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Support quantified repetition

Browse Source
remotes/jackfirth/master
Jack Firth 2 years ago
parent e5d7cab7cb
commit f36f33efde
1 changed files with 143 additions and 10 deletions
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153
base/grammar.rkt
Unescape Escape View File

@ -49,7 +49,8 @@
(-> flat-production-rule? (vectorof grammar-symbol? #:immutable #true))])))
(require racket/match
(require racket/list
racket/match
racket/sequence
racket/set
rebellion/collection/vector
@ -220,10 +221,12 @@
#:action splice-action
#:substitution
(sequence-append repetition-symbols (list subrule-symbol))))
(vector-builder-add new-rules empty-rule repetition-rule)
(vector-builder-add new-rules repetition-rule empty-rule)
subrule-symbol]))
(define processed (process-top-level-expression (production-rule-substitution rule)))
(define processed
(process-top-level-expression
(production-expression-simplify (production-rule-substitution rule))))
(define top-level-rule
(flat-production-rule
@ -234,6 +237,48 @@
(vector-reverse (build-vector new-rules)))
(define (production-expression-simplify expression)
(match expression
[(? terminal-symbol?) expression]
[(? nonterminal-symbol?) expression]
[(group-expression subexpressions)
(group-expression
(for/vector ([subexpr (in-vector subexpressions)])
(production-expression-simplify subexpr)))]
[(choice-expression choices)
(choice-expression
(for/vector ([subexpr (in-vector choices)])
(production-expression-simplify subexpr)))]
[(? repetition-expression?)
(match* ((repetition-expression-min-count expression)
(repetition-expression-max-count expression))
[(0 +inf.0)
(repetition-expression
(production-expression-simplify (repetition-expression-subexpression expression)))]
[(0 max)
(define subexpr
(production-expression-simplify (repetition-expression-subexpression expression)))
(for/fold ([expr (choice-expression (list (group-expression '()) subexpr))])
([_ (in-range (sub1 max))])
(choice-expression (list (group-expression '()) (group-expression (list subexpr expr)))))]
[(min +inf.0)
(define subexpr
(production-expression-simplify (repetition-expression-subexpression expression)))
(group-expression
(sequence-append (make-list min subexpr) (list (repetition-expression subexpr))))]
[(min max)
(define subexpr
(production-expression-simplify (repetition-expression-subexpression expression)))
(define tail-expr
(for/fold ([expr (choice-expression (list (group-expression '()) subexpr))])
([_ (in-range (- max min 1))])
(choice-expression (list (group-expression '()) (group-expression (list subexpr expr))))))
(group-expression (sequence-append (make-list min subexpr) (list tail-expr)))])]))
(define (vector-reverse vec)
(define size (vector-length vec))
(define copy (make-vector size))
@ -255,6 +300,10 @@
(define x (nonterminal-symbol 'x))
(define x.0 (nonterminal-symbol (virtual-symbol 'x 0)))
(define x.1 (nonterminal-symbol (virtual-symbol 'x 1)))
(define x.2 (nonterminal-symbol (virtual-symbol 'x 2)))
(define x.3 (nonterminal-symbol (virtual-symbol 'x 3)))
(define x.4 (nonterminal-symbol (virtual-symbol 'x 4)))
(define a (terminal-symbol 'a))
(define b (terminal-symbol 'b))
(define c (terminal-symbol 'c))
@ -305,8 +354,8 @@
;; ->
;;
;; x: a x.0
;; x.0: b x.0 (* splice *)
;; x.0: (* splice *)
;; x.0: b x.0 (* splice *)
(test-case "repeating"
(define rule
(production-rule
@ -317,12 +366,96 @@
(vector
(flat-production-rule
#:nonterminal x #:action (label-action 'x) #:substitution (list a x.0 c))
(flat-production-rule #:nonterminal x.0 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.0 #:action splice-action #:substitution (list b x.0))))
(check-equal? (production-rule-flatten rule) expected-rules))
;; x: a b{3..} c
;;
;; ->
;;
;; x: a x.0 c
;; x.0: b b b x.1 (* splice *)
;; x.1: (* splice *)
;; x.1: b x.1 (* splice *)
(test-case "repeating with min count"
(define rule
(production-rule
#:nonterminal x
#:action (label-action 'x)
#:substitution (group-expression (list a (repetition-expression b #:min-count 3) c))))
(define expected-rules
(vector
(flat-production-rule
#:nonterminal x.0
#:action splice-action
#:substitution (list b x.0))
#:nonterminal x #:action (label-action 'x) #:substitution (list a x.0 c))
(flat-production-rule
#:nonterminal x.0
#:action splice-action
#:substitution '())))
#:nonterminal x.0 #:action splice-action #:substitution (list b b b x.1))
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution (list b x.1))))
(check-equal? (production-rule-flatten rule) expected-rules))
;; x: a b{0..5} c
;;
;; ->
;;
;; x: a x.0 c
;; x.0: (* splice *)
;; x.0: b x.1 (* splice *)
;; x.1: (* splice *)
;; x.1: b x.2 (* splice *)
;; x.2: (* splice *)
;; x.2: b x.3 (* splice *)
;; x.3: (* splice *)
;; x.3: b x.4 (* splice *)
;; x.4: (* splice *)
;; x.4: b (* splice *)
(test-case "repeating with max count"
(define rule
(production-rule
#:nonterminal x
#:action (label-action 'x)
#:substitution (group-expression (list a (repetition-expression b #:max-count 5) c))))
(define expected-rules
(vector
(flat-production-rule
#:nonterminal x #:action (label-action 'x) #:substitution (list a x.0 c))
(flat-production-rule #:nonterminal x.0 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.0 #:action splice-action #:substitution (list b x.1))
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution (list b x.2))
(flat-production-rule #:nonterminal x.2 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.2 #:action splice-action #:substitution (list b x.3))
(flat-production-rule #:nonterminal x.3 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.3 #:action splice-action #:substitution (list b x.4))
(flat-production-rule #:nonterminal x.4 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.4 #:action splice-action #:substitution (list b))))
(check-equal? (production-rule-flatten rule) expected-rules))
;; x: a b{3..5} c
;;
;; ->
;;
;; x: a x.0 c
;; x.0: b b b x.1 (* splice *)
;; x.1: (* splice *)
;; x.1: b x.2 (* splice *)
;; x.2: (* splice *)
;; x.2: b (* splice *)
(test-case "repeating with min and max count"
(define rule
(production-rule
#:nonterminal x
#:action (label-action 'x)
#:substitution
(group-expression (list a (repetition-expression b #:min-count 3 #:max-count 5) c))))
(define expected-rules
(vector
(flat-production-rule
#:nonterminal x #:action (label-action 'x) #:substitution (list a x.0 c))
(flat-production-rule
#:nonterminal x.0 #:action splice-action #:substitution (list b b b x.1))
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.1 #:action splice-action #:substitution (list b x.2))
(flat-production-rule #:nonterminal x.2 #:action splice-action #:substitution '())
(flat-production-rule #:nonterminal x.2 #:action splice-action #:substitution (list b))))
(check-equal? (production-rule-flatten rule) expected-rules))))

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