x), and "" match the empty string.
|
||||
;; (union) matches no strings.
|
||||
;; (intersection) matches any string.
|
||||
|
||||
(define loc:make-range is:make-range)
|
||||
(define loc:union is:union)
|
||||
(define loc:split is:split)
|
||||
(define loc:complement is:complement)
|
||||
|
||||
;; ->re : s-re cache -> re
|
||||
(define (->re exp cache)
|
||||
(match exp
|
||||
[(? char?) (build-char-set (loc:make-range (char->integer exp)) cache)]
|
||||
[(? string?) (->re `(concatenation ,@(string->list exp)) cache)]
|
||||
[(? re?) exp]
|
||||
[`(repetition ,low ,high ,r)
|
||||
(build-repeat low high (->re r cache) cache)]
|
||||
[`(union ,rs ...)
|
||||
(build-or (flatten-res (map (λ (r) (->re r cache)) rs)
|
||||
orR? orR-res loc:union cache)
|
||||
cache)]
|
||||
[`(intersection ,rs ...)
|
||||
(build-and (flatten-res (map (λ (r) (->re r cache)) rs)
|
||||
andR? andR-res (λ (a b)
|
||||
(let-values (((i _ __) (loc:split a b))) i))
|
||||
cache)
|
||||
cache)]
|
||||
[`(complement ,r) (build-neg (->re r cache) cache)]
|
||||
[`(concatenation ,rs ...)
|
||||
(foldr (λ (x y)
|
||||
(build-concat (->re x cache) y cache))
|
||||
e
|
||||
rs)]
|
||||
[`(char-range ,c1 ,c2)
|
||||
(let ([i1 (char->integer (if (string? c1) (string-ref c1 0) c1))]
|
||||
[i2 (char->integer (if (string? c2) (string-ref c2 0) c2))])
|
||||
(if (<= i1 i2)
|
||||
(build-char-set (loc:make-range i1 i2) cache)
|
||||
z))]
|
||||
[`(char-complement ,crs ...)
|
||||
(let ([cs (->re `(union ,@crs) cache)])
|
||||
(cond
|
||||
[(zeroR? cs) (build-char-set (loc:make-range 0 max-char-num) cache)]
|
||||
[(char-setR? cs)
|
||||
(build-char-set (loc:complement (char-setR-chars cs) 0 max-char-num) cache)]
|
||||
[else z]))]))
|
||||
|
||||
|
||||
|
||||
|
||||
;; flatten-res: (list-of re) (re -> bool) (re -> (list-of re))
|
||||
;; (char-set char-set -> char-set) cache -> (list-of re)
|
||||
;; Takes all the char-sets in l and combines them into one char-set using the combine function.
|
||||
;; Flattens out the values of type?. get-res only needs to function on things type? returns
|
||||
;; true for.
|
||||
(define (flatten-res l type? get-res combine cache)
|
||||
(let loop ([res l]
|
||||
;; chars : (union #f char-set)
|
||||
[chars #f]
|
||||
[no-chars null])
|
||||
(cond
|
||||
[(null? res)
|
||||
(if chars
|
||||
(cons (build-char-set chars cache) no-chars)
|
||||
no-chars)]
|
||||
[(char-setR? (car res))
|
||||
(if chars
|
||||
(loop (cdr res) (combine (char-setR-chars (car res)) chars) no-chars)
|
||||
(loop (cdr res) (char-setR-chars (car res)) no-chars))]
|
||||
[(type? (car res))
|
||||
(loop (append (get-res (car res)) (cdr res)) chars no-chars)]
|
||||
[else (loop (cdr res) chars (cons (car res) no-chars))])))
|
||||
|
||||
;; build-epsilon : -> re
|
||||
(define (build-epsilon) e)
|
||||
|
||||
(define (build-zero) z)
|
||||
|
||||
(define loc:integer-set-contents is:integer-set-contents)
|
||||
|
||||
;; build-char-set : char-set cache -> re
|
||||
(define (build-char-set cs cache)
|
||||
(define l (loc:integer-set-contents cs))
|
||||
(cond
|
||||
[(null? l) z]
|
||||
[else
|
||||
(cache l
|
||||
(λ ()
|
||||
(make-char-setR #f (get-index) cs)))]))
|
||||
|
||||
|
||||
|
||||
;; build-concat : re re cache -> re
|
||||
(define (build-concat r1 r2 cache)
|
||||
(cond
|
||||
[(eq? e r1) r2]
|
||||
[(eq? e r2) r1]
|
||||
[(or (eq? z r1) (eq? z r2)) z]
|
||||
[else
|
||||
(cache (cons 'concat (cons (re-index r1) (re-index r2)))
|
||||
(λ ()
|
||||
(make-concatR (and (re-nullable? r1) (re-nullable? r2))
|
||||
(get-index)
|
||||
r1 r2)))]))
|
||||
|
||||
;; build-repeat : nat nat-or-+inf.0 re cache -> re
|
||||
(define (build-repeat low high r cache)
|
||||
(let ([low (if (< low 0) 0 low)])
|
||||
(cond
|
||||
[(eq? r e) e]
|
||||
[(and (= 0 low) (or (= 0 high) (eq? z r))) e]
|
||||
[(and (= 1 low) (= 1 high)) r]
|
||||
[(and (repeatR? r)
|
||||
(eqv? (repeatR-high r) +inf.0)
|
||||
(or (= 0 (repeatR-low r))
|
||||
(= 1 (repeatR-low r))))
|
||||
(build-repeat (* low (repeatR-low r))
|
||||
+inf.0
|
||||
(repeatR-re r)
|
||||
cache)]
|
||||
[else
|
||||
(cache (cons 'repeat (cons low (cons high (re-index r))))
|
||||
(λ ()
|
||||
(make-repeatR (or (re-nullable? r) (= 0 low)) (get-index) low high r)))])))
|
||||
|
||||
|
||||
;; build-or : (list-of re) cache -> re
|
||||
(define (build-or rs cache)
|
||||
(let ([rs
|
||||
(filter
|
||||
(λ (x) (not (eq? x z)))
|
||||
(do-simple-equiv (replace rs orR? orR-res null) re-index))])
|
||||
(cond
|
||||
[(null? rs) z]
|
||||
[(null? (cdr rs)) (car rs)]
|
||||
[(memq (build-neg z cache) rs) (build-neg z cache)]
|
||||
[else
|
||||
(cache (cons 'or (map re-index rs))
|
||||
(λ ()
|
||||
(make-orR (ormap re-nullable? rs) (get-index) rs)))])))
|
||||
|
||||
;; build-and : (list-of re) cache -> re
|
||||
(define (build-and rs cache)
|
||||
(let ([rs (do-simple-equiv (replace rs andR? andR-res null) re-index)])
|
||||
(cond
|
||||
[(null? rs) (build-neg z cache)]
|
||||
[(null? (cdr rs)) (car rs)]
|
||||
[(memq z rs) z]
|
||||
[else
|
||||
(cache (cons 'and (map re-index rs))
|
||||
(λ ()
|
||||
(make-andR (andmap re-nullable? rs) (get-index) rs)))])))
|
||||
|
||||
;; build-neg : re cache -> re
|
||||
(define (build-neg r cache)
|
||||
(cond
|
||||
[(negR? r) (negR-re r)]
|
||||
[else
|
||||
(cache (cons 'neg (re-index r))
|
||||
(λ ()
|
||||
(make-negR (not (re-nullable? r)) (get-index) r)))]))
|
||||
|
||||
;; Tests for the build-functions
|
||||
(test-block ((c (make-cache))
|
||||
(isc is:integer-set-contents)
|
||||
(r1 (build-char-set (is:make-range (char->integer #\1)) c))
|
||||
(r2 (build-char-set (is:make-range (char->integer #\2)) c))
|
||||
(r3 (build-char-set (is:make-range (char->integer #\3)) c))
|
||||
(rc (build-concat r1 r2 c))
|
||||
(rc2 (build-concat r2 r1 c))
|
||||
(rr (build-repeat 0 +inf.0 rc c))
|
||||
(ro (build-or `(,rr ,rc ,rr) c))
|
||||
(ro2 (build-or `(,rc ,rr ,z) c))
|
||||
(ro3 (build-or `(,rr ,rc) c))
|
||||
(ro4 (build-or `(,(build-or `(,r1 ,r2) c)
|
||||
,(build-or `(,r2 ,r3) c)) c))
|
||||
(ra (build-and `(,rr ,rc ,rr) c))
|
||||
(ra2 (build-and `(,rc ,rr) c))
|
||||
(ra3 (build-and `(,rr ,rc) c))
|
||||
(ra4 (build-and `(,(build-and `(,r3 ,r2) c)
|
||||
,(build-and `(,r2 ,r1) c)) c))
|
||||
(rn (build-neg z c))
|
||||
(rn2 (build-neg r1 c)))
|
||||
|
||||
((isc (char-setR-chars r1)) (isc (is:make-range (char->integer #\1))))
|
||||
((isc (char-setR-chars r2)) (isc (is:make-range (char->integer #\2))))
|
||||
((isc (char-setR-chars r3)) (isc (is:make-range (char->integer #\3))))
|
||||
((build-char-set (is:make-range) c) z)
|
||||
((build-concat r1 e c) r1)
|
||||
((build-concat e r1 c) r1)
|
||||
((build-concat r1 z c) z)
|
||||
((build-concat z r1 c) z)
|
||||
((build-concat r1 r2 c) rc)
|
||||
((concatR-re1 rc) r1)
|
||||
((concatR-re2 rc) r2)
|
||||
((concatR-re1 rc2) r2)
|
||||
((concatR-re2 rc2) r1)
|
||||
(ro ro2)
|
||||
(ro ro3)
|
||||
(ro4 (build-or `(,r1 ,r2 ,r3) c))
|
||||
((orR-res ro) (list rc rr))
|
||||
((orR-res ro4) (list r1 r2 r3))
|
||||
((build-or null c) z)
|
||||
((build-or `(,r1 ,z) c) r1)
|
||||
((build-repeat 0 +inf.0 rc c) rr)
|
||||
((build-repeat 0 1 z c) e)
|
||||
((build-repeat 0 0 rc c) e)
|
||||
((build-repeat 0 +inf.0 z c) e)
|
||||
((build-repeat -1 +inf.0 z c) e)
|
||||
((build-repeat 0 +inf.0 (build-repeat 0 +inf.0 rc c) c)
|
||||
(build-repeat 0 +inf.0 rc c))
|
||||
((build-repeat 20 20 (build-repeat 0 +inf.0 rc c) c)
|
||||
(build-repeat 0 +inf.0 rc c))
|
||||
((build-repeat 20 20 (build-repeat 1 +inf.0 rc c) c)
|
||||
(build-repeat 20 +inf.0 rc c))
|
||||
((build-repeat 1 1 rc c) rc)
|
||||
((repeatR-re rr) rc)
|
||||
(ra ra2)
|
||||
(ra ra3)
|
||||
(ra4 (build-and `(,r1 ,r2 ,r3) c))
|
||||
((andR-res ra) (list rc rr))
|
||||
((andR-res ra4) (list r1 r2 r3))
|
||||
((build-and null c) (build-neg z c))
|
||||
((build-and `(,r1 ,z) c) z)
|
||||
((build-and `(,r1) c) r1)
|
||||
((build-neg r1 c) (build-neg r1 c))
|
||||
((build-neg (build-neg r1 c) c) r1)
|
||||
((negR-re (build-neg r2 c)) r2)
|
||||
((re-nullable? r1) #f)
|
||||
((re-nullable? rc) #f)
|
||||
((re-nullable? (build-concat rr rr c)) #t)
|
||||
((re-nullable? rr) #t)
|
||||
((re-nullable? (build-repeat 0 1 rc c)) #t)
|
||||
((re-nullable? (build-repeat 1 2 rc c)) #f)
|
||||
((re-nullable? (build-repeat 1 2 (build-or (list e r1) c) c)) #t)
|
||||
((re-nullable? ro) #t)
|
||||
((re-nullable? (build-or `(,r1 ,r2) c)) #f)
|
||||
((re-nullable? (build-and `(,r1 ,e) c)) #f)
|
||||
((re-nullable? (build-and `(,rr ,e) c)) #t)
|
||||
((re-nullable? (build-neg r1 c)) #t)
|
||||
((re-nullable? (build-neg rr c)) #f))
|
||||
|
||||
(test-block ((c (make-cache))
|
||||
(isc is:integer-set-contents)
|
||||
(r1 (->re #\1 c))
|
||||
(r2 (->re #\2 c))
|
||||
(r3-5 (->re '(char-range #\3 #\5) c))
|
||||
(r4 (build-or `(,r1 ,r2) c))
|
||||
(r5 (->re `(union ,r3-5 #\7) c))
|
||||
(r6 (->re #\6 c)))
|
||||
((flatten-res null orR? orR-res is:union c) null)
|
||||
((isc (char-setR-chars (car (flatten-res `(,r1) orR? orR-res is:union c))))
|
||||
(isc (is:make-range (char->integer #\1))))
|
||||
((isc (char-setR-chars (car (flatten-res `(,r4) orR? orR-res is:union c))))
|
||||
(isc (is:make-range (char->integer #\1) (char->integer #\2))))
|
||||
((isc (char-setR-chars (car (flatten-res `(,r6 ,r5 ,r4 ,r3-5 ,r2 ,r1)
|
||||
orR? orR-res is:union c))))
|
||||
(isc (is:make-range (char->integer #\1) (char->integer #\7))))
|
||||
((flatten-res `(,r1 ,r2) andR? andR-res (λ (x y)
|
||||
(let-values (((i _ __)
|
||||
(is:split x y)))
|
||||
i))
|
||||
c)
|
||||
(list z)))
|
||||
|
||||
;; ->re
|
||||
(test-block ((c (make-cache))
|
||||
(isc is:integer-set-contents)
|
||||
(r (->re #\a c))
|
||||
(rr (->re `(concatenation ,r ,r) c))
|
||||
(rrr (->re `(concatenation ,r ,rr) c))
|
||||
(rrr* (->re `(repetition 0 +inf.0 ,rrr) c)))
|
||||
((isc (char-setR-chars r)) (isc (is:make-range (char->integer #\a))))
|
||||
((->re "" c) e)
|
||||
((->re "asdf" c) (->re `(concatenation #\a #\s #\d #\f) c))
|
||||
((->re r c) r)
|
||||
((->re `(repetition 0 +inf.0 ,r) c) (build-repeat 0 +inf.0 r c))
|
||||
((->re `(repetition 1 +inf.0 ,r) c) (build-repeat 1 +inf.0 r c))
|
||||
((->re `(repetition 0 1 ,r) c) (build-repeat 0 1 r c))
|
||||
((->re `(repetition 0 1 ,rrr*) c) rrr*)
|
||||
((->re `(union (union (char-range #\a #\c)
|
||||
(char-complement (char-range #\000 #\110)
|
||||
(char-range #\112 ,(integer->char max-char-num))))
|
||||
(union (repetition 0 +inf.0 #\2))) c)
|
||||
(build-or (list (build-char-set (is:union (is:make-range 73)
|
||||
(is:make-range 97 99))
|
||||
c)
|
||||
(build-repeat 0 +inf.0 (build-char-set (is:make-range 50) c) c))
|
||||
c))
|
||||
((->re `(union ,rr ,rrr) c) (build-or (list rr rrr) c))
|
||||
((->re `(union ,r) c) r)
|
||||
((->re `(union) c) z)
|
||||
((->re `(intersection (intersection #\111
|
||||
(char-complement (char-range #\000 #\110)
|
||||
(char-range #\112 ,(integer->char max-char-num))))
|
||||
(intersection (repetition 0 +inf.0 #\2))) c)
|
||||
(build-and (list (build-char-set (is:make-range 73) c)
|
||||
(build-repeat 0 +inf.0 (build-char-set (is:make-range 50) c) c))
|
||||
c))
|
||||
((->re `(intersection (intersection #\000 (char-complement (char-range #\000 #\110)
|
||||
(char-range #\112 ,(integer->char max-char-num))))
|
||||
(intersection (repetition 0 +inf.0 #\2))) c)
|
||||
z)
|
||||
((->re `(intersection ,rr ,rrr) c) (build-and (list rr rrr) c))
|
||||
((->re `(intersection ,r) c) r)
|
||||
((->re `(intersection) c) (build-neg z c))
|
||||
((->re `(complement ,r) c) (build-neg r c))
|
||||
((->re `(concatenation) c) e)
|
||||
((->re `(concatenation ,rrr*) c) rrr*)
|
||||
(rr (build-concat r r c))
|
||||
((->re `(concatenation ,r ,rr ,rrr) c)
|
||||
(build-concat r (build-concat rr rrr c) c))
|
||||
((isc (char-setR-chars (->re `(char-range #\1 #\1) c))) (isc (is:make-range 49)))
|
||||
((isc (char-setR-chars (->re `(char-range #\1 #\9) c))) (isc (is:make-range 49 57)))
|
||||
((isc (char-setR-chars (->re `(char-range "1" "1") c))) (isc (is:make-range 49)))
|
||||
((isc (char-setR-chars (->re `(char-range "1" "9") c))) (isc (is:make-range 49 57)))
|
||||
((->re `(char-range "9" "1") c) z)
|
||||
((isc (char-setR-chars (->re `(char-complement) c)))
|
||||
(isc (char-setR-chars (->re `(char-range #\000 ,(integer->char max-char-num)) c))))
|
||||
((isc (char-setR-chars (->re `(char-complement #\001 (char-range #\002 ,(integer->char max-char-num))) c)))
|
||||
(isc (is:make-range 0)))
|
||||
)
|
||||
|
||||
|
||||
@ -0,0 +1,183 @@
|
||||
#lang racket/base
|
||||
(require "util.rkt" syntax/id-table racket/syntax)
|
||||
(provide parse)
|
||||
|
||||
(define (bad-args stx num)
|
||||
(raise-syntax-error #f (format "incorrect number of arguments (should have ~a)" num) stx))
|
||||
|
||||
;; char-range-arg: syntax-object syntax-object -> nat
|
||||
;; If c contains is a character or length 1 string, returns the integer
|
||||
;; for the character. Otherwise raises a syntax error.
|
||||
(define (char-range-arg stx containing-stx)
|
||||
(define c (syntax-e stx))
|
||||
(cond
|
||||
[(char? c) (char->integer c)]
|
||||
[(and (string? c) (= (string-length c) 1))
|
||||
(char->integer (string-ref c 0))]
|
||||
[else
|
||||
(raise-syntax-error
|
||||
#f
|
||||
"not a char or single-char string"
|
||||
containing-stx stx)]))
|
||||
|
||||
(module+ test
|
||||
(check-equal? (char-range-arg #'#\1 #'here) (char->integer #\1))
|
||||
(check-equal? (char-range-arg #'"1" #'here) (char->integer #\1)))
|
||||
|
||||
(define orig-insp (variable-reference->module-declaration-inspector
|
||||
(#%variable-reference)))
|
||||
(define (disarm stx)
|
||||
(syntax-disarm stx orig-insp))
|
||||
|
||||
;; parse : syntax-object (box (list-of syntax-object)) -> s-re (see re.rkt)
|
||||
;; checks for errors and generates the plain s-exp form for s
|
||||
;; Expands lex-abbrevs and applies lex-trans.
|
||||
(define (parse stx)
|
||||
(let loop ([stx stx]
|
||||
;; seen-lex-abbrevs: id-table
|
||||
[seen-lex-abbrevs (make-immutable-free-id-table)])
|
||||
(let ([recur (λ (s)
|
||||
(loop (syntax-rearm s stx)
|
||||
seen-lex-abbrevs))]
|
||||
[recur/abbrev (λ (s id)
|
||||
(loop (syntax-rearm s stx)
|
||||
(free-id-table-set seen-lex-abbrevs id id)))])
|
||||
(syntax-case (disarm stx) (repetition union intersection complement concatenation
|
||||
char-range char-complement)
|
||||
[_
|
||||
(identifier? stx)
|
||||
(let ([expansion (syntax-local-value/record stx (λ (v) #t))])
|
||||
(unless (lex-abbrev? expansion)
|
||||
(raise-syntax-error 'regular-expression
|
||||
"undefined abbreviation"
|
||||
stx))
|
||||
;; Check for cycles.
|
||||
(when (free-id-table-ref seen-lex-abbrevs stx (λ () #f))
|
||||
(raise-syntax-error 'regular-expression
|
||||
"illegal lex-abbrev cycle detected"
|
||||
stx
|
||||
#f
|
||||
(list (free-id-table-ref seen-lex-abbrevs stx))))
|
||||
(recur/abbrev ((lex-abbrev-get-abbrev expansion)) stx))]
|
||||
[_
|
||||
(or (char? (syntax-e stx)) (string? (syntax-e stx)))
|
||||
(syntax-e stx)]
|
||||
[(repetition ARG ...)
|
||||
(let ([arg-list (syntax->list #'(ARG ...))])
|
||||
(unless (= 3 (length arg-list))
|
||||
(bad-args stx 2))
|
||||
(define low (syntax-e (car arg-list)))
|
||||
(define high (syntax-e (cadr arg-list)))
|
||||
(define re (caddr arg-list))
|
||||
(unless (and (number? low) (exact? low) (integer? low) (>= low 0))
|
||||
(raise-syntax-error #f "not a non-negative exact integer" stx (car arg-list)))
|
||||
(unless (or (and (number? high) (exact? high) (integer? high) (>= high 0))
|
||||
(eqv? high +inf.0))
|
||||
(raise-syntax-error #f "not a non-negative exact integer or +inf.0" stx (cadr arg-list)))
|
||||
(unless (<= low high)
|
||||
(raise-syntax-error #f "the first argument is not less than or equal to the second argument" stx))
|
||||
`(repetition ,low ,high ,(recur re)))]
|
||||
[(union RE ...)
|
||||
`(union ,@(map recur (syntax->list #'(RE ...))))]
|
||||
[(intersection RE ...)
|
||||
`(intersection ,@(map recur (syntax->list #'(RE ...))))]
|
||||
[(complement RE ...)
|
||||
(let ([re-list (syntax->list #'(RE ...))])
|
||||
(unless (= 1 (length re-list))
|
||||
(bad-args stx 1))
|
||||
`(complement ,(recur (car re-list))))]
|
||||
[(concatenation RE ...)
|
||||
`(concatenation ,@(map recur (syntax->list #'(RE ...))))]
|
||||
[(char-range ARG ...)
|
||||
(let ((arg-list (syntax->list #'(ARG ...))))
|
||||
(unless (= 2 (length arg-list))
|
||||
(bad-args stx 2))
|
||||
(let ([i1 (char-range-arg (car arg-list) stx)]
|
||||
[i2 (char-range-arg (cadr arg-list) stx)])
|
||||
(if (<= i1 i2)
|
||||
`(char-range ,(integer->char i1) ,(integer->char i2))
|
||||
(raise-syntax-error #f "the first argument does not precede or equal second argument" stx))))]
|
||||
[(char-complement ARG ...)
|
||||
(let ([arg-list (syntax->list #'(ARG ...))])
|
||||
(unless (= 1 (length arg-list))
|
||||
(bad-args stx 1))
|
||||
(define parsed (recur (car arg-list)))
|
||||
(unless (char-set? parsed)
|
||||
(raise-syntax-error #f "not a character set" stx (car arg-list)))
|
||||
`(char-complement ,parsed))]
|
||||
((OP form ...)
|
||||
(identifier? #'OP)
|
||||
(let* ([expansion (syntax-local-value/record #'OP (λ (v) #t))])
|
||||
(cond
|
||||
[(lex-trans? expansion)
|
||||
(recur ((lex-trans-f expansion) (disarm stx)))]
|
||||
[expansion
|
||||
(raise-syntax-error 'regular-expression "not a lex-trans" stx)]
|
||||
[else
|
||||
(raise-syntax-error 'regular-expression "undefined operator" stx)])))
|
||||
[_ (raise-syntax-error 'regular-expression "not a char, string, identifier, or (op args ...)" stx)]))))
|
||||
|
||||
|
||||
|
||||
;; char-set? : s-re -> bool
|
||||
;; A char-set is an re that matches only strings of length 1.
|
||||
;; char-set? is conservative.
|
||||
(define (char-set? s-re)
|
||||
(cond
|
||||
[(char? s-re)]
|
||||
[(string? s-re) (= (string-length s-re) 1)]
|
||||
[(list? s-re) (case (car s-re)
|
||||
[(union intersection) (andmap char-set? (cdr s-re))]
|
||||
[(char-range char-complement) #t]
|
||||
[(repetition) (and (= 1 (cadr s-re) (caddr s-re)) (char-set? (cadddr s-re)))]
|
||||
[(concatenation) (and (= 2 (length s-re)) (char-set? (cadr s-re)))]
|
||||
(else #f))]
|
||||
[else #f]))
|
||||
|
||||
(module+ test
|
||||
(require rackunit)
|
||||
(check-equal? (char-set? #\a) #t)
|
||||
(check-equal? (char-set? "12") #f)
|
||||
(check-equal? (char-set? "1") #t)
|
||||
(check-equal? (char-set? '(repetition 1 2 #\1)) #f)
|
||||
(check-equal? (char-set? '(repetition 1 1 "12")) #f)
|
||||
(check-equal? (char-set? '(repetition 1 1 "1")) #t)
|
||||
(check-equal? (char-set? '(repetition 6 6 "1")) #f)
|
||||
(check-equal? (char-set? '(union "1" "2" "3")) #t)
|
||||
(check-equal? (char-set? '(union "1" "" "3")) #f)
|
||||
(check-equal? (char-set? '(intersection "1" "2" (union "3" "4"))) #t)
|
||||
(check-equal? (char-set? '(intersection "1" "")) #f)
|
||||
(check-equal? (char-set? '(complement "1")) #f)
|
||||
(check-equal? (char-set? '(concatenation "1" "2")) #f)
|
||||
(check-equal? (char-set? '(concatenation "" "2")) #f)
|
||||
(check-equal? (char-set? '(concatenation "1")) #t)
|
||||
(check-equal? (char-set? '(concatenation "12")) #f)
|
||||
(check-equal? (char-set? '(char-range #\1 #\2)) #t)
|
||||
(check-equal? (char-set? '(char-complement #\1)) #t))
|
||||
|
||||
;; yikes... these test cases all have the wrong arity, now.
|
||||
;; and by "now", I mean it's been broken since before we
|
||||
;; moved to git.
|
||||
(module+ test
|
||||
(check-equal? (parse #'#\a) #\a)
|
||||
(check-equal? (parse #'"1") "1")
|
||||
(check-equal? (parse #'(repetition 1 1 #\1))
|
||||
'(repetition 1 1 #\1))
|
||||
(check-equal? (parse #'(repetition 0 +inf.0 #\1)) '(repetition 0 +inf.0 #\1))
|
||||
(check-equal? (parse #'(union #\1 (union "2") (union)))
|
||||
'(union #\1 (union "2") (union)))
|
||||
(check-equal? (parse #'(intersection #\1 (intersection "2") (intersection)))
|
||||
'(intersection #\1 (intersection "2") (intersection)))
|
||||
(check-equal? (parse #'(complement (union #\1 #\2)))
|
||||
'(complement (union #\1 #\2)))
|
||||
(check-equal? (parse #'(concatenation "1" "2" (concatenation)))
|
||||
'(concatenation "1" "2" (concatenation)))
|
||||
(check-equal? (parse #'(char-range "1" #\1)) '(char-range #\1 #\1))
|
||||
(check-equal? (parse #'(char-range #\1 "1")) '(char-range #\1 #\1))
|
||||
(check-equal? (parse #'(char-range "1" "3")) '(char-range #\1 #\3))
|
||||
(check-equal? (parse #'(char-complement (union "1" "2")))
|
||||
'(char-complement (union "1" "2")))
|
||||
(check-equal? (parse #'(char-complement (repetition 1 1 "1")))
|
||||
'(char-complement (repetition 1 1 "1")))
|
||||
(check-exn #rx"not a character set"
|
||||
(λ () (parse #'(char-complement (repetition 6 6 "1"))))))
|
||||
@ -0,0 +1,7 @@
|
||||
#lang racket/base
|
||||
(provide make-terminals-def terminals-def-t terminals-def?
|
||||
make-e-terminals-def e-terminals-def-t e-terminals-def?)
|
||||
|
||||
;; The things needed at compile time to handle definition of tokens
|
||||
(define-struct terminals-def (t))
|
||||
(define-struct e-terminals-def (t))
|
||||
@ -0,0 +1,80 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base "token-syntax.rkt"))
|
||||
|
||||
;; Defining tokens
|
||||
|
||||
(provide define-tokens define-empty-tokens make-token token?
|
||||
(protect-out (rename-out [token-name real-token-name]))
|
||||
(protect-out (rename-out [token-value real-token-value]))
|
||||
(rename-out [token-name* token-name][token-value* token-value])
|
||||
(struct-out position)
|
||||
(struct-out position-token)
|
||||
(struct-out srcloc-token))
|
||||
|
||||
|
||||
;; A token is either
|
||||
;; - symbol
|
||||
;; - (make-token symbol any)
|
||||
(define-struct token (name value) #:inspector (make-inspector))
|
||||
|
||||
;; token-name*: token -> symbol
|
||||
(define (token-name* t)
|
||||
(cond
|
||||
[(symbol? t) t]
|
||||
[(token? t) (token-name t)]
|
||||
[else (raise-type-error 'token-name "symbol or struct:token" 0 t)]))
|
||||
|
||||
;; token-value*: token -> any
|
||||
(define (token-value* t)
|
||||
(cond
|
||||
[(symbol? t) #f]
|
||||
[(token? t) (token-value t)]
|
||||
[else (raise-type-error 'token-value "symbol or struct:token" 0 t)]))
|
||||
|
||||
(define-for-syntax (make-ctor-name n)
|
||||
(datum->syntax n
|
||||
(string->symbol (format "token-~a" (syntax-e n)))
|
||||
n
|
||||
n))
|
||||
|
||||
(define-for-syntax ((make-define-tokens empty?) stx)
|
||||
(syntax-case stx ()
|
||||
[(_ NAME (TOKEN ...))
|
||||
(andmap identifier? (syntax->list #'(TOKEN ...)))
|
||||
(with-syntax (((marked-token ...)
|
||||
(map values #;(make-syntax-introducer)
|
||||
(syntax->list #'(TOKEN ...)))))
|
||||
(quasisyntax/loc stx
|
||||
(begin
|
||||
(define-syntax NAME
|
||||
#,(if empty?
|
||||
#'(make-e-terminals-def (quote-syntax (marked-token ...)))
|
||||
#'(make-terminals-def (quote-syntax (marked-token ...)))))
|
||||
#,@(map
|
||||
(λ (n)
|
||||
(when (eq? (syntax-e n) 'error)
|
||||
(raise-syntax-error
|
||||
#f
|
||||
"Cannot define a token named error."
|
||||
stx))
|
||||
(if empty?
|
||||
#`(define (#,(make-ctor-name n))
|
||||
'#,n)
|
||||
#`(define (#,(make-ctor-name n) x)
|
||||
(make-token '#,n x))))
|
||||
(syntax->list #'(TOKEN ...)))
|
||||
#;(define marked-token #f) #;...)))]
|
||||
[(_ ...)
|
||||
(raise-syntax-error #f
|
||||
"must have the form (define-tokens name (identifier ...)) or (define-empty-tokens name (identifier ...))"
|
||||
stx)]))
|
||||
|
||||
(define-syntax define-tokens (make-define-tokens #f))
|
||||
(define-syntax define-empty-tokens (make-define-tokens #t))
|
||||
|
||||
(define-struct position (offset line col) #:inspector #f)
|
||||
(define-struct position-token (token start-pos end-pos) #:inspector #f)
|
||||
|
||||
(define-struct srcloc-token (token srcloc) #:inspector #f)
|
||||
|
||||
|
||||
@ -0,0 +1,65 @@
|
||||
#lang racket/base
|
||||
(require racket/promise "util.rkt")
|
||||
|
||||
(provide (all-defined-out))
|
||||
|
||||
;; mapped-chars : (listof (list nat nat bool))
|
||||
(define mapped-chars (make-known-char-range-list))
|
||||
|
||||
;; get-chars-for-x : (nat -> bool) (listof (list nat nat bool)) -> (listof (cons nat nat))
|
||||
(define (get-chars-for char-x? mapped-chars)
|
||||
(cond
|
||||
[(null? mapped-chars) null]
|
||||
[else
|
||||
(define range (car mapped-chars))
|
||||
(define low (car range))
|
||||
(define high (cadr range))
|
||||
(define x (char-x? low))
|
||||
(cond
|
||||
[(caddr range)
|
||||
(if x
|
||||
(cons (cons low high) (get-chars-for char-x? (cdr mapped-chars)))
|
||||
(get-chars-for char-x? (cdr mapped-chars)))]
|
||||
[else
|
||||
(let loop ([range-start low]
|
||||
[i (car range)]
|
||||
[parity x])
|
||||
(cond
|
||||
[(> i high)
|
||||
(if parity
|
||||
(cons (cons range-start high) (get-chars-for char-x? (cdr mapped-chars)))
|
||||
(get-chars-for char-x? (cdr mapped-chars)))]
|
||||
[(eq? parity (char-x? i))
|
||||
(loop range-start (add1 i) parity)]
|
||||
[parity (cons (cons range-start (sub1 i)) (loop i (add1 i) #f))]
|
||||
[else (loop i (add1 i) #t)]))])]))
|
||||
|
||||
(define (compute-ranges x?)
|
||||
(delay (get-chars-for (λ (x) (x? (integer->char x))) mapped-chars)))
|
||||
|
||||
(define alphabetic-ranges (compute-ranges char-alphabetic?)) ;; 325
|
||||
(define lower-case-ranges (compute-ranges char-lower-case?)) ;; 405
|
||||
(define upper-case-ranges (compute-ranges char-upper-case?)) ;; 380
|
||||
(define title-case-ranges (compute-ranges char-title-case?)) ;; 10
|
||||
(define numeric-ranges (compute-ranges char-numeric?)) ;; 47
|
||||
(define symbolic-ranges (compute-ranges char-symbolic?)) ;; 153
|
||||
(define punctuation-ranges (compute-ranges char-punctuation?)) ;; 86
|
||||
(define graphic-ranges (compute-ranges char-graphic?)) ;; 401
|
||||
(define whitespace-ranges (compute-ranges char-whitespace?)) ;; 10
|
||||
(define blank-ranges (compute-ranges char-blank?)) ;; 9
|
||||
#;(define hexadecimal-ranges (compute-ranges char-hexadecimal?))
|
||||
(define iso-control-ranges (compute-ranges char-iso-control?)) ;; 2
|
||||
|
||||
|
||||
|
||||
(module+ test
|
||||
(require rackunit)
|
||||
(check-equal? (get-chars-for odd? '()) '())
|
||||
(check-equal? (get-chars-for odd? '((1 4 #f) (8 13 #f)))
|
||||
'((1 . 1) (3 . 3) (9 . 9) (11 . 11) (13 . 13)))
|
||||
(check-equal? (get-chars-for (λ (x)
|
||||
(odd? (quotient x 10)))
|
||||
'((1 5 #t) (17 19 #t) (21 51 #f)))
|
||||
'((17 . 19) (30 . 39) (50 . 51))))
|
||||
|
||||
|
||||
@ -0,0 +1,127 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base))
|
||||
|
||||
(provide (all-defined-out))
|
||||
|
||||
(define max-char-num #x10FFFF)
|
||||
|
||||
(define-struct lex-abbrev (get-abbrev))
|
||||
(define-struct lex-trans (f))
|
||||
|
||||
(module+ test
|
||||
(require rackunit))
|
||||
|
||||
(define-syntax (test-block stx)
|
||||
(syntax-case stx ()
|
||||
[(_ defs (code right-ans) ...)
|
||||
#'(module+ test
|
||||
(require rackunit)
|
||||
(let* defs
|
||||
(let ([real-ans code])
|
||||
(check-equal? real-ans right-ans)) ...))]))
|
||||
|
||||
#;(define-syntax test-block
|
||||
(syntax-rules ()
|
||||
((_ x ...) (void))))
|
||||
|
||||
|
||||
;; A cache is (X ( -> Y) -> Y)
|
||||
;; make-cache : -> cache
|
||||
;; table map Xs to Ys. If key is mapped, its value is returned.
|
||||
;; Otherwise, build is invoked and its result is placed in the table and
|
||||
;; returned.
|
||||
;; Xs are compared with equal?
|
||||
(define (make-cache)
|
||||
(let ([table (make-hash)])
|
||||
(λ (key build)
|
||||
(hash-ref table key (λ ()
|
||||
(let ([new (build)])
|
||||
(hash-set! table key new)
|
||||
new))))))
|
||||
|
||||
(module+ test
|
||||
(define cache (make-cache))
|
||||
(check-equal? (cache '(s 1 2) (λ () 9)) 9)
|
||||
(check-equal? (cache '(s 2 1) (λ () 8)) 8)
|
||||
(check-equal? (cache '(s 1 2) (λ () 1)) 9)
|
||||
(check-equal? (cache (cons 's (cons 0 (cons +inf.0 10)))
|
||||
(λ () 22)) 22)
|
||||
(check-equal? (cache (cons 's (cons 0 (cons +inf.0 10)))
|
||||
(λ () 1)) 22))
|
||||
|
||||
|
||||
|
||||
;; make-counter : -> -> nat
|
||||
;; makes a function that returns a higher number by 1, each time
|
||||
;; it is called.
|
||||
(define (make-counter)
|
||||
(let ([counter 0])
|
||||
(λ ()
|
||||
(begin0
|
||||
counter
|
||||
(set! counter (add1 counter))))))
|
||||
|
||||
(module+ test
|
||||
(define c (make-counter))
|
||||
(define d (make-counter))
|
||||
(check-equal? (c) 0)
|
||||
(check-equal? (d) 0)
|
||||
(check-equal? (c) 1)
|
||||
(check-equal? (d) 1)
|
||||
(check-equal? (c) 2))
|
||||
|
||||
|
||||
;; remove-dups : (list-of X) (X -> number) -> (list-of X)
|
||||
;; removes the entries from l that have the same index as a
|
||||
;; previous entry. l must be grouped by indexes.
|
||||
(define (remove-dups l index acc)
|
||||
(cond
|
||||
[(null? l) (reverse acc)]
|
||||
[(null? acc) (remove-dups (cdr l) index (cons (car l) acc))]
|
||||
[(= (index (car acc)) (index (car l)))
|
||||
(remove-dups (cdr l) index acc)]
|
||||
[else
|
||||
(remove-dups (cdr l) index (cons (car l) acc))]))
|
||||
|
||||
|
||||
(module+ test
|
||||
(check-equal? (remove-dups '((1 2) (2 2) (1 3) (1 4)
|
||||
(100 4) (0 5)) cadr null)
|
||||
'((1 2) (1 3) (1 4) (0 5)))
|
||||
(check-equal? (remove-dups null error null) null))
|
||||
|
||||
;; do-simple-equiv : (list-of X) (X -> nat) -> (list-of X)
|
||||
;; Sorts l according to index and removes the entries with duplicate
|
||||
;; indexes.
|
||||
(define (do-simple-equiv l index)
|
||||
(define ordered (sort l (λ (a b) (< (index a) (index b)))))
|
||||
(remove-dups ordered index null))
|
||||
|
||||
(module+ test
|
||||
(check-equal? (do-simple-equiv '((2 2) (1 4) (1 2)
|
||||
(100 4) (1 3) (0 5))
|
||||
cadr)
|
||||
'((2 2) (1 3) (1 4) (0 5)))
|
||||
(check-equal? (do-simple-equiv null error) null))
|
||||
|
||||
;; replace : (list-of X) (X -> bool) (X -> (list-of X)) (list-of X) ->
|
||||
;; (list-of X)
|
||||
;; If (pred? r) for some r in l, splice (get r) in place of r in the resulting
|
||||
;; list.
|
||||
(define (replace l pred? get acc)
|
||||
(cond
|
||||
[(null? l) acc]
|
||||
[(pred? (car l)) (replace (cdr l) pred? get (append (get (car l)) acc))]
|
||||
[else (replace (cdr l) pred? get (cons (car l) acc))]))
|
||||
|
||||
|
||||
(module+ test
|
||||
(check-equal? (replace null void (λ () (list 1)) null) null)
|
||||
(check-equal? (replace '(1 2 3 4 3 5)
|
||||
(λ (x) (= x 3))
|
||||
(λ (x) (list 1 2 3))
|
||||
null)
|
||||
'(5 1 2 3 4 1 2 3 2 1)))
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,250 @@
|
||||
#lang racket/base
|
||||
;; Constructs to create and access grammars, the internal
|
||||
;; representation of the input to the parser generator.
|
||||
|
||||
(require racket/class
|
||||
(except-in racket/list remove-duplicates)
|
||||
"yacc-helper.rkt"
|
||||
racket/contract)
|
||||
|
||||
;; Each production has a unique index 0 <= index <= number of productions
|
||||
(define-struct prod (lhs rhs index prec action) #:inspector (make-inspector) #:mutable)
|
||||
|
||||
;; The dot-pos field is the index of the element in the rhs
|
||||
;; of prod that the dot immediately precedes.
|
||||
;; Thus 0 <= dot-pos <= (vector-length rhs).
|
||||
(define-struct item (prod dot-pos) #:inspector (make-inspector))
|
||||
|
||||
;; gram-sym = (union term? non-term?)
|
||||
;; Each term has a unique index 0 <= index < number of terms
|
||||
;; Each non-term has a unique index 0 <= index < number of non-terms
|
||||
(define-struct term (sym index prec) #:inspector (make-inspector) #:mutable)
|
||||
(define-struct non-term (sym index) #:inspector (make-inspector) #:mutable)
|
||||
|
||||
;; a precedence declaration.
|
||||
(define-struct prec (num assoc) #:inspector (make-inspector))
|
||||
|
||||
(provide/contract
|
||||
[make-item (prod? (or/c #f natural-number/c) . -> . item?)]
|
||||
[make-term (symbol? (or/c #f natural-number/c) (or/c prec? #f) . -> . term?)]
|
||||
[make-non-term (symbol? (or/c #f natural-number/c) . -> . non-term?)]
|
||||
[make-prec (natural-number/c (or/c 'left 'right 'nonassoc) . -> . prec?)]
|
||||
[make-prod (non-term? (vectorof (or/c non-term? term?))
|
||||
(or/c #f natural-number/c) (or/c #f prec?) syntax? . -> . prod?)])
|
||||
|
||||
(provide
|
||||
;; Things that work on items
|
||||
start-item? item-prod item->string
|
||||
sym-at-dot move-dot-right item<? item-dot-pos
|
||||
|
||||
;; Things that operate on grammar symbols
|
||||
gram-sym-symbol gram-sym-index term-prec gram-sym->string
|
||||
non-term? term? non-term<? term<?
|
||||
term-list->bit-vector term-index non-term-index
|
||||
|
||||
;; Things that work on precs
|
||||
prec-num prec-assoc
|
||||
|
||||
grammar%
|
||||
|
||||
;; Things that work on productions
|
||||
prod-index prod-prec prod-rhs prod-lhs prod-action)
|
||||
|
||||
|
||||
;;---------------------- LR items --------------------------
|
||||
|
||||
;; item<?: LR-item * LR-item -> bool
|
||||
;; Lexicographic comparison on two items.
|
||||
(define (item<? i1 i2)
|
||||
(define p1 (prod-index (item-prod i1)))
|
||||
(define p2 (prod-index (item-prod i2)))
|
||||
(or (< p1 p2)
|
||||
(and (= p1 p2)
|
||||
(< (item-dot-pos i1) (item-dot-pos i2)))))
|
||||
|
||||
;; start-item?: LR-item -> bool
|
||||
;; The start production always has index 0
|
||||
(define (start-item? i)
|
||||
(zero? (non-term-index (prod-lhs (item-prod i)))))
|
||||
|
||||
|
||||
;; move-dot-right: LR-item -> LR-item | #f
|
||||
;; moves the dot to the right in the item, unless it is at its
|
||||
;; rightmost, then it returns false
|
||||
(define (move-dot-right i)
|
||||
(cond
|
||||
[(= (item-dot-pos i) (vector-length (prod-rhs (item-prod i)))) #f]
|
||||
[else (make-item (item-prod i)
|
||||
(add1 (item-dot-pos i)))]))
|
||||
|
||||
;; sym-at-dot: LR-item -> gram-sym | #f
|
||||
;; returns the symbol after the dot in the item or #f if there is none
|
||||
(define (sym-at-dot i)
|
||||
(define dp (item-dot-pos i))
|
||||
(define rhs (prod-rhs (item-prod i)))
|
||||
(cond
|
||||
[(= dp (vector-length rhs)) #f]
|
||||
[else (vector-ref rhs dp)]))
|
||||
|
||||
|
||||
;; print-item: LR-item ->
|
||||
(define (item->string it)
|
||||
(define print-sym (λ (i)
|
||||
(let ((gs (vector-ref (prod-rhs (item-prod it)) i)))
|
||||
(cond
|
||||
((term? gs) (format "~a " (term-sym gs)))
|
||||
(else (format "~a " (non-term-sym gs)))))))
|
||||
(string-append
|
||||
(format "~a -> " (non-term-sym (prod-lhs (item-prod it))))
|
||||
(let loop ((i 0))
|
||||
(cond
|
||||
[(= i (vector-length (prod-rhs (item-prod it))))
|
||||
(if (= i (item-dot-pos it))
|
||||
". "
|
||||
"")]
|
||||
[(= i (item-dot-pos it))
|
||||
(string-append ". " (print-sym i) (loop (add1 i)))]
|
||||
[else (string-append (print-sym i) (loop (add1 i)))]))))
|
||||
|
||||
;; --------------------- Grammar Symbols --------------------------
|
||||
|
||||
(define (non-term<? nt1 nt2)
|
||||
(< (non-term-index nt1) (non-term-index nt2)))
|
||||
|
||||
(define (term<? nt1 nt2)
|
||||
(< (term-index nt1) (term-index nt2)))
|
||||
|
||||
(define (gram-sym-index gs)
|
||||
(if (term? gs)
|
||||
(term-index gs)
|
||||
(non-term-index gs)))
|
||||
|
||||
(define (gram-sym-symbol gs)
|
||||
(if (term? gs)
|
||||
(term-sym gs)
|
||||
(non-term-sym gs)))
|
||||
|
||||
(define (gram-sym->string gs)
|
||||
(symbol->string (gram-sym-symbol gs)))
|
||||
|
||||
;; term-list->bit-vector: term list -> int
|
||||
;; Creates a number where the nth bit is 1 if the term with index n is in
|
||||
;; the list, and whose nth bit is 0 otherwise
|
||||
(define (term-list->bit-vector terms)
|
||||
(if (null? terms)
|
||||
0
|
||||
(bitwise-ior (arithmetic-shift 1 (term-index (car terms)))
|
||||
(term-list->bit-vector (cdr terms)))))
|
||||
|
||||
|
||||
;; ------------------------- Grammar ------------------------------
|
||||
|
||||
(define grammar%
|
||||
(class object%
|
||||
(super-instantiate ())
|
||||
;; prods: production list list
|
||||
;; where there is one production list per non-term
|
||||
(init prods)
|
||||
;; init-prods: production list
|
||||
;; The productions parsing can start from
|
||||
;; nullable-non-terms is indexed by the non-term-index and is true iff non-term is nullable
|
||||
(init-field init-prods terms non-terms end-terms)
|
||||
|
||||
;; list of all productions
|
||||
(define all-prods (apply append prods))
|
||||
(define num-prods (length all-prods))
|
||||
(define num-terms (length terms))
|
||||
(define num-non-terms (length non-terms))
|
||||
|
||||
(for ([(nt count) (in-indexed non-terms)])
|
||||
(set-non-term-index! nt count))
|
||||
|
||||
(for ([(t count) (in-indexed terms)])
|
||||
(set-term-index! t count))
|
||||
|
||||
(for ([(prod count) (in-indexed all-prods)])
|
||||
(set-prod-index! prod count))
|
||||
|
||||
;; indexed by the index of the non-term - contains the list of productions for that non-term
|
||||
(define nt->prods
|
||||
(let ((v (make-vector (length prods) #f)))
|
||||
(for ([prods (in-list prods)])
|
||||
(vector-set! v (non-term-index (prod-lhs (car prods))) prods))
|
||||
v))
|
||||
|
||||
(define nullable-non-terms
|
||||
(nullable all-prods num-non-terms))
|
||||
|
||||
(define/public (get-num-terms) num-terms)
|
||||
(define/public (get-num-non-terms) num-non-terms)
|
||||
|
||||
(define/public (get-prods-for-non-term nt)
|
||||
(vector-ref nt->prods (non-term-index nt)))
|
||||
(define/public (get-prods) all-prods)
|
||||
(define/public (get-init-prods) init-prods)
|
||||
|
||||
(define/public (get-terms) terms)
|
||||
(define/public (get-non-terms) non-terms)
|
||||
|
||||
(define/public (get-num-prods) num-prods)
|
||||
(define/public (get-end-terms) end-terms)
|
||||
|
||||
(define/public (nullable-non-term? nt)
|
||||
(vector-ref nullable-non-terms (non-term-index nt)))
|
||||
|
||||
(define/public (nullable-after-dot? item)
|
||||
(define rhs (prod-rhs (item-prod item)))
|
||||
(define prod-length (vector-length rhs))
|
||||
(let loop ((i (item-dot-pos item)))
|
||||
(cond
|
||||
[(< i prod-length)
|
||||
(and (non-term? (vector-ref rhs i))
|
||||
(nullable-non-term? (vector-ref rhs i))
|
||||
(loop (add1 i)))]
|
||||
[(= i prod-length)])))
|
||||
|
||||
(define/public (nullable-non-term-thunk)
|
||||
(λ (nt) (nullable-non-term? nt)))
|
||||
(define/public (nullable-after-dot?-thunk)
|
||||
(λ (item) (nullable-after-dot? item)))))
|
||||
|
||||
|
||||
;; nullable: production list * int -> non-term set
|
||||
;; determines which non-terminals can derive epsilon
|
||||
(define (nullable prods num-nts)
|
||||
(define nullable (make-vector num-nts #f))
|
||||
(define added #f)
|
||||
|
||||
;; possible-nullable: producion list -> production list
|
||||
;; Removes all productions that have a terminal
|
||||
(define (possible-nullable prods)
|
||||
(for/list ([prod (in-list prods)]
|
||||
#:when (vector-andmap non-term? (prod-rhs prod)))
|
||||
prod))
|
||||
|
||||
;; set-nullables: production list -> production list
|
||||
;; makes one pass through the productions, adding the ones
|
||||
;; known to be nullable now to nullable and returning a list
|
||||
;; of productions that we don't know about yet.
|
||||
(define (set-nullables prods)
|
||||
(cond
|
||||
[(null? prods) null]
|
||||
[(vector-ref nullable (gram-sym-index (prod-lhs (car prods))))
|
||||
(set-nullables (cdr prods))]
|
||||
[(vector-andmap (λ (nt) (vector-ref nullable (gram-sym-index nt))) (prod-rhs (car prods)))
|
||||
(vector-set! nullable (gram-sym-index (prod-lhs (car prods))) #t)
|
||||
(set! added #t)
|
||||
(set-nullables (cdr prods))]
|
||||
[else (cons (car prods) (set-nullables (cdr prods)))]))
|
||||
(let loop ((P (possible-nullable prods)))
|
||||
(cond
|
||||
[(null? P) nullable]
|
||||
[else
|
||||
(set! added #f)
|
||||
(define new-P (set-nullables P))
|
||||
(if added
|
||||
(loop new-P)
|
||||
nullable)])))
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,53 @@
|
||||
#lang racket/base
|
||||
(provide digraph)
|
||||
|
||||
(define (zero-thunk) 0)
|
||||
|
||||
;; digraph:
|
||||
;; ('a list) * ('a -> 'a list) * ('a -> 'b) * ('b * 'b -> 'b) * (-> 'b)
|
||||
;; -> ('a -> 'b)
|
||||
;; DeRemer and Pennello 1982
|
||||
;; Computes (f x) = (f- x) union Union{(f y) | y in (edges x)}
|
||||
;; We use a hash-table to represent the result function 'a -> 'b set, so
|
||||
;; the values of type 'a must be comparable with eq?.
|
||||
|
||||
(define (digraph nodes edges f- union fail)
|
||||
(define results (make-hasheq))
|
||||
(define (f x) (hash-ref results x fail))
|
||||
;; Maps elements of 'a to integers.
|
||||
(define N (make-hasheq))
|
||||
(define (get-N x) (hash-ref N x zero-thunk))
|
||||
(define (set-N x d) (hash-set! N x d))
|
||||
(define stack null)
|
||||
(define (push x) (set! stack (cons x stack)))
|
||||
(define (pop) (begin0
|
||||
(car stack)
|
||||
(set! stack (cdr stack))))
|
||||
(define (depth) (length stack))
|
||||
|
||||
;; traverse: 'a ->
|
||||
(define (traverse x)
|
||||
(push x)
|
||||
(define d (depth))
|
||||
(set-N x d)
|
||||
(hash-set! results x (f- x))
|
||||
(for-each (λ (y)
|
||||
(when (= 0 (get-N y))
|
||||
(traverse y))
|
||||
(hash-set! results
|
||||
x
|
||||
(union (f x) (f y)))
|
||||
(set-N x (min (get-N x) (get-N y))))
|
||||
(edges x))
|
||||
(when (= d (get-N x))
|
||||
(let loop ([p (pop)])
|
||||
(set-N p +inf.0)
|
||||
(hash-set! results p (f x))
|
||||
(when (not (eq? x p))
|
||||
(loop (pop))))))
|
||||
;; Will map elements of 'a to 'b sets
|
||||
(for ([x (in-list nodes)]
|
||||
#:when (zero? (get-N x)))
|
||||
(traverse x))
|
||||
f)
|
||||
|
||||
@ -0,0 +1,297 @@
|
||||
#lang racket/base
|
||||
(require "yacc-helper.rkt"
|
||||
"../private-lex/token-syntax.rkt"
|
||||
"grammar.rkt"
|
||||
racket/class
|
||||
racket/contract
|
||||
(for-template racket/base))
|
||||
|
||||
;; routines for parsing the input to the parser generator and producing a
|
||||
;; grammar (See grammar.rkt)
|
||||
|
||||
(define (is-a-grammar%? x) (is-a? x grammar%))
|
||||
(provide/contract
|
||||
[parse-input ((listof identifier?) (listof identifier?) (listof identifier?)
|
||||
(or/c #f syntax?) syntax? any/c . -> . is-a-grammar%?)]
|
||||
[get-term-list ((listof identifier?) . -> . (listof identifier?))])
|
||||
|
||||
(define stx-for-original-property (read-syntax #f (open-input-string "original")))
|
||||
|
||||
;; get-args: ??? -> (values (listof syntax) (or/c #f (cons integer? stx)))
|
||||
(define (get-args i rhs src-pos term-defs)
|
||||
(define empty-table (make-hasheq))
|
||||
(define biggest-pos #f)
|
||||
(hash-set! empty-table 'error #t)
|
||||
(for* ([td (in-list term-defs)]
|
||||
[v (in-value (syntax-local-value td))]
|
||||
#:when (e-terminals-def? v)
|
||||
[s (in-list (syntax->list (e-terminals-def-t v)))])
|
||||
(hash-set! empty-table (syntax->datum s) #t))
|
||||
(define args
|
||||
(let get-args ([i i][rhs rhs])
|
||||
(cond
|
||||
[(null? rhs) null]
|
||||
[else
|
||||
(define b (car rhs))
|
||||
(define name (if (hash-ref empty-table (syntax->datum (car rhs)) #f)
|
||||
(gensym)
|
||||
(string->symbol (format "$~a" i))))
|
||||
(cond
|
||||
[src-pos
|
||||
(define start-pos-id
|
||||
(datum->syntax b (string->symbol (format "$~a-start-pos" i)) b stx-for-original-property))
|
||||
(define end-pos-id
|
||||
(datum->syntax b (string->symbol (format "$~a-end-pos" i)) b stx-for-original-property))
|
||||
(set! biggest-pos (cons start-pos-id end-pos-id))
|
||||
(list* (datum->syntax b name b stx-for-original-property)
|
||||
start-pos-id
|
||||
end-pos-id
|
||||
(get-args (add1 i) (cdr rhs)))]
|
||||
[else
|
||||
(list* (datum->syntax b name b stx-for-original-property)
|
||||
(get-args (add1 i) (cdr rhs)))])])))
|
||||
(values args biggest-pos))
|
||||
|
||||
;; Given the list of terminal symbols and the precedence/associativity definitions,
|
||||
;; builds terminal structures (See grammar.rkt)
|
||||
;; build-terms: symbol list * symbol list list -> term list
|
||||
(define (build-terms term-list precs)
|
||||
(define counter 0)
|
||||
;;(term-list (cons (gensym) term-list))
|
||||
;; Will map a terminal symbol to its precedence/associativity
|
||||
(define prec-table (make-hasheq))
|
||||
|
||||
;; Fill the prec table
|
||||
(for ([p-decl (in-list precs)])
|
||||
(define assoc (car p-decl))
|
||||
(for ([term-sym (in-list (cdr p-decl))])
|
||||
(hash-set! prec-table term-sym (make-prec counter assoc)))
|
||||
(set! counter (add1 counter)))
|
||||
|
||||
;; Build the terminal structures
|
||||
(for/list ([term-sym (in-list term-list)])
|
||||
(make-term term-sym
|
||||
#f
|
||||
(hash-ref prec-table term-sym (λ () #f)))))
|
||||
|
||||
;; Retrieves the terminal symbols from a terminals-def (See terminal-syntax.rkt)
|
||||
;; get-terms-from-def: identifier? -> (listof identifier?)
|
||||
(define (get-terms-from-def term-syn)
|
||||
(define t (syntax-local-value term-syn #f))
|
||||
(cond
|
||||
[(terminals-def? t) (syntax->list (terminals-def-t t))]
|
||||
[(e-terminals-def? t) (syntax->list (e-terminals-def-t t))]
|
||||
[else
|
||||
(raise-syntax-error
|
||||
'parser-tokens
|
||||
"undefined token group"
|
||||
term-syn)]))
|
||||
|
||||
(define (get-term-list term-group-names)
|
||||
(remove-duplicates
|
||||
(cons (datum->syntax #f 'error)
|
||||
(apply append (map get-terms-from-def term-group-names)))))
|
||||
|
||||
(define (parse-input term-defs start ends prec-decls prods src-pos)
|
||||
(define start-syms (map syntax-e start))
|
||||
(define list-of-terms (map syntax-e (get-term-list term-defs)))
|
||||
(define end-terms
|
||||
(for/list ([end (in-list ends)])
|
||||
(unless (memq (syntax-e end) list-of-terms)
|
||||
(raise-syntax-error
|
||||
'parser-end-tokens
|
||||
(format "End token ~a not defined as a token"
|
||||
(syntax-e end))
|
||||
end))
|
||||
(syntax-e end)))
|
||||
;; Get the list of terminals out of input-terms
|
||||
(define list-of-non-terms
|
||||
(syntax-case prods ()
|
||||
[((NON-TERM PRODUCTION ...) ...)
|
||||
(begin
|
||||
(for ([nts (in-list (syntax->list #'(NON-TERM ...)))]
|
||||
#:when (memq (syntax->datum nts) list-of-terms))
|
||||
(raise-syntax-error
|
||||
'parser-non-terminals
|
||||
(format "~a used as both token and non-terminal" (syntax->datum nts))
|
||||
nts))
|
||||
(let ([dup (duplicate-list? (syntax->datum #'(NON-TERM ...)))])
|
||||
(when dup
|
||||
(raise-syntax-error
|
||||
'parser-non-terminals
|
||||
(format "non-terminal ~a defined multiple times" dup)
|
||||
prods)))
|
||||
(syntax->datum #'(NON-TERM ...)))]
|
||||
[_ (raise-syntax-error
|
||||
'parser-grammar
|
||||
"Grammar must be of the form (grammar (non-terminal productions ...) ...)"
|
||||
prods)]))
|
||||
;; Check the precedence declarations for errors and turn them into data
|
||||
(define precs
|
||||
(syntax-case prec-decls ()
|
||||
[((TYPE TERM ...) ...)
|
||||
(let ([p-terms (syntax->datum #'(TERM ... ...))])
|
||||
(cond
|
||||
[(duplicate-list? p-terms) =>
|
||||
(λ (d)
|
||||
(raise-syntax-error
|
||||
'parser-precedences
|
||||
(format "duplicate precedence declaration for token ~a" d)
|
||||
prec-decls))]
|
||||
[else (for ([t (in-list (syntax->list #'(TERM ... ...)))]
|
||||
#:when (not (memq (syntax->datum t) list-of-terms)))
|
||||
(raise-syntax-error
|
||||
'parser-precedences
|
||||
(format "Precedence declared for non-token ~a" (syntax->datum t))
|
||||
t))
|
||||
(for ([type (in-list (syntax->list #'(TYPE ...)))]
|
||||
#:unless (memq (syntax->datum type) `(left right nonassoc)))
|
||||
(raise-syntax-error
|
||||
'parser-precedences
|
||||
"Associativity must be left, right or nonassoc"
|
||||
type))
|
||||
(syntax->datum prec-decls)]))]
|
||||
[#f null]
|
||||
[_ (raise-syntax-error
|
||||
'parser-precedences
|
||||
"Precedence declaration must be of the form (precs (assoc term ...) ...) where assoc is left, right or nonassoc"
|
||||
prec-decls)]))
|
||||
|
||||
(define terms (build-terms list-of-terms precs))
|
||||
(define non-terms (map (λ (non-term) (make-non-term non-term #f))
|
||||
list-of-non-terms))
|
||||
(define term-table (make-hasheq))
|
||||
(define non-term-table (make-hasheq))
|
||||
|
||||
(for ([t (in-list terms)])
|
||||
(hash-set! term-table (gram-sym-symbol t) t))
|
||||
|
||||
(for ([nt (in-list non-terms)])
|
||||
(hash-set! non-term-table (gram-sym-symbol nt) nt))
|
||||
|
||||
;; parse-prod: syntax-object -> gram-sym vector
|
||||
(define (parse-prod prod-so)
|
||||
(syntax-case prod-so ()
|
||||
[(PROD-RHS-SYM ...)
|
||||
(andmap identifier? (syntax->list prod-so))
|
||||
(begin
|
||||
(for ([t (in-list (syntax->list prod-so))]
|
||||
#:when (memq (syntax->datum t) end-terms))
|
||||
(raise-syntax-error
|
||||
'parser-production-rhs
|
||||
(format "~a is an end token and cannot be used in a production" (syntax->datum t))
|
||||
t))
|
||||
(for/vector ([s (in-list (syntax->list prod-so))])
|
||||
(cond
|
||||
[(hash-ref term-table (syntax->datum s) #f)]
|
||||
[(hash-ref non-term-table (syntax->datum s) #f)]
|
||||
[else (raise-syntax-error
|
||||
'parser-production-rhs
|
||||
(format "~a is not declared as a terminal or non-terminal" (syntax->datum s))
|
||||
s)])))]
|
||||
[_ (raise-syntax-error
|
||||
'parser-production-rhs
|
||||
"production right-hand-side must have form (symbol ...)"
|
||||
prod-so)]))
|
||||
|
||||
;; parse-action: syntax-object * syntax-object -> syntax-object
|
||||
(define (parse-action rhs act-in)
|
||||
(define-values (args biggest) (get-args 1 (syntax->list rhs) src-pos term-defs))
|
||||
(define act
|
||||
(if biggest
|
||||
(with-syntax ([(CAR-BIGGEST . CDR-BIGGEST) biggest]
|
||||
[$N-START-POS (datum->syntax (car biggest) '$n-start-pos)]
|
||||
[$N-END-POS (datum->syntax (cdr biggest) '$n-end-pos)]
|
||||
[ACT-IN act-in])
|
||||
#'(let ([$N-START-POS CAR-BIGGEST]
|
||||
[$N-END-POS CDR-BIGGEST])
|
||||
ACT-IN))
|
||||
act-in))
|
||||
(with-syntax ([ARGS args][ACT act])
|
||||
(syntax/loc #'ACT (λ ARGS ACT))))
|
||||
|
||||
;; parse-prod+action: non-term * syntax-object -> production
|
||||
(define (parse-prod+action nt prod-so)
|
||||
(syntax-case prod-so ()
|
||||
[(PROD-RHS ACTION)
|
||||
(let ([p (parse-prod #'PROD-RHS)])
|
||||
(make-prod
|
||||
nt
|
||||
p
|
||||
#f
|
||||
(let loop ([i (sub1 (vector-length p))])
|
||||
(if (>= i 0)
|
||||
(let ([gs (vector-ref p i)])
|
||||
(if (term? gs)
|
||||
(term-prec gs)
|
||||
(loop (sub1 i))))
|
||||
#f))
|
||||
(parse-action #'PROD-RHS #'ACTION)))]
|
||||
[(PROD-RHS (PREC TERM) ACTION)
|
||||
(identifier? #'TERM)
|
||||
(let ([p (parse-prod #'PROD-RHS)])
|
||||
(make-prod
|
||||
nt
|
||||
p
|
||||
#f
|
||||
(term-prec
|
||||
(cond
|
||||
[(hash-ref term-table (syntax->datum #'TERM) #f)]
|
||||
[else (raise-syntax-error
|
||||
'parser-production-rhs
|
||||
(format
|
||||
"unrecognized terminal ~a in precedence declaration"
|
||||
(syntax->datum #'TERM))
|
||||
#'TERM)]))
|
||||
(parse-action #'PROD-RHS #'ACTION)))]
|
||||
[_ (raise-syntax-error
|
||||
'parser-production-rhs
|
||||
"production must have form [(symbol ...) expression] or [(symbol ...) (prec symbol) expression]"
|
||||
prod-so)]))
|
||||
|
||||
;; parse-prod-for-nt: syntax-object -> production list
|
||||
(define (parse-prods-for-nt prods-so)
|
||||
(syntax-case prods-so ()
|
||||
[(NT PRODUCTIONS ...)
|
||||
(positive? (length (syntax->list #'(PRODUCTIONS ...))))
|
||||
(let ([nt (hash-ref non-term-table (syntax->datum #'NT))])
|
||||
(map (λ (p) (parse-prod+action nt p)) (syntax->list #'(PRODUCTIONS ...))))]
|
||||
[_ (raise-syntax-error
|
||||
'parser-productions
|
||||
"A production for a non-terminal must be (non-term right-hand-side ...) with at least 1 right hand side"
|
||||
prods-so)]))
|
||||
|
||||
(for ([sstx (in-list start)]
|
||||
[ssym (in-list start-syms)]
|
||||
#:unless (memq ssym list-of-non-terms))
|
||||
(raise-syntax-error
|
||||
'parser-start
|
||||
(format "Start symbol ~a not defined as a non-terminal" ssym)
|
||||
sstx))
|
||||
|
||||
(define starts (map (λ (x) (make-non-term (gensym) #f)) start-syms))
|
||||
(define end-non-terms (map (λ (x) (make-non-term (gensym) #f)) start-syms))
|
||||
(define parsed-prods (map parse-prods-for-nt (syntax->list prods)))
|
||||
(define start-prods (for/list ([start (in-list starts)]
|
||||
[end-non-term (in-list end-non-terms)])
|
||||
(list (make-prod start (vector end-non-term) #f #f #'values))))
|
||||
(define new-prods
|
||||
(append start-prods
|
||||
(for/list ([end-nt (in-list end-non-terms)]
|
||||
[start-sym (in-list start-syms)])
|
||||
(for/list ([end (in-list end-terms)])
|
||||
(make-prod end-nt
|
||||
(vector
|
||||
(hash-ref non-term-table start-sym)
|
||||
(hash-ref term-table end))
|
||||
#f
|
||||
#f
|
||||
#'values)))
|
||||
parsed-prods))
|
||||
|
||||
(make-object grammar%
|
||||
new-prods
|
||||
(map car start-prods)
|
||||
terms
|
||||
(append starts (append end-non-terms non-terms))
|
||||
(map (λ (term-name) (hash-ref term-table term-name)) end-terms)))
|
||||
@ -0,0 +1,252 @@
|
||||
#lang racket/base
|
||||
(require "lr0.rkt"
|
||||
"grammar.rkt"
|
||||
racket/list
|
||||
racket/class)
|
||||
|
||||
;; Compute LALR lookaheads from DeRemer and Pennello 1982
|
||||
|
||||
(provide compute-LA)
|
||||
|
||||
;; compute-DR: LR0-automaton * grammar -> (trans-key -> term set)
|
||||
;; computes for each state, non-term transition pair, the terminals
|
||||
;; which can transition out of the resulting state
|
||||
;; output term set is represented in bit-vector form
|
||||
(define ((compute-DR a g) tk)
|
||||
(define r (send a run-automaton (trans-key-st tk) (trans-key-gs tk)))
|
||||
(term-list->bit-vector
|
||||
(filter (λ (term) (send a run-automaton r term)) (send g get-terms))))
|
||||
|
||||
;; compute-reads:
|
||||
;; LR0-automaton * grammar -> (trans-key -> trans-key list)
|
||||
(define (compute-reads a g)
|
||||
(define nullable-non-terms (filter (λ (nt) (send g nullable-non-term? nt)) (send g get-non-terms)))
|
||||
(λ (tk)
|
||||
(define r (send a run-automaton (trans-key-st tk) (trans-key-gs tk)))
|
||||
(for/list ([non-term (in-list nullable-non-terms)]
|
||||
#:when (send a run-automaton r non-term))
|
||||
(make-trans-key r non-term))))
|
||||
|
||||
;; compute-read: LR0-automaton * grammar -> (trans-key -> term set)
|
||||
;; output term set is represented in bit-vector form
|
||||
(define (compute-read a g)
|
||||
(define dr (compute-DR a g))
|
||||
(define reads (compute-reads a g))
|
||||
(digraph-tk->terml (send a get-mapped-non-term-keys)
|
||||
reads
|
||||
dr
|
||||
(send a get-num-states)))
|
||||
;; returns the list of all k such that state k transitions to state start on the
|
||||
;; transitions in rhs (in order)
|
||||
(define (run-lr0-backward a rhs dot-pos start num-states)
|
||||
(let loop ([states (list start)]
|
||||
[i (sub1 dot-pos)])
|
||||
(cond
|
||||
[(< i 0) states]
|
||||
[else (loop (send a run-automaton-back states (vector-ref rhs i))
|
||||
(sub1 i))])))
|
||||
|
||||
;; prod->items-for-include: grammar * prod * non-term -> lr0-item list
|
||||
;; returns the list of all (B -> beta . nt gamma) such that prod = (B -> beta nt gamma)
|
||||
;; and gamma =>* epsilon
|
||||
(define (prod->items-for-include g prod nt)
|
||||
(define rhs (prod-rhs prod))
|
||||
(define rhs-l (vector-length rhs))
|
||||
(append (if (and (> rhs-l 0) (eq? nt (vector-ref rhs (sub1 rhs-l))))
|
||||
(list (make-item prod (sub1 rhs-l)))
|
||||
null)
|
||||
(let loop ([i (sub1 rhs-l)])
|
||||
(cond
|
||||
[(and (> i 0)
|
||||
(non-term? (vector-ref rhs i))
|
||||
(send g nullable-non-term? (vector-ref rhs i)))
|
||||
(if (eq? nt (vector-ref rhs (sub1 i)))
|
||||
(cons (make-item prod (sub1 i))
|
||||
(loop (sub1 i)))
|
||||
(loop (sub1 i)))]
|
||||
[else null]))))
|
||||
|
||||
;; prod-list->items-for-include: grammar * prod list * non-term -> lr0-item list
|
||||
;; return the list of all (B -> beta . nt gamma) such that (B -> beta nt gamma) in prod-list
|
||||
;; and gamma =>* epsilon
|
||||
(define (prod-list->items-for-include g prod-list nt)
|
||||
(apply append (map (λ (prod) (prod->items-for-include g prod nt)) prod-list)))
|
||||
|
||||
;; comput-includes: lr0-automaton * grammar -> (trans-key -> trans-key list)
|
||||
(define (compute-includes a g)
|
||||
(define num-states (send a get-num-states))
|
||||
(define items-for-input-nt (make-vector (send g get-num-non-terms) null))
|
||||
(for ([input-nt (in-list (send g get-non-terms))])
|
||||
(vector-set! items-for-input-nt (non-term-index input-nt)
|
||||
(prod-list->items-for-include g (send g get-prods) input-nt)))
|
||||
(λ (tk)
|
||||
(define goal-state (trans-key-st tk))
|
||||
(define non-term (trans-key-gs tk))
|
||||
(define items (vector-ref items-for-input-nt (non-term-index non-term)))
|
||||
(trans-key-list-remove-dups
|
||||
(apply append
|
||||
(for/list ([item (in-list items)])
|
||||
(define prod (item-prod item))
|
||||
(define rhs (prod-rhs prod))
|
||||
(define lhs (prod-lhs prod))
|
||||
(map (λ (state) (make-trans-key state lhs))
|
||||
(run-lr0-backward a
|
||||
rhs
|
||||
(item-dot-pos item)
|
||||
goal-state
|
||||
num-states)))))))
|
||||
|
||||
;; compute-lookback: lr0-automaton * grammar -> (kernel * proc -> trans-key list)
|
||||
(define (compute-lookback a g)
|
||||
(define num-states (send a get-num-states))
|
||||
(λ (state prod)
|
||||
(map (λ (k) (make-trans-key k (prod-lhs prod)))
|
||||
(run-lr0-backward a (prod-rhs prod) (vector-length (prod-rhs prod)) state num-states))))
|
||||
|
||||
;; compute-follow: LR0-automaton * grammar -> (trans-key -> term set)
|
||||
;; output term set is represented in bit-vector form
|
||||
(define (compute-follow a g includes)
|
||||
(define read (compute-read a g))
|
||||
(digraph-tk->terml (send a get-mapped-non-term-keys)
|
||||
includes
|
||||
read
|
||||
(send a get-num-states)))
|
||||
|
||||
;; compute-LA: LR0-automaton * grammar -> kernel * prod -> term set
|
||||
;; output term set is represented in bit-vector form
|
||||
(define (compute-LA a g)
|
||||
(define includes (compute-includes a g))
|
||||
(define lookback (compute-lookback a g))
|
||||
(define follow (compute-follow a g includes))
|
||||
(λ (k p)
|
||||
(define l (lookback k p))
|
||||
(define f (map follow l))
|
||||
(apply bitwise-ior (cons 0 f))))
|
||||
|
||||
|
||||
(define (print-DR dr a g)
|
||||
(print-input-st-sym dr "DR" a g print-output-terms))
|
||||
(define (print-Read Read a g)
|
||||
(print-input-st-sym Read "Read" a g print-output-terms))
|
||||
(define (print-includes i a g)
|
||||
(print-input-st-sym i "includes" a g print-output-st-nt))
|
||||
(define (print-lookback l a g)
|
||||
(print-input-st-prod l "lookback" a g print-output-st-nt))
|
||||
(define (print-follow f a g)
|
||||
(print-input-st-sym f "follow" a g print-output-terms))
|
||||
(define (print-LA l a g)
|
||||
(print-input-st-prod l "LA" a g print-output-terms))
|
||||
|
||||
(define (print-input-st-sym f name a g print-output)
|
||||
(printf "~a:\n" name)
|
||||
(send a for-each-state
|
||||
(λ (state)
|
||||
(for-each
|
||||
(λ (non-term)
|
||||
(let ([res (f (make-trans-key state non-term))])
|
||||
(when (not (null? res))
|
||||
(printf "~a(~a, ~a) = ~a\n"
|
||||
name
|
||||
state
|
||||
(gram-sym-symbol non-term)
|
||||
(print-output res)))))
|
||||
(send g get-non-terms))))
|
||||
(newline))
|
||||
|
||||
(define (print-input-st-prod f name a g print-output)
|
||||
(printf "~a:\n" name)
|
||||
(send a for-each-state
|
||||
(λ (state)
|
||||
(for-each
|
||||
(λ (non-term)
|
||||
(for-each
|
||||
(λ (prod)
|
||||
(let ([res (f state prod)])
|
||||
(when (not (null? res))
|
||||
(printf "~a(~a, ~a) = ~a\n"
|
||||
name
|
||||
(kernel-index state)
|
||||
(prod-index prod)
|
||||
(print-output res)))))
|
||||
(send g get-prods-for-non-term non-term)))
|
||||
(send g get-non-terms)))))
|
||||
|
||||
(define (print-output-terms r)
|
||||
(map gram-sym-symbol r))
|
||||
|
||||
(define (print-output-st-nt r)
|
||||
(map (λ (p) (list (kernel-index (trans-key-st p)) (gram-sym-symbol (trans-key-gs p)))) r))
|
||||
|
||||
;; init-tk-map : int -> (vectorof hashtable?)
|
||||
(define (init-tk-map n)
|
||||
(define v (make-vector n #f))
|
||||
(let loop ([i (sub1 (vector-length v))])
|
||||
(when (>= i 0)
|
||||
(vector-set! v i (make-hasheq))
|
||||
(loop (sub1 i))))
|
||||
v)
|
||||
|
||||
;; lookup-tk-map : (vectorof (symbol? int hashtable)) -> trans-key? -> int
|
||||
(define ((lookup-tk-map map) tk)
|
||||
(define st (trans-key-st tk))
|
||||
(define gs (trans-key-gs tk))
|
||||
(hash-ref (vector-ref map (kernel-index st))
|
||||
(gram-sym-symbol gs)
|
||||
(λ () 0)))
|
||||
|
||||
;; add-tk-map : (vectorof (symbol? int hashtable)) -> trans-key int ->
|
||||
(define ((add-tk-map map) tk v)
|
||||
(define st (trans-key-st tk))
|
||||
(define gs (trans-key-gs tk))
|
||||
(hash-set! (vector-ref map (kernel-index st))
|
||||
(gram-sym-symbol gs)
|
||||
v))
|
||||
|
||||
;; digraph-tk->terml:
|
||||
;; (trans-key list) * (trans-key -> trans-key list) * (trans-key -> term list) * int * int * int
|
||||
;; -> (trans-key -> term list)
|
||||
;; DeRemer and Pennello 1982
|
||||
;; Computes (f x) = (f- x) union Union{(f y) | y in (edges x)}
|
||||
;; A specialization of digraph in the file graph.rkt
|
||||
(define (digraph-tk->terml nodes edges f- num-states)
|
||||
;; Will map elements of trans-key to term sets represented as bit vectors
|
||||
(define results (init-tk-map num-states))
|
||||
|
||||
;; Maps elements of trans-keys to integers.
|
||||
(define N (init-tk-map num-states))
|
||||
|
||||
(define get-N (lookup-tk-map N))
|
||||
(define set-N (add-tk-map N))
|
||||
(define get-f (lookup-tk-map results))
|
||||
(define set-f (add-tk-map results))
|
||||
|
||||
(define stack null)
|
||||
(define (push x) (set! stack (cons x stack)))
|
||||
(define (pop) (begin0
|
||||
(car stack)
|
||||
(set! stack (cdr stack))))
|
||||
(define (depth) (length stack))
|
||||
|
||||
;; traverse: 'a ->
|
||||
(define (traverse x)
|
||||
(push x)
|
||||
(let ([d (depth)])
|
||||
(set-N x d)
|
||||
(set-f x (f- x))
|
||||
(for-each (λ (y)
|
||||
(when (= 0 (get-N y))
|
||||
(traverse y))
|
||||
(set-f x (bitwise-ior (get-f x) (get-f y)))
|
||||
(set-N x (min (get-N x) (get-N y))))
|
||||
(edges x))
|
||||
(when (= d (get-N x))
|
||||
(let loop ([p (pop)])
|
||||
(set-N p +inf.0)
|
||||
(set-f p (get-f x))
|
||||
(unless (equal? x p)
|
||||
(loop (pop)))))))
|
||||
|
||||
(for ([x (in-list nodes)]
|
||||
#:when (zero? (get-N x)))
|
||||
(traverse x))
|
||||
get-f)
|
||||
@ -0,0 +1,54 @@
|
||||
#lang racket/base
|
||||
(require "grammar.rkt")
|
||||
(provide (except-out (all-defined-out) make-reduce make-reduce*)
|
||||
(rename-out [make-reduce* make-reduce]))
|
||||
|
||||
;; An action is
|
||||
;; - (make-shift int)
|
||||
;; - (make-reduce prod runtime-action)
|
||||
;; - (make-accept)
|
||||
;; - (make-goto int)
|
||||
;; - (no-action)
|
||||
;; A reduce contains a runtime-reduce so that sharing of the reduces can
|
||||
;; be easily transferred to sharing of runtime-reduces.
|
||||
|
||||
(define-struct action () #:inspector (make-inspector))
|
||||
(define-struct (shift action) (state) #:inspector (make-inspector))
|
||||
(define-struct (reduce action) (prod runtime-reduce) #:inspector (make-inspector))
|
||||
(define-struct (accept action) () #:inspector (make-inspector))
|
||||
(define-struct (goto action) (state) #:inspector (make-inspector))
|
||||
(define-struct (no-action action) () #:inspector (make-inspector))
|
||||
|
||||
(define (make-reduce* p)
|
||||
(make-reduce p
|
||||
(vector (prod-index p)
|
||||
(gram-sym-symbol (prod-lhs p))
|
||||
(vector-length (prod-rhs p)))))
|
||||
|
||||
;; A runtime-action is
|
||||
;; non-negative-int (shift)
|
||||
;; (vector int symbol int) (reduce)
|
||||
;; 'accept (accept)
|
||||
;; negative-int (goto)
|
||||
;; #f (no-action)
|
||||
|
||||
(define (action->runtime-action a)
|
||||
(cond
|
||||
[(shift? a) (shift-state a)]
|
||||
[(reduce? a) (reduce-runtime-reduce a)]
|
||||
[(accept? a) 'accept]
|
||||
[(goto? a) (- (+ (goto-state a) 1))]
|
||||
[(no-action? a) #f]))
|
||||
|
||||
(define (runtime-shift? x) (and (integer? x) (>= x 0)))
|
||||
(define runtime-reduce? vector?)
|
||||
(define (runtime-accept? x) (eq? x 'accept))
|
||||
(define (runtime-goto? x) (and (integer? x) (< x 0)))
|
||||
|
||||
(define runtime-shift-state values)
|
||||
(define (runtime-reduce-prod-num x) (vector-ref x 0))
|
||||
(define (runtime-reduce-lhs x) (vector-ref x 1))
|
||||
(define (runtime-reduce-rhs-length x) (vector-ref x 2))
|
||||
(define (runtime-goto-state x) (- (+ x 1)))
|
||||
|
||||
|
||||
@ -0,0 +1,103 @@
|
||||
#lang racket/base
|
||||
(require "input-file-parser.rkt"
|
||||
"grammar.rkt"
|
||||
"table.rkt"
|
||||
racket/class
|
||||
racket/contract)
|
||||
(require (for-template racket/base))
|
||||
|
||||
(provide/contract [build-parser (-> string? any/c any/c
|
||||
(listof identifier?)
|
||||
(listof identifier?)
|
||||
(listof identifier?)
|
||||
(or/c syntax? #f)
|
||||
syntax?
|
||||
(values any/c any/c any/c any/c))])
|
||||
|
||||
;; fix-check-syntax : (listof identifier?) (listof identifier?) (listof identifier?)
|
||||
;; (union syntax? false/c) syntax?) -> syntax?
|
||||
(define (fix-check-syntax input-terms start ends assocs prods)
|
||||
(define term-binders (get-term-list input-terms))
|
||||
(define get-term-binder
|
||||
(let ([t (make-hasheq)])
|
||||
(for ([term (in-list term-binders)])
|
||||
(hash-set! t (syntax-e term) term))
|
||||
(λ (x)
|
||||
(define r (hash-ref t (syntax-e x) (λ () #f)))
|
||||
(if r
|
||||
(syntax-local-introduce (datum->syntax r (syntax-e x) x x))
|
||||
x))))
|
||||
(define rhs-list (syntax-case prods ()
|
||||
[((_ RHS ...) ...) (syntax->list #'(RHS ... ...))]))
|
||||
(with-syntax ([(TMP ...) (map syntax-local-introduce term-binders)]
|
||||
[(TERM-GROUP ...)
|
||||
(map (λ (tg)
|
||||
(syntax-property
|
||||
(datum->syntax tg #f)
|
||||
'disappeared-use
|
||||
tg))
|
||||
input-terms)]
|
||||
[(END ...) (map get-term-binder ends)]
|
||||
[(START ...) (map get-term-binder start)]
|
||||
[(BIND ...) (syntax-case prods ()
|
||||
(((BIND _ ...) ...)
|
||||
(syntax->list #'(BIND ...))))]
|
||||
[((BOUND ...) ...)
|
||||
(map (λ (rhs)
|
||||
(syntax-case rhs ()
|
||||
[((BOUND ...) (_ PBOUND) __)
|
||||
(map get-term-binder
|
||||
(cons #'PBOUND (syntax->list #'(BOUND ...))))]
|
||||
[((BOUND ...) _)
|
||||
(map get-term-binder
|
||||
(syntax->list #'(BOUND ...)))]))
|
||||
rhs-list)]
|
||||
[(PREC ...)
|
||||
(if assocs
|
||||
(map get-term-binder
|
||||
(syntax-case assocs ()
|
||||
(((__ TERM ...) ...)
|
||||
(syntax->list #'(TERM ... ...)))))
|
||||
null)])
|
||||
#`(when #f
|
||||
(let ((BIND void) ... (TMP void) ...)
|
||||
(void BOUND ... ... TERM-GROUP ... START ... END ... PREC ...)))))
|
||||
|
||||
(require racket/list "parser-actions.rkt")
|
||||
|
||||
(define (build-parser filename src-pos suppress input-terms start end assocs prods)
|
||||
(define grammar (parse-input input-terms start end assocs prods src-pos))
|
||||
(define table (build-table grammar filename suppress))
|
||||
(define all-tokens (make-hasheq))
|
||||
(define actions-code `(vector ,@(map prod-action (send grammar get-prods))))
|
||||
|
||||
(for ([term (in-list (send grammar get-terms))])
|
||||
(hash-set! all-tokens (gram-sym-symbol term) #t))
|
||||
|
||||
#;(let ((num-states (vector-length table))
|
||||
(num-gram-syms (+ (send grammar get-num-terms)
|
||||
(send grammar get-num-non-terms)))
|
||||
(num-ht-entries (apply + (map length (vector->list table))))
|
||||
(num-reduces
|
||||
(let ((ht (make-hasheq)))
|
||||
(for-each
|
||||
(λ (x)
|
||||
(when (reduce? x)
|
||||
(hash-set! ht x #t)))
|
||||
(map cdr (apply append (vector->list table))))
|
||||
(length (hash-table-map ht void)))))
|
||||
(printf "~a states, ~a grammar symbols, ~a hash-table entries, ~a reduces\n"
|
||||
num-states num-gram-syms num-ht-entries num-reduces)
|
||||
(printf "~a -- ~aKB, previously ~aKB\n"
|
||||
(/ (+ 2 num-states
|
||||
(* 4 num-states) (* 2 1.5 num-ht-entries)
|
||||
(* 5 num-reduces)) 256.0)
|
||||
(/ (+ 2 num-states
|
||||
(* 4 num-states) (* 2 2.3 num-ht-entries)
|
||||
(* 5 num-reduces)) 256.0)
|
||||
(/ (+ 2 (* num-states num-gram-syms) (* 5 num-reduces)) 256.0)))
|
||||
(values table
|
||||
all-tokens
|
||||
actions-code
|
||||
(fix-check-syntax input-terms start end assocs prods)))
|
||||
|
||||
@ -0,0 +1,264 @@
|
||||
#lang racket/base
|
||||
(require "grammar.rkt"
|
||||
"lr0.rkt"
|
||||
"lalr.rkt"
|
||||
"parser-actions.rkt"
|
||||
racket/contract
|
||||
racket/list
|
||||
racket/class)
|
||||
|
||||
;; Routine to build the LALR table
|
||||
|
||||
|
||||
(define (is-a-grammar%? x) (is-a? x grammar%))
|
||||
(provide/contract
|
||||
(build-table (-> is-a-grammar%? string? any/c
|
||||
(vectorof (listof (cons/c (or/c term? non-term?) action?))))))
|
||||
|
||||
;; A parse-table is (vectorof (listof (cons/c gram-sym? action)))
|
||||
;; A grouped-parse-table is (vectorof (listof (cons/c gram-sym? (listof action))))
|
||||
|
||||
;; make-parse-table : int -> parse-table
|
||||
(define (make-parse-table num-states)
|
||||
(make-vector num-states null))
|
||||
|
||||
;; table-add!: parse-table nat symbol action ->
|
||||
(define (table-add! table state-index symbol val)
|
||||
(vector-set! table state-index (cons (cons symbol val)
|
||||
(vector-ref table state-index))))
|
||||
|
||||
;; group-table : parse-table -> grouped-parse-table
|
||||
(define (group-table table)
|
||||
(list->vector
|
||||
(for/list ([state-entry (in-list (vector->list table))])
|
||||
(define ht (make-hasheq))
|
||||
(for* ([gs/actions (in-list state-entry)]
|
||||
[group (in-value (hash-ref ht (car gs/actions) (λ () null)))]
|
||||
#:unless (member (cdr gs/actions) group))
|
||||
(hash-set! ht (car gs/actions) (cons (cdr gs/actions) group)))
|
||||
(hash-map ht cons))))
|
||||
|
||||
;; table-map : (vectorof (listof (cons/c gram-sym? X))) (gram-sym? X -> Y) ->
|
||||
;; (vectorof (listof (cons/c gram-sym? Y)))
|
||||
(define (table-map f table)
|
||||
(list->vector
|
||||
(for/list ([state-entry (in-list (vector->list table))])
|
||||
(for/list ([gs/X (in-list state-entry)])
|
||||
(cons (car gs/X) (f (car gs/X) (cdr gs/X)))))))
|
||||
|
||||
(define (bit-vector-for-each f bv)
|
||||
(let loop ([bv bv] [number 0])
|
||||
(cond
|
||||
[(zero? bv) (void)]
|
||||
[(= 1 (bitwise-and 1 bv))
|
||||
(f number)
|
||||
(loop (arithmetic-shift bv -1) (add1 number))]
|
||||
[else (loop (arithmetic-shift bv -1) (add1 number))])))
|
||||
|
||||
|
||||
;; print-entry: symbol action output-port ->
|
||||
;; prints the action a for lookahead sym to the given port
|
||||
(define (print-entry sym a port)
|
||||
(define s "\t~a\t\t\t\t\t~a\t~a\n")
|
||||
(cond
|
||||
[(shift? a) (fprintf port s sym "shift" (shift-state a))]
|
||||
[(reduce? a) (fprintf port s sym "reduce" (prod-index (reduce-prod a)))]
|
||||
[(accept? a) (fprintf port s sym "accept" "")]
|
||||
[(goto? a) (fprintf port s sym "goto" (goto-state a))]))
|
||||
|
||||
|
||||
;; count: ('a -> bool) * 'a list -> num
|
||||
;; counts the number of elements in list that satisfy pred
|
||||
(define (count pred list)
|
||||
(cond
|
||||
[(null? list) 0]
|
||||
[(pred (car list)) (+ 1 (count pred (cdr list)))]
|
||||
[else (count pred (cdr list))]))
|
||||
|
||||
;; display-parser: LR0-automaton grouped-parse-table (listof prod?) output-port ->
|
||||
;; Prints out the parser given by table.
|
||||
(define (display-parser a grouped-table prods port)
|
||||
(define SR-conflicts 0)
|
||||
(define RR-conflicts 0)
|
||||
(for ([prod (in-list prods)])
|
||||
(fprintf port
|
||||
"~a\t~a\t=\t~a\n"
|
||||
(prod-index prod)
|
||||
(gram-sym-symbol (prod-lhs prod))
|
||||
(map gram-sym-symbol (vector->list (prod-rhs prod)))))
|
||||
|
||||
(send a for-each-state
|
||||
(λ (state)
|
||||
(fprintf port "State ~a\n" (kernel-index state))
|
||||
(for ([item (in-list (kernel-items state))])
|
||||
(fprintf port "\t~a\n" (item->string item)))
|
||||
(newline port)
|
||||
(for ([gs/action (in-list (vector-ref grouped-table (kernel-index state)))])
|
||||
(define sym (gram-sym-symbol (car gs/action)))
|
||||
(define act (cdr gs/action))
|
||||
(cond
|
||||
[(null? act) (void)]
|
||||
[(null? (cdr act))
|
||||
(print-entry sym (car act) port)]
|
||||
[else
|
||||
(fprintf port "begin conflict:\n")
|
||||
(when (> (count reduce? act) 1)
|
||||
(set! RR-conflicts (add1 RR-conflicts)))
|
||||
(when (> (count shift? act) 0)
|
||||
(set! SR-conflicts (add1 SR-conflicts)))
|
||||
(map (λ (x) (print-entry sym x port)) act)
|
||||
(fprintf port "end conflict\n")]))
|
||||
(newline port)))
|
||||
|
||||
(when (> SR-conflicts 0)
|
||||
(fprintf port "~a shift/reduce conflict~a\n"
|
||||
SR-conflicts
|
||||
(if (= SR-conflicts 1) "" "s")))
|
||||
(when (> RR-conflicts 0)
|
||||
(fprintf port "~a reduce/reduce conflict~a\n"
|
||||
RR-conflicts
|
||||
(if (= RR-conflicts 1) "" "s"))))
|
||||
|
||||
;; resolve-conflict : (listof action?) -> action? bool bool
|
||||
(define (resolve-conflict actions)
|
||||
(cond
|
||||
[(null? actions) (values (make-no-action) #f #f)]
|
||||
[(null? (cdr actions)) (values (car actions) #f #f)]
|
||||
[else
|
||||
(define SR-conflict? (> (count shift? actions) 0))
|
||||
(define RR-conflict? (> (count reduce? actions) 1))
|
||||
(let loop ((current-guess #f)
|
||||
(rest actions))
|
||||
(cond
|
||||
[(null? rest) (values current-guess SR-conflict? RR-conflict?)]
|
||||
[(shift? (car rest)) (values (car rest) SR-conflict? RR-conflict?)]
|
||||
[(not current-guess) (loop (car rest) (cdr rest))]
|
||||
[(and (reduce? (car rest))
|
||||
(< (prod-index (reduce-prod (car rest)))
|
||||
(prod-index (reduce-prod current-guess))))
|
||||
(loop (car rest) (cdr rest))]
|
||||
[(accept? (car rest))
|
||||
(eprintf "accept/reduce or accept/shift conflicts. Check the grammar for useless cycles of productions\n")
|
||||
(loop current-guess (cdr rest))]
|
||||
[else (loop current-guess (cdr rest))]))]))
|
||||
|
||||
;; resolve-conflicts : grouped-parse-table bool -> parse-table
|
||||
(define (resolve-conflicts grouped-table suppress)
|
||||
(define SR-conflicts 0)
|
||||
(define RR-conflicts 0)
|
||||
(define table (table-map
|
||||
(λ (gs actions)
|
||||
(let-values ([(action SR? RR?)
|
||||
(resolve-conflict actions)])
|
||||
(when SR?
|
||||
(set! SR-conflicts (add1 SR-conflicts)))
|
||||
(when RR?
|
||||
(set! RR-conflicts (add1 RR-conflicts)))
|
||||
action))
|
||||
grouped-table))
|
||||
(unless suppress
|
||||
(when (> SR-conflicts 0)
|
||||
(eprintf "~a shift/reduce conflict~a\n"
|
||||
SR-conflicts
|
||||
(if (= SR-conflicts 1) "" "s")))
|
||||
(when (> RR-conflicts 0)
|
||||
(eprintf "~a reduce/reduce conflict~a\n"
|
||||
RR-conflicts
|
||||
(if (= RR-conflicts 1) "" "s"))))
|
||||
table)
|
||||
|
||||
|
||||
;; resolve-sr-conflict : (listof action) (union int #f) -> (listof action)
|
||||
;; Resolves a single shift-reduce conflict, if precedences are in place.
|
||||
(define (resolve-sr-conflict/prec actions shift-prec)
|
||||
(define shift (if (shift? (car actions))
|
||||
(car actions)
|
||||
(cadr actions)))
|
||||
(define reduce (if (shift? (car actions))
|
||||
(cadr actions)
|
||||
(car actions)))
|
||||
(define reduce-prec (prod-prec (reduce-prod reduce)))
|
||||
(cond
|
||||
[(and shift-prec reduce-prec)
|
||||
(cond
|
||||
[(< (prec-num shift-prec) (prec-num reduce-prec))
|
||||
(list reduce)]
|
||||
[(> (prec-num shift-prec) (prec-num reduce-prec))
|
||||
(list shift)]
|
||||
[(eq? 'left (prec-assoc shift-prec))
|
||||
(list reduce)]
|
||||
[(eq? 'right (prec-assoc shift-prec))
|
||||
(list shift)]
|
||||
[else null])]
|
||||
[else actions]))
|
||||
|
||||
|
||||
;; resolve-prec-conflicts : parse-table -> grouped-parse-table
|
||||
(define (resolve-prec-conflicts table)
|
||||
(table-map
|
||||
(λ (gs actions)
|
||||
(cond
|
||||
[(and (term? gs)
|
||||
(= 2 (length actions))
|
||||
(or (shift? (car actions))
|
||||
(shift? (cadr actions))))
|
||||
(resolve-sr-conflict/prec actions (term-prec gs))]
|
||||
[else actions]))
|
||||
(group-table table)))
|
||||
|
||||
;; build-table: grammar string bool -> parse-table
|
||||
(define (build-table g file suppress)
|
||||
(define a (build-lr0-automaton g))
|
||||
(define term-vector (list->vector (send g get-terms)))
|
||||
(define end-terms (send g get-end-terms))
|
||||
(define table (make-parse-table (send a get-num-states)))
|
||||
(define get-lookahead (compute-LA a g))
|
||||
(define reduce-cache (make-hash))
|
||||
(for ([trans-key/state (in-list (send a get-transitions))])
|
||||
(define from-state-index (kernel-index (trans-key-st (car trans-key/state))))
|
||||
(define gs (trans-key-gs (car trans-key/state)))
|
||||
(define to-state (cdr trans-key/state))
|
||||
|
||||
(table-add! table from-state-index gs
|
||||
(cond
|
||||
((non-term? gs)
|
||||
(make-goto (kernel-index to-state)))
|
||||
((member gs end-terms)
|
||||
(make-accept))
|
||||
(else
|
||||
(make-shift
|
||||
(kernel-index to-state))))))
|
||||
(send a for-each-state
|
||||
(λ (state)
|
||||
(for ([item (in-list (append (hash-ref (send a get-epsilon-trans) state (λ () null))
|
||||
(filter (λ (item)
|
||||
(not (move-dot-right item)))
|
||||
(kernel-items state))))])
|
||||
(let ([item-prod (item-prod item)])
|
||||
(bit-vector-for-each
|
||||
(λ (term-index)
|
||||
(unless (start-item? item)
|
||||
(let ((r (hash-ref reduce-cache item-prod
|
||||
(λ ()
|
||||
(let ((r (make-reduce item-prod)))
|
||||
(hash-set! reduce-cache item-prod r)
|
||||
r)))))
|
||||
(table-add! table
|
||||
(kernel-index state)
|
||||
(vector-ref term-vector term-index)
|
||||
r))))
|
||||
(get-lookahead state item-prod))))))
|
||||
|
||||
(define grouped-table (resolve-prec-conflicts table))
|
||||
(unless (string=? file "")
|
||||
(with-handlers [(exn:fail:filesystem?
|
||||
(λ (e)
|
||||
(eprintf
|
||||
"Cannot write debug output to file \"~a\": ~a\n"
|
||||
file
|
||||
(exn-message e))))]
|
||||
(call-with-output-file file
|
||||
(λ (port)
|
||||
(display-parser a grouped-table (send g get-prods) port))
|
||||
#:exists 'truncate)))
|
||||
(resolve-conflicts grouped-table suppress))
|
||||
@ -0,0 +1,71 @@
|
||||
#lang racket/base
|
||||
(require (prefix-in rl: racket/list)
|
||||
"../private-lex/token-syntax.rkt")
|
||||
|
||||
;; General helper routines
|
||||
(provide duplicate-list? remove-duplicates overlap? vector-andmap display-yacc)
|
||||
|
||||
(define (vector-andmap pred vec)
|
||||
(for/and ([item (in-vector vec)])
|
||||
(pred vec)))
|
||||
|
||||
;; duplicate-list?: symbol list -> #f | symbol
|
||||
;; returns a symbol that exists twice in l, or false if no such symbol
|
||||
;; exists
|
||||
(define (duplicate-list? syms)
|
||||
(rl:check-duplicates syms eq?))
|
||||
|
||||
;; remove-duplicates: syntax-object list -> syntax-object list
|
||||
;; removes the duplicates from the lists
|
||||
(define (remove-duplicates syms)
|
||||
(rl:remove-duplicates syms equal? #:key syntax->datum))
|
||||
|
||||
;; overlap?: symbol list * symbol list -> #f | symbol
|
||||
;; Returns an symbol in l1 intersect l2, or #f is no such symbol exists
|
||||
(define (overlap? syms1 syms2)
|
||||
(for/first ([sym1 (in-list syms1)]
|
||||
#:when (memq sym1 syms2))
|
||||
sym1))
|
||||
|
||||
|
||||
(define (display-yacc grammar tokens start precs port)
|
||||
(let-syntax ([p (syntax-rules ()
|
||||
((_ args ...) (fprintf port args ...)))])
|
||||
(let* ([tokens (map syntax-local-value tokens)]
|
||||
[eterms (filter e-terminals-def? tokens)]
|
||||
[terms (filter terminals-def? tokens)]
|
||||
[term-table (make-hasheq)]
|
||||
[display-rhs
|
||||
(λ (rhs)
|
||||
(for ([sym (in-list (car rhs))])
|
||||
(p "~a " (hash-ref term-table sym (λ () sym))))
|
||||
(when (= 3 (length rhs))
|
||||
(p "%prec ~a" (cadadr rhs)))
|
||||
(p "\n"))])
|
||||
(for* ([t (in-list eterms)]
|
||||
[t (in-list (syntax->datum (e-terminals-def-t t)))])
|
||||
(hash-set! term-table t (format "'~a'" t)))
|
||||
(for* ([t (in-list terms)]
|
||||
[t (in-list (syntax->datum (terminals-def-t t)))])
|
||||
(p "%token ~a\n" t)
|
||||
(hash-set! term-table t (format "~a" t)))
|
||||
(when precs
|
||||
(for ([prec (in-list precs)])
|
||||
(p "%~a " (car prec))
|
||||
(for ([tok (in-list (cdr prec))])
|
||||
(p " ~a" (hash-ref term-table tok)))
|
||||
(p "\n")))
|
||||
(p "%start ~a\n" start)
|
||||
(p "%%\n")
|
||||
(for ([prod (in-list grammar)])
|
||||
(define nt (car prod))
|
||||
(p "~a: " nt)
|
||||
(display-rhs (cadr prod))
|
||||
(for ([rhs (in-list (cddr prod))])
|
||||
(p "| ")
|
||||
(display-rhs rhs))
|
||||
(p ";\n"))
|
||||
(p "%%\n"))))
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,130 @@
|
||||
#lang racket/base
|
||||
(require br-parser-tools/lex
|
||||
(prefix-in : br-parser-tools/lex-sre)
|
||||
br-parser-tools/yacc
|
||||
syntax/readerr
|
||||
racket/list)
|
||||
(provide trans)
|
||||
|
||||
(define match-double-string
|
||||
(lexer
|
||||
[(:+ (:~ #\" #\\)) (append (string->list lexeme)
|
||||
(match-double-string input-port))]
|
||||
[(:: #\\ any-char) (cons (string-ref lexeme 1) (match-double-string input-port))]
|
||||
[#\" null]))
|
||||
|
||||
(define match-single-string
|
||||
(lexer
|
||||
[(:+ (:~ #\' #\\)) (append (string->list lexeme)
|
||||
(match-single-string input-port))]
|
||||
[(:: #\\ any-char) (cons (string-ref lexeme 1) (match-single-string input-port))]
|
||||
[#\' null]))
|
||||
|
||||
(define-lex-abbrevs
|
||||
[letter (:or (:/ "a" "z") (:/ "A" "Z"))]
|
||||
[digit (:/ "0" "9")]
|
||||
[initial (:or letter (char-set "!$%&*/<=>?^_~@"))]
|
||||
[subsequent (:or initial digit (char-set "+-.@"))]
|
||||
[comment (:: "/*" (complement (:: any-string "*/" any-string)) "*/")])
|
||||
|
||||
(define-empty-tokens x (EOF PIPE |:| SEMI |%%| %prec))
|
||||
(define-tokens y (SYM STRING))
|
||||
|
||||
(define get-token-grammar
|
||||
(lexer-src-pos
|
||||
["%%" '|%%|]
|
||||
[":" (string->symbol lexeme)]
|
||||
["%prec" (string->symbol lexeme)]
|
||||
[#\| 'PIPE]
|
||||
[(:+ (:or #\newline #\tab " " comment (:: "{" (:* (:~ "}")) "}")))
|
||||
(return-without-pos (get-token-grammar input-port))]
|
||||
[#\; 'SEMI]
|
||||
[#\' (token-STRING (string->symbol (list->string (match-single-string input-port))))]
|
||||
[#\" (token-STRING (string->symbol (list->string (match-double-string input-port))))]
|
||||
[(:: initial (:* subsequent)) (token-SYM (string->symbol lexeme))]))
|
||||
|
||||
(define (parse-grammar enter-term enter-empty-term enter-non-term)
|
||||
(parser
|
||||
(tokens x y)
|
||||
(src-pos)
|
||||
(error (λ (tok-ok tok-name tok-value start-pos end-pos)
|
||||
(raise-read-error
|
||||
(format "Error Parsing YACC grammar at token: ~a with value: ~a" tok-name tok-value)
|
||||
(file-path)
|
||||
(position-line start-pos)
|
||||
(position-col start-pos)
|
||||
(position-offset start-pos)
|
||||
(- (position-offset end-pos) (position-offset start-pos)))))
|
||||
|
||||
(end |%%|)
|
||||
(start gram)
|
||||
(grammar
|
||||
(gram
|
||||
((production) (list $1))
|
||||
((production gram) (cons $1 $2)))
|
||||
(production
|
||||
((SYM |:| prods SEMI)
|
||||
(begin
|
||||
(enter-non-term $1)
|
||||
(cons $1 $3))))
|
||||
(prods
|
||||
((rhs) (list `(,$1 #f)))
|
||||
((rhs prec) (list `(,$1 ,$2 #f)))
|
||||
((rhs PIPE prods) (cons `(,$1 #f) $3))
|
||||
((rhs prec PIPE prods) (cons `(,$1 ,$2 #f) $4)))
|
||||
(prec
|
||||
((%prec SYM)
|
||||
(begin
|
||||
(enter-term $2)
|
||||
(list 'prec $2)))
|
||||
((%prec STRING)
|
||||
(begin
|
||||
(enter-empty-term $2)
|
||||
(list 'prec $2))))
|
||||
(rhs
|
||||
(() null)
|
||||
((SYM rhs)
|
||||
(begin
|
||||
(enter-term $1)
|
||||
(cons $1 $2)))
|
||||
((STRING rhs)
|
||||
(begin
|
||||
(enter-empty-term $1)
|
||||
(cons $1 $2)))))))
|
||||
|
||||
(define (symbol<? a b)
|
||||
(string<? (symbol->string a) (symbol->string b)))
|
||||
|
||||
(define (trans filename)
|
||||
(define i (open-input-file filename))
|
||||
(define terms (make-hasheq))
|
||||
(define eterms (make-hasheq))
|
||||
(define nterms (make-hasheq))
|
||||
(define (enter-term s)
|
||||
(when (not (hash-ref nterms s (λ () #f)))
|
||||
(hash-set! terms s #t)))
|
||||
(define (enter-empty-term s)
|
||||
(when (not (hash-ref nterms s (λ () #f)))
|
||||
(hash-set! eterms s #t)))
|
||||
(define (enter-non-term s)
|
||||
(hash-remove! terms s)
|
||||
(hash-remove! eterms s)
|
||||
(hash-set! nterms s #t))
|
||||
(port-count-lines! i)
|
||||
(file-path filename)
|
||||
(regexp-match "%%" i)
|
||||
(begin0
|
||||
(let ([gram ((parse-grammar enter-term enter-empty-term enter-non-term)
|
||||
(λ ()
|
||||
(let ((t (get-token-grammar i)))
|
||||
t)))])
|
||||
`(begin
|
||||
(define-tokens t ,(sort (hash-map terms (λ (k v) k)) symbol<?))
|
||||
(define-empty-tokens et ,(sort (hash-map eterms (λ (k v) k)) symbol<?))
|
||||
(parser
|
||||
(start ___)
|
||||
(end ___)
|
||||
(error ___)
|
||||
(tokens t et)
|
||||
(grammar ,@gram))))
|
||||
(close-input-port i)))
|
||||
@ -0,0 +1,334 @@
|
||||
#lang racket/base
|
||||
(require (for-syntax racket/base
|
||||
"private-yacc/parser-builder.rkt"
|
||||
"private-yacc/grammar.rkt"
|
||||
"private-yacc/yacc-helper.rkt"
|
||||
"private-yacc/parser-actions.rkt")
|
||||
"private-lex/token.rkt"
|
||||
"private-yacc/parser-actions.rkt"
|
||||
racket/local
|
||||
racket/pretty
|
||||
syntax/readerr)
|
||||
|
||||
(provide parser)
|
||||
|
||||
|
||||
;; convert-parse-table : (vectorof (listof (cons/c gram-sym? action?))) ->
|
||||
;; (vectorof (symbol runtime-action hashtable))
|
||||
(define-for-syntax (convert-parse-table table)
|
||||
(for/vector ([state-entry (in-vector table)])
|
||||
(let ([ht (make-hasheq)])
|
||||
(for ([gs/action (in-list state-entry)])
|
||||
(hash-set! ht
|
||||
(gram-sym-symbol (car gs/action))
|
||||
(action->runtime-action (cdr gs/action))))
|
||||
ht)))
|
||||
|
||||
(define-syntax (parser stx)
|
||||
(syntax-case stx ()
|
||||
[(_ ARGS ...)
|
||||
(let ([arg-list (syntax->list #'(ARGS ...))]
|
||||
[src-pos #f]
|
||||
[debug #f]
|
||||
[error #f]
|
||||
[tokens #f]
|
||||
[start #f]
|
||||
[end #f]
|
||||
[precs #f]
|
||||
[suppress #f]
|
||||
[grammar #f]
|
||||
[yacc-output #f])
|
||||
(for ([arg (in-list (syntax->list #'(ARGS ...)))])
|
||||
(syntax-case* arg (debug error tokens start end precs grammar
|
||||
suppress src-pos yacc-output)
|
||||
(λ (a b) (eq? (syntax-e a) (syntax-e b)))
|
||||
[(debug FILENAME)
|
||||
(cond
|
||||
[(not (string? (syntax-e #'FILENAME)))
|
||||
(raise-syntax-error #f "Debugging filename must be a string" stx #'FILENAME)]
|
||||
[debug (raise-syntax-error #f "Multiple debug declarations" stx)]
|
||||
[else (set! debug (syntax-e #'FILENAME))])]
|
||||
[(suppress) (set! suppress #t)]
|
||||
[(src-pos) (set! src-pos #t)]
|
||||
[(error EXPRESSION)
|
||||
(if error
|
||||
(raise-syntax-error #f "Multiple error declarations" stx)
|
||||
(set! error #'EXPRESSION))]
|
||||
[(tokens DEF ...)
|
||||
(begin
|
||||
(when tokens
|
||||
(raise-syntax-error #f "Multiple tokens declarations" stx))
|
||||
(let ((defs (syntax->list #'(DEF ...))))
|
||||
(for ([d (in-list defs)]
|
||||
#:unless (identifier? d))
|
||||
(raise-syntax-error #f "Token-group name must be an identifier" stx d))
|
||||
(set! tokens defs)))]
|
||||
[(start symbol ...)
|
||||
(let ([symbols (syntax->list #'(symbol ...))])
|
||||
(for ([sym (in-list symbols)]
|
||||
#:unless (identifier? sym))
|
||||
(raise-syntax-error #f "Start symbol must be a symbol" stx sym))
|
||||
(when start
|
||||
(raise-syntax-error #f "Multiple start declarations" stx))
|
||||
(when (null? symbols)
|
||||
(raise-syntax-error #f "Missing start symbol" stx arg))
|
||||
(set! start symbols))]
|
||||
[(end SYMBOLS ...)
|
||||
(let ((symbols (syntax->list #'(SYMBOLS ...))))
|
||||
(for ([sym (in-list symbols)]
|
||||
#:unless (identifier? sym))
|
||||
(raise-syntax-error #f "End token must be a symbol" stx sym))
|
||||
(let ([d (duplicate-list? (map syntax-e symbols))])
|
||||
(when d
|
||||
(raise-syntax-error #f (format "Duplicate end token definition for ~a" d) stx arg))
|
||||
(when (null? symbols)
|
||||
(raise-syntax-error #f "end declaration must contain at least 1 token" stx arg))
|
||||
(when end
|
||||
(raise-syntax-error #f "Multiple end declarations" stx))
|
||||
(set! end symbols)))]
|
||||
[(precs DECLS ...)
|
||||
(if precs
|
||||
(raise-syntax-error #f "Multiple precs declarations" stx)
|
||||
(set! precs (syntax/loc arg (DECLS ...))))]
|
||||
[(grammar PRODS ...)
|
||||
(if grammar
|
||||
(raise-syntax-error #f "Multiple grammar declarations" stx)
|
||||
(set! grammar (syntax/loc arg (PRODS ...))))]
|
||||
[(yacc-output FILENAME)
|
||||
(cond
|
||||
[(not (string? (syntax-e #'FILENAME)))
|
||||
(raise-syntax-error #f "Yacc-output filename must be a string" stx #'FILENAME)]
|
||||
[yacc-output
|
||||
(raise-syntax-error #f "Multiple yacc-output declarations" stx)]
|
||||
[else
|
||||
(set! yacc-output (syntax-e #'FILENAME))])]
|
||||
[_ (raise-syntax-error #f "argument must match (debug filename), (error expression), (tokens def ...), (start non-term), (end tokens ...), (precs decls ...), or (grammar prods ...)" stx arg)]))
|
||||
(unless tokens
|
||||
(raise-syntax-error #f "missing tokens declaration" stx))
|
||||
(unless error
|
||||
(raise-syntax-error #f "missing error declaration" stx))
|
||||
(unless grammar
|
||||
(raise-syntax-error #f "missing grammar declaration" stx))
|
||||
(unless end
|
||||
(raise-syntax-error #f "missing end declaration" stx))
|
||||
(unless start
|
||||
(raise-syntax-error #f "missing start declaration" stx))
|
||||
(let-values ([(table all-term-syms actions check-syntax-fix)
|
||||
(build-parser (if debug debug "")
|
||||
src-pos
|
||||
suppress
|
||||
tokens
|
||||
start
|
||||
end
|
||||
precs
|
||||
grammar)])
|
||||
(when (and yacc-output (not (string=? yacc-output "")))
|
||||
(with-handlers [(exn:fail:filesystem?
|
||||
(λ (e) (eprintf "Cannot write yacc-output to file \"~a\"\n" yacc-output)))]
|
||||
(call-with-output-file yacc-output
|
||||
(λ (port)
|
||||
(display-yacc (syntax->datum grammar)
|
||||
tokens
|
||||
(map syntax->datum start)
|
||||
(and precs (syntax->datum precs))
|
||||
port))
|
||||
#:exists 'truncate)))
|
||||
(with-syntax ([check-syntax-fix check-syntax-fix]
|
||||
[err error]
|
||||
[ends end]
|
||||
[starts start]
|
||||
[debug debug]
|
||||
[table (convert-parse-table table)]
|
||||
[all-term-syms all-term-syms]
|
||||
[actions actions]
|
||||
[src-pos src-pos])
|
||||
#'(begin
|
||||
check-syntax-fix
|
||||
(parser-body debug err (quote starts) (quote ends) table all-term-syms actions src-pos)))))]
|
||||
[_ (raise-syntax-error #f "parser must have the form (parser args ...)" stx)]))
|
||||
|
||||
(define (reduce-stack stack num ret-vals src-pos)
|
||||
(cond
|
||||
[(positive? num)
|
||||
(define top-frame (car stack))
|
||||
(let ([ret-vals (if src-pos
|
||||
(cons (stack-frame-value top-frame)
|
||||
(cons (stack-frame-start-pos top-frame)
|
||||
(cons (stack-frame-end-pos top-frame)
|
||||
ret-vals)))
|
||||
(cons (stack-frame-value top-frame) ret-vals))])
|
||||
(reduce-stack (cdr stack) (sub1 num) ret-vals src-pos))]
|
||||
[else (values stack ret-vals)]))
|
||||
|
||||
;; extract-helper : (symbol or make-token) any any -> symbol any any any
|
||||
(define (extract-helper tok v1 v2)
|
||||
(cond
|
||||
[(symbol? tok) (values tok #f v1 v2)]
|
||||
[(token? tok) (values (real-token-name tok) (real-token-value tok) v1 v2)]
|
||||
[else (raise-argument-error 'parser "(or/c symbol? token?)" 0 tok)]))
|
||||
|
||||
;; well-formed-position-token?: any -> boolean
|
||||
;; Returns true if pt is a position token whose position-token-token
|
||||
;; is itself a token or a symbol.
|
||||
;; This is meant to help raise more precise error messages when
|
||||
;; a tokenizer produces an erroneous position-token wrapped twice.
|
||||
;; (as often happens when omitting return-without-pos).
|
||||
(define (well-formed-token-field? t)
|
||||
(or (symbol? t) (token? t)))
|
||||
|
||||
(define (well-formed-position-token? pt)
|
||||
(and (position-token? pt)
|
||||
(well-formed-token-field? (position-token-token pt))))
|
||||
|
||||
(define (well-formed-srcloc-token? st)
|
||||
(and (srcloc-token? st)
|
||||
(well-formed-token-field? (srcloc-token-token st))))
|
||||
|
||||
;; extract-src-pos : position-token -> symbol any any any
|
||||
(define (extract-src-pos ip)
|
||||
(unless (well-formed-position-token? ip)
|
||||
(raise-argument-error 'parser "well-formed-position-token?" 0 ip))
|
||||
(extract-helper (position-token-token ip)
|
||||
(position-token-start-pos ip)
|
||||
(position-token-end-pos ip)))
|
||||
|
||||
(define (extract-srcloc ip)
|
||||
(unless (well-formed-srcloc-token? ip)
|
||||
(raise-argument-error 'parser "well-formed-srcloc-token?" 0 ip))
|
||||
(define loc (srcloc-token-srcloc ip))
|
||||
(extract-helper (srcloc-token-token ip)
|
||||
(position-token (srcloc-position loc) (srcloc-line loc) (srcloc-column loc))
|
||||
(position-token (+ (srcloc-position loc) (srcloc-span loc)) #f #f)))
|
||||
|
||||
|
||||
;; extract-no-src-pos : (symbol or make-token) -> symbol any any any
|
||||
(define (extract-no-src-pos ip)
|
||||
(extract-helper ip #f #f))
|
||||
|
||||
(define-struct stack-frame (state value start-pos end-pos) #:inspector (make-inspector))
|
||||
|
||||
(define (make-empty-stack i) (list (make-stack-frame i #f #f #f)))
|
||||
|
||||
|
||||
;; The table is a vector that maps each state to a hash-table that maps a
|
||||
;; terminal symbol to either an accept, shift, reduce, or goto structure.
|
||||
; We encode the structures according to the runtime-action data definition in
|
||||
;; parser-actions.rkt
|
||||
(define (parser-body debug? err starts ends table all-term-syms actions src-pos)
|
||||
(local ((define extract
|
||||
(if src-pos
|
||||
extract-src-pos
|
||||
extract-no-src-pos))
|
||||
|
||||
(define (fix-error stack tok val start-pos end-pos get-token)
|
||||
(when debug? (pretty-print stack))
|
||||
(local ((define (remove-input tok val start-pos end-pos)
|
||||
(if (memq tok ends)
|
||||
(raise-read-error "parser: Cannot continue after error"
|
||||
#f #f #f #f #f)
|
||||
(let ([a (find-action stack tok val start-pos end-pos)])
|
||||
(cond
|
||||
[(runtime-shift? a)
|
||||
;; (printf "shift:~a\n" (runtime-shift-state a))
|
||||
(cons (make-stack-frame (runtime-shift-state a)
|
||||
val
|
||||
start-pos
|
||||
end-pos)
|
||||
stack)]
|
||||
[else
|
||||
;; (printf "discard input:~a\n" tok)
|
||||
(let-values ([(tok val start-pos end-pos)
|
||||
(extract (get-token))])
|
||||
(remove-input tok val start-pos end-pos))])))))
|
||||
(let remove-states ()
|
||||
(let ([a (find-action stack 'error #f start-pos end-pos)])
|
||||
(cond
|
||||
[(runtime-shift? a)
|
||||
;; (printf "shift:~a\n" (runtime-shift-state a))
|
||||
(set! stack
|
||||
(cons
|
||||
(make-stack-frame (runtime-shift-state a)
|
||||
#f
|
||||
start-pos
|
||||
end-pos)
|
||||
stack))
|
||||
(remove-input tok val start-pos end-pos)]
|
||||
[else
|
||||
;; (printf "discard state:~a\n" (car stack))
|
||||
(cond
|
||||
[(< (length stack) 2)
|
||||
(raise-read-error "parser: Cannot continue after error"
|
||||
#f #f #f #f #f)]
|
||||
[else
|
||||
(set! stack (cdr stack))
|
||||
(remove-states)])])))))
|
||||
|
||||
(define (find-action stack tok val start-pos end-pos)
|
||||
(unless (hash-ref all-term-syms tok #f)
|
||||
(if src-pos
|
||||
(err #f tok val start-pos end-pos)
|
||||
(err #f tok val))
|
||||
(raise-read-error (format "parser: got token of unknown type ~a" tok)
|
||||
#f #f #f #f #f))
|
||||
(hash-ref (vector-ref table (stack-frame-state (car stack))) tok #f))
|
||||
|
||||
(define ((make-parser start-number) get-token)
|
||||
(unless (and (procedure? get-token)
|
||||
(procedure-arity-includes? get-token 0))
|
||||
(error 'get-token "expected a nullary procedure, got ~e" get-token))
|
||||
(let parsing-loop ([stack (make-empty-stack start-number)]
|
||||
[ip (get-token)])
|
||||
(let-values ([(tok val start-pos end-pos) (extract ip)])
|
||||
(let ([action (find-action stack tok val start-pos end-pos)])
|
||||
(cond
|
||||
[(runtime-shift? action)
|
||||
;; (printf "shift:~a\n" (runtime-shift-state action))
|
||||
(parsing-loop (cons (make-stack-frame (runtime-shift-state action)
|
||||
val
|
||||
start-pos
|
||||
end-pos)
|
||||
stack)
|
||||
(get-token))]
|
||||
[(runtime-reduce? action)
|
||||
;; (printf "reduce:~a\n" (runtime-reduce-prod-num action))
|
||||
(let-values ([(new-stack args)
|
||||
(reduce-stack stack
|
||||
(runtime-reduce-rhs-length action)
|
||||
null
|
||||
src-pos)])
|
||||
(let ([goto
|
||||
(runtime-goto-state
|
||||
(hash-ref
|
||||
(vector-ref table (stack-frame-state (car new-stack)))
|
||||
(runtime-reduce-lhs action)))])
|
||||
(parsing-loop
|
||||
(cons
|
||||
(if src-pos
|
||||
(make-stack-frame
|
||||
goto
|
||||
(apply (vector-ref actions (runtime-reduce-prod-num action)) args)
|
||||
(if (null? args) start-pos (cadr args))
|
||||
(if (null? args)
|
||||
end-pos
|
||||
(list-ref args (- (* (runtime-reduce-rhs-length action) 3) 1))))
|
||||
(make-stack-frame
|
||||
goto
|
||||
(apply (vector-ref actions (runtime-reduce-prod-num action)) args)
|
||||
#f
|
||||
#f))
|
||||
new-stack)
|
||||
ip)))]
|
||||
[(runtime-accept? action)
|
||||
;; (printf "accept\n")
|
||||
(stack-frame-value (car stack))]
|
||||
[else
|
||||
(if src-pos
|
||||
(err #t tok val start-pos end-pos)
|
||||
(err #t tok val))
|
||||
(parsing-loop (fix-error stack tok val start-pos end-pos get-token)
|
||||
(get-token))]))))))
|
||||
(cond
|
||||
[(null? (cdr starts)) (make-parser 0)]
|
||||
[else
|
||||
(for/list ([(l i) (in-indexed starts)])
|
||||
(make-parser i))])))
|
||||
@ -0,0 +1,9 @@
|
||||
#lang info
|
||||
|
||||
(define collection 'multi)
|
||||
(define deps '("scheme-lib"
|
||||
"base"
|
||||
"compatibility-lib"))
|
||||
(define build-deps '("rackunit-lib"))
|
||||
|
||||
(define pkg-desc "implementation (no documentation) part of \"br-parser-tools\"")
|
||||
@ -0,0 +1,11 @@
|
||||
parser-tools
|
||||
Copyright (c) 2010-2014 PLT Design Inc.
|
||||
|
||||
This package is distributed under the GNU Lesser General Public
|
||||
License (LGPL). This means that you can link this package into proprietary
|
||||
applications, provided you follow the rules stated in the LGPL. You
|
||||
can also modify this package; if you distribute a modified version,
|
||||
you must distribute it under the terms of the LGPL, which in
|
||||
particular means that you must release the source code for the
|
||||
modified software. See http://www.gnu.org/copyleft/lesser.html
|
||||
for more information.
|
||||
@ -0,0 +1,12 @@
|
||||
#lang info
|
||||
|
||||
(define collection 'multi)
|
||||
|
||||
(define deps '("br-parser-tools-lib"
|
||||
"br-parser-tools-doc"))
|
||||
(define implies '("br-parser-tools-lib"
|
||||
"br-parser-tools-doc"))
|
||||
|
||||
(define pkg-desc "Lex- and Yacc-style parsing tools")
|
||||
|
||||
(define pkg-authors '(mflatt))
|
||||
Loading…
Reference in New Issue