You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
275 lines
11 KiB
Racket
275 lines
11 KiB
Racket
#lang racket/base
|
|
(require racket/list
|
|
racket/syntax
|
|
yaragg/rules/stx-types
|
|
syntax/id-table
|
|
(prefix-in sat: yaragg/codegen/satisfaction)
|
|
(for-template racket/base
|
|
yaragg/codegen/runtime
|
|
yaragg/private/internal-support))
|
|
|
|
(provide (all-defined-out)
|
|
(for-template (all-from-out yaragg/codegen/runtime
|
|
yaragg/private/internal-support)))
|
|
|
|
;; Given a flattened rule, returns a syntax for the code that
|
|
;; preserves as much source location as possible.
|
|
;;
|
|
;; Each rule is defined to return a list with the following structure:
|
|
;;
|
|
;; stx :== (name (U tokens rule-stx) ...)
|
|
;;
|
|
(define (flat-rule->yacc-rule a-flat-rule)
|
|
(syntax-case a-flat-rule ()
|
|
[(rule-type origin name . clauses)
|
|
(with-syntax ([translated-clauses (for/list ([clause-stx (in-list (syntax->list #'clauses))])
|
|
(translate-clause clause-stx #'name #'origin))])
|
|
#'[name . translated-clauses])]))
|
|
|
|
|
|
|
|
;; translates a single primitive rule clause.
|
|
;; A clause is a simple list of ids, lit, vals, and inferred-id elements.
|
|
;; The action taken depends on the pattern type.
|
|
(define (translate-clause a-clause rule-name/false origin)
|
|
(define translated-patterns
|
|
(let loop ([primitive-patterns (syntax->list a-clause)])
|
|
(cond
|
|
[(empty? primitive-patterns) '()]
|
|
[else
|
|
(cons (syntax-case (first primitive-patterns) (id lit token inferred-id)
|
|
[(id val)
|
|
#'val]
|
|
[(lit val)
|
|
(datum->syntax #f (string->symbol (syntax-e #'val)) #'val)]
|
|
[(token val)
|
|
#'val]
|
|
[(inferred-id val reason)
|
|
#'val])
|
|
(loop (rest primitive-patterns)))])))
|
|
|
|
(define translated-actions
|
|
(for/list ([translated-pattern (in-list translated-patterns)]
|
|
[primitive-pattern (in-list (syntax->list a-clause))]
|
|
[pos (in-naturals 1)])
|
|
(if (eq? (syntax-property primitive-pattern 'hide) 'hide)
|
|
#'null
|
|
(with-syntax ([$X (format-id translated-pattern "$~a" pos)]
|
|
[$X-start-pos (format-id translated-pattern "$~a-start-pos" pos)]
|
|
[$X-end-pos (format-id translated-pattern "$~a-end-pos" pos)])
|
|
(syntax-case primitive-pattern (id lit token inferred-id)
|
|
|
|
;; When a rule usage is inferred, the value of $X is a syntax object
|
|
;; whose head is the name of the inferred rule. We strip that out,
|
|
;; leaving the residue to be absorbed.
|
|
[(inferred-id val reason)
|
|
#'(syntax-case $X ()
|
|
[(inferred-rule-name . rest)
|
|
(syntax->list #'rest)])]
|
|
[(id val)
|
|
;; at this point, the 'hide property is either #f or "splice"
|
|
;; ('hide value is handled at the top of this conditional)
|
|
;; we need to use boolean because a symbol is treated as an identifier.
|
|
;; also we'll separate it into its own property for clarity and test for it in "runtime.rkt"
|
|
#`(list (syntax-property $X 'splice-rh-id #,(and (syntax-property primitive-pattern 'hide) #t)))]
|
|
[(lit val)
|
|
#'(list (atomic-datum->syntax $X $X-start-pos $X-end-pos))]
|
|
[(token val)
|
|
#'(list (atomic-datum->syntax $X $X-start-pos $X-end-pos))])))))
|
|
|
|
(define whole-rule-loc
|
|
(if (empty? translated-patterns)
|
|
#'(list (current-source) #f #f #f #f)
|
|
(with-syntax ([$1-start-pos (datum->syntax (first translated-patterns) '$1-start-pos)]
|
|
[$n-end-pos (format-id (last translated-patterns) "$~a-end-pos" (length translated-patterns))])
|
|
#`(positions->srcloc $1-start-pos $n-end-pos))))
|
|
|
|
;; move 'hide-or-splice-lhs-id property into function because name is datum-ized
|
|
(with-syntax ([(translated-pattern ...) translated-patterns]
|
|
[(translated-action ...) translated-actions])
|
|
#`[(translated-pattern ...)
|
|
(rule-components->syntax '#,rule-name/false translated-action ...
|
|
#:srcloc #,whole-rule-loc
|
|
#:hide-or-splice? #,(syntax-property rule-name/false 'hide-or-splice-lhs-id))]))
|
|
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; collect-token-types: (listof rule-syntax) -> (values (listof identifier) (listof identifier))
|
|
;;
|
|
;; Given a rule, automatically derive the list of implicit and
|
|
;; explicit token types we need to generate.
|
|
;;
|
|
;; Note: EOF is reserved, and will always be included in the list
|
|
;; of explicit token types, though the user is not allow to express it themselves.
|
|
(define (rules-collect-token-types rules)
|
|
(define-values (implicit explicit)
|
|
(for/fold ([implicit '()]
|
|
[explicit (list (datum->syntax (first rules) 'EOF))])
|
|
([a-rule (in-list rules)])
|
|
(syntax-case a-rule (rule)
|
|
[(rule _ a-pattern)
|
|
(let loop ([a-pattern #'a-pattern]
|
|
[implicit implicit]
|
|
[explicit explicit])
|
|
(syntax-case a-pattern (id lit token choice repeat maybe seq EOF)
|
|
[(id val)
|
|
(values implicit explicit)]
|
|
[(lit val)
|
|
(values (cons #'val implicit) explicit)]
|
|
[(token EOF)
|
|
(raise-syntax-error #f "Token EOF is reserved and can not be used in a grammar" #'val)]
|
|
[(token val)
|
|
(values implicit (cons #'val explicit))]
|
|
[(choice . vals)
|
|
(for/fold ([implicit implicit]
|
|
[explicit explicit])
|
|
([v (in-list (syntax->list #'vals))])
|
|
(loop v implicit explicit))]
|
|
[(repeat min max val)
|
|
(loop #'val implicit explicit)]
|
|
[(maybe val)
|
|
(loop #'val implicit explicit)]
|
|
[(seq . vals)
|
|
(for/fold ([implicit implicit]
|
|
[explicit explicit])
|
|
([v (in-list (syntax->list #'vals))])
|
|
(loop v implicit explicit))]))])))
|
|
(values (reverse implicit) (reverse explicit)))
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; rule-id: rule -> identifier-stx
|
|
;; Get the binding id of a rule.
|
|
(define (rule-id a-rule)
|
|
(syntax-case a-rule (rule)
|
|
[(rule id a-pattern)
|
|
#'id]))
|
|
|
|
(define (rule-pattern a-rule)
|
|
(syntax-case a-rule (rule)
|
|
[(rule id a-pattern)
|
|
#'a-pattern]))
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;; check-all-rules-defined!: (listof rule-stx) -> void
|
|
(define (check-all-rules-defined! rules)
|
|
(define table (make-free-id-table))
|
|
;; Pass one: collect all the defined rule names.
|
|
(for ([a-rule (in-list rules)])
|
|
(free-id-table-set! table (rule-id a-rule) #t))
|
|
;; Pass two: check each referenced id, and make sure it's been defined.
|
|
(for* ([a-rule (in-list rules)]
|
|
[referenced-id (in-list (rule-collect-used-ids a-rule))]
|
|
#:unless (free-id-table-ref table referenced-id (λ () #f)))
|
|
(raise-syntax-error #f (format "Rule ~a has no definition" (syntax-e referenced-id))
|
|
referenced-id)))
|
|
|
|
;; check-all-rules-no-duplicates!: (listof rule-stx) -> void
|
|
(define (check-all-rules-no-duplicates! rules)
|
|
(define table (make-free-id-table))
|
|
;; Pass one: collect all the defined rule names.
|
|
(for ([a-rule (in-list rules)])
|
|
(define maybe-other-rule-id (free-id-table-ref table (rule-id a-rule) (λ () #f)))
|
|
(when maybe-other-rule-id
|
|
(raise-syntax-error #f (format "Rule ~a has a duplicate definition" (syntax-e (rule-id a-rule)))
|
|
(rule-id a-rule)
|
|
#f
|
|
(list (rule-id a-rule) maybe-other-rule-id)))
|
|
(free-id-table-set! table (rule-id a-rule) (rule-id a-rule))))
|
|
|
|
|
|
|
|
;; rule-collect-used-ids: rule-stx -> (listof identifier)
|
|
;; Given a rule, extracts a list of identifiers
|
|
(define (rule-collect-used-ids a-rule)
|
|
(syntax-case a-rule (rule)
|
|
[(rule id a-pattern)
|
|
(pattern-collect-used-ids #'a-pattern '())]))
|
|
|
|
;; pattern-collect-used-ids: pattern-stx (listof identifier) -> (listof identifier)
|
|
;; Returns a flat list of rule identifiers referenced in the pattern.
|
|
(define (pattern-collect-used-ids a-pattern acc)
|
|
(let loop ([a-pattern a-pattern]
|
|
[acc acc])
|
|
(syntax-case a-pattern (id lit token choice repeat maybe seq)
|
|
[(id val)
|
|
(cons #'val acc)]
|
|
[(lit val)
|
|
acc]
|
|
[(token val)
|
|
acc]
|
|
[(choice . vals)
|
|
(for/fold ([acc acc])
|
|
([v (in-list (syntax->list #'vals))])
|
|
(loop v acc))]
|
|
[(repeat min max val)
|
|
(loop #'val acc)]
|
|
[(maybe val)
|
|
(loop #'val acc)]
|
|
[(seq . vals)
|
|
(for/fold ([acc acc])
|
|
([v (in-list (syntax->list #'vals))])
|
|
(loop v acc))])))
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; check-all-rules-satisfiable: (listof rule-stx) -> void
|
|
;; Does a simple graph traversal / topological sort-like thing to make sure that, for
|
|
;; any rule, there's some finite sequence of tokens that
|
|
;; satisfies it. If this is not the case, then something horrible
|
|
;; has happened, and we need to tell the user about it.
|
|
;;
|
|
;; NOTE: Assumes all referenced rules have definitions.
|
|
(define (check-all-rules-satisfiable! rules)
|
|
(define toplevel-rule-table
|
|
(make-free-id-table (for/list ([a-rule (in-list rules)])
|
|
(cons (rule-id a-rule) (sat:make-and)))))
|
|
|
|
(define leaves '())
|
|
|
|
(define (make-leaf)
|
|
(define a-leaf (sat:make-and))
|
|
(set! leaves (cons a-leaf leaves))
|
|
a-leaf)
|
|
|
|
(define (process-pattern a-pattern)
|
|
(syntax-case a-pattern (id lit token choice repeat maybe seq)
|
|
[(id val)
|
|
(free-id-table-ref toplevel-rule-table #'val)]
|
|
[(lit val)
|
|
(make-leaf)]
|
|
[(token val)
|
|
(make-leaf)]
|
|
[(choice . vals)
|
|
(let ([an-or-node (sat:make-or)])
|
|
(for* ([v (in-list (syntax->list #'vals))]
|
|
[a-child (in-value (process-pattern v))])
|
|
(sat:add-child! an-or-node a-child))
|
|
an-or-node)]
|
|
[(repeat min max val)
|
|
(syntax-case #'min ()
|
|
[0 (make-leaf)]
|
|
[_ (process-pattern #'val)])]
|
|
[(maybe val) (make-leaf)]
|
|
[(seq . vals)
|
|
(let ([an-and-node (sat:make-and)])
|
|
(for* ([v (in-list (syntax->list #'vals))]
|
|
[a-child (in-value (process-pattern v))])
|
|
(sat:add-child! an-and-node a-child))
|
|
an-and-node)]))
|
|
|
|
(for* ([a-rule (in-list rules)]
|
|
[rule-node (in-value (free-id-table-ref toplevel-rule-table (rule-id a-rule)))])
|
|
(sat:add-child! rule-node (process-pattern (rule-pattern a-rule))))
|
|
|
|
(for-each sat:visit! leaves)
|
|
|
|
(for* ([a-rule (in-list rules)]
|
|
[rule-node (in-value (free-id-table-ref toplevel-rule-table (rule-id a-rule)))]
|
|
#:unless (sat:node-yes? rule-node))
|
|
(raise-syntax-error #f
|
|
(format "Rule ~a has no finite derivation" (syntax-e (rule-id a-rule)))
|
|
(rule-id a-rule)))) |