racket/collects/redex/private/matcher.rkt
Robby Findler 7355c59fb1 added the ability to extract a derivation
from a judgment-form via build-derivation
(returns derivation structs)
2012-10-21 23:19:54 -05:00

2033 lines
80 KiB
Racket

#lang racket/base
;; optimization ideas:
;;
;; -- jay's idea
;;
;; -- when a list pattern has only a single repeat,
;; don't search for matches, just count
;;
;; -- need to figure out something to do with patterns
;; that have multiple ellipses in a sequence. Perhaps try
;; to look for the fixed parts and then see if the others
;; will fill in between them?
;;
;; -- when a match is unambiguous (and possibly only when
;; there are no names underneath an ellipsis),
;; pre-allocate the space to store the result (in a vector)
;;
;; -- change the way decomposition matching works to pass down
;; the pattern to match at the hole and match it there, so
;; that in situations like this: (in-hole E (+ n_1 n_2))
;; we don't return all of the bogus matches that show up
;; by treating the hole as 'any'.
;;
;; (this one turns out not to be so great because it
;; makes caching less effective)
;;
;; -- combine the left-hand sides of a reduction relation
;; so to avoid re-doing decompositions over and over
;; (maybe....)
;;
;; -- parallelism? but what about the hash-table cache?
;;
#|
Note: the patterns described in the documentation are
slightly different than the patterns processed here.
See match-a-pattern.rkt for more details
|#
(require racket/list
racket/match
racket/contract
racket/promise
racket/performance-hint
(for-syntax racket/base)
"underscore-allowed.rkt"
"match-a-pattern.rkt")
(define-struct compiled-pattern (cp binds-names? skip-dup-check?) #:transparent)
(define caching-enabled? (make-parameter #t))
;; lang = (listof nt)
;; nt = (make-nt sym (listof rhs))
;; rhs = (make-rhs single-pattern)
;; single-pattern = sexp
(define-struct nt (name rhs) #:transparent)
(define-struct rhs (pattern) #:transparent)
;; var = (make-var sym sexp)
;; patterns are sexps with `var's embedded
;; in them. It means to match the
;; embedded sexp and return that binding
;; bindings = (make-bindings (listof rib))
;; rib = (make-bind sym sexp)
;; if a rib has a pair, the first element of the pair should be treated as a prefix on the identifier
;; NOTE: the bindings may contain mismatch-ribs temporarily, but they are all removed
;; by merge-multiples/remove, a helper function called from match-pattern
(define-values (make-bindings bindings-table bindings? empty-bindings)
(let ()
(define-struct bindings (table) #:transparent) ;; for testing, add inspector
(define empty-bindings (make-bindings '()))
(values (lambda (table) (if (null? table) empty-bindings (make-bindings table)))
bindings-table
bindings?
empty-bindings)))
(define-struct bind (name exp) #:transparent)
(define-struct mismatch-bind (name exp) #:transparent)
;; repeat = (make-repeat compiled-pattern (listof rib) (or/c #f symbol?) (or/c #f symbol?))
(define-struct repeat (pat empty-bindings name mismatch) #:transparent)
;; compiled-pattern : exp hole-info -> (union #f (listof mtch))
;; mtch = (make-mtch bindings sexp[context] (union none sexp[hole]))
;; hole-info = boolean
;; #f means we're not in a `in-hole' context
;; #t means we're looking for a hole
(define-values (mtch-bindings mtch-context mtch-hole make-mtch mtch?)
(let ()
(define-struct mtch (bindings context hole) #:inspector (make-inspector))
(values mtch-bindings
mtch-context
mtch-hole
(lambda (a b c)
(unless (bindings? a)
(error 'make-mtch "expected bindings for first agument, got ~e" a))
(make-mtch a b c))
mtch?)))
(define none
(let ()
(define-struct none ())
(make-none)))
(define (none? x) (eq? x none))
;; compiled-lang : (make-compiled-lang (listof nt)
;; hash[sym -o> compiled-pattern]
;; hash[sym -o> compiled-pattern]
;; hash[sym -o> compiled-pattern]
;; hash[sym -o> boolean])
;; hash[sexp[pattern] -o> (cons compiled-pattern boolean)]
;; hash[sexp[pattern] -o> (cons compiled-pattern boolean)]
;; pict-builder
;; (listof symbol)
;; (listof (listof symbol))) -- keeps track of `primary' non-terminals
;; hash[sym -o> pattern]
(define-struct compiled-lang (lang delayed-cclang ht list-ht raw-across-ht raw-across-list-ht
has-hole-or-hide-hole-ht cache bind-names-cache pict-builder
literals nt-map collapsible-nts))
(define (compiled-lang-cclang x) (force (compiled-lang-delayed-cclang x)))
(define (compiled-lang-across-ht x)
(compiled-lang-cclang x) ;; ensure this is computed
(compiled-lang-raw-across-ht x))
(define (compiled-lang-across-list-ht x)
(compiled-lang-cclang x) ;; ensure this is computed
(compiled-lang-raw-across-list-ht x))
;; lookup-binding : bindings (union sym (cons sym sym)) [(-> any)] -> any
(begin-encourage-inline
(define (lookup-binding bindings
sym
[fail (lambda ()
(error 'lookup-binding "didn't find ~e in ~e" sym bindings))])
(let loop ([ribs (bindings-table bindings)])
(cond
[(null? ribs) (fail)]
[else
(let ([rib (car ribs)])
(if (and (bind? rib) (eq? (bind-name rib) sym))
(bind-exp rib)
(loop (cdr ribs))))]))))
;; compile-language : language-pict-info[see pict.rkt] (listof nt) (listof (listof sym)) -> compiled-lang
(define (compile-language pict-info lang nt-map)
(let* ([clang-ht (make-hasheq)]
[clang-list-ht (make-hasheq)]
[across-ht (make-hasheq)]
[across-list-ht (make-hasheq)]
[has-hole-or-hide-hole-ht (build-has-hole-or-hide-hole-ht lang)]
[cache (make-hash)]
[bind-names-cache (make-hash)]
[literals (extract-literals lang)]
[collapsible-nts (extract-collapsible-nts lang)]
[clang (make-compiled-lang lang #f clang-ht clang-list-ht
across-ht across-list-ht
has-hole-or-hide-hole-ht
cache bind-names-cache
pict-info
literals
nt-map
collapsible-nts)]
[non-list-nt-table (build-non-list-nt-label lang)]
[list-nt-table (build-list-nt-label lang)]
[do-compilation
(lambda (ht list-ht lang)
(for ([nt (in-list lang)])
(for ([rhs (in-list (nt-rhs nt))])
(define-values (compiled-pattern-proc has-hole? has-hide-hole? names)
(compile-pattern/cross? clang (rhs-pattern rhs) #f))
(define (add-to-ht ht)
(define nv (cons (build-compiled-pattern compiled-pattern-proc names)
(hash-ref ht (nt-name nt))))
(hash-set! ht (nt-name nt) nv))
(define may-be-non-list? (may-be-non-list-pattern? (rhs-pattern rhs) non-list-nt-table))
(define may-be-list? (may-be-list-pattern? (rhs-pattern rhs) list-nt-table))
(when may-be-non-list? (add-to-ht ht))
(when may-be-list? (add-to-ht list-ht))
(unless (or may-be-non-list? may-be-list?)
(error 'compile-language
"internal error: unable to determine whether pattern matches lists, non-lists, or both: ~s"
(rhs-pattern rhs))))))]
[init-ht
(lambda (ht)
(for-each (lambda (nt) (hash-set! ht (nt-name nt) null))
lang))])
(init-ht clang-ht)
(init-ht clang-list-ht)
(hash-for-each
clang-ht
(lambda (nt rhs)
(when (has-underscore? nt)
(error 'compile-language "cannot use underscore in nonterminal name, ~s" nt))))
(define compatible-context-language
(delay
(let ([compatible-context-language
(build-compatible-context-language clang-ht lang)])
(for-each (lambda (nt)
(hash-set! across-ht (nt-name nt) null)
(hash-set! across-list-ht (nt-name nt) null))
compatible-context-language)
(do-compilation across-ht across-list-ht compatible-context-language)
compatible-context-language)))
(do-compilation clang-ht clang-list-ht lang)
(struct-copy compiled-lang clang [delayed-cclang compatible-context-language])))
;; extract-collapsible-nts : (listof nt) -> (listof any)
(define (extract-collapsible-nts nts)
(define nt-hash (for/hasheq ([nt nts])
(values (nt-name nt) (nt-rhs nt))))
(for/fold ([c-nts (hasheq)])
([nt (in-hash-keys nt-hash)])
(let loop ([rhss (hash-ref nt-hash nt)])
(if (= (length rhss) 1)
(match (rhs-pattern (car rhss))
[`(nt ,next)
(loop (hash-ref nt-hash next))]
[else
(hash-set c-nts nt (rhs-pattern (car rhss)))])
c-nts))))
;; extract-literals : (listof nt) -> (listof symbol)
(define (extract-literals nts)
(let ([literals-ht (make-hasheq)]
[nt-names (map nt-name nts)])
(for-each (λ (nt)
(for-each (λ (rhs) (extract-literals/pat nt-names (rhs-pattern rhs) literals-ht))
(nt-rhs nt)))
nts)
(hash-map literals-ht (λ (x y) x))))
;; extract-literals/pat : (listof sym) pattern ht -> void
;; inserts the literals mentioned in pat into ht
(define (extract-literals/pat nts pat ht)
(let loop ([pat pat])
(match-a-pattern pat
[`any (void)]
[`number (void)]
[`string (void)]
[`natural (void)]
[`integer (void)]
[`real (void)]
[`variable (void)]
[`(variable-except ,s ...) (void)]
[`(variable-prefix ,s) (void)]
[`variable-not-otherwise-mentioned (void)]
[`hole (void)]
[`(nt ,id) (void)]
[`(name ,name ,pat) (loop pat)]
[`(mismatch-name ,name ,pat) (loop pat)]
[`(in-hole ,p1 ,p2)
(loop p1)
(loop p2)]
[`(hide-hole ,p) (loop p)]
[`(side-condition ,p ,g ,e)
(loop p)]
[`(cross ,s) (void)]
[`(list ,sub-pats ...)
(for ([sub-pat (in-list sub-pats)])
(match sub-pat
[`(repeat ,pat ,name ,mismatch)
(loop pat)]
[else
(loop sub-pat)]))]
[(? (compose not pair?))
(when (symbol? pat)
(unless (regexp-match #rx"_" (symbol->string pat))
(unless (regexp-match #rx"^\\.\\.\\." (symbol->string pat))
(unless (memq pat nts)
(hash-set! ht pat #t)))))])))
;; prefix-nts : string pat -> pat
(define (prefix-nts prefix pat)
(let loop ([pat pat])
(match-a-pattern pat
[`any pat]
[`number pat]
[`string pat]
[`natural pat]
[`integer pat]
[`real pat]
[`variable pat]
[`(variable-except ,s ...) pat]
[`(variable-prefix ,s) pat]
[`variable-not-otherwise-mentioned pat]
[`hole pat]
[`(nt ,id) `(nt ,(string->symbol (string-append prefix (symbol->string id))))]
[`(name ,name ,pat) `(name , name ,(loop pat))]
[`(mismatch-name ,name ,pat) `(mismatch-name ,name ,(loop pat))]
[`(in-hole ,p1 ,p2) `(in-hole ,(loop p1) ,(loop p2))]
[`(hide-hole ,p) `(hide-hole ,(loop p))]
[`(side-condition ,p ,g ,e) `(side-condition ,(loop p) ,g ,e)]
[`(cross ,s) pat]
[`(list ,sub-pats ...)
`(list ,@(for/list ([sub-pat (in-list sub-pats)])
(match sub-pat
[`(repeat ,pat ,name ,mismatch)
`(repeat ,(loop pat) ,name ,mismatch)]
[else
(loop sub-pat)])))]
[(? (compose not pair?))
pat])))
; build-has-hole-or-hide-hole-ht : (listof nt) -> hash[symbol -o> boolean]
; produces a map of nonterminal -> whether that nonterminal could produce a hole
(define (build-has-hole-or-hide-hole-ht lang)
(build-nt-property
lang
(lambda (pattern ht)
(let loop ([pattern pattern])
(match-a-pattern pattern
[`any #f]
[`number #f]
[`string #f]
[`natural #f]
[`integer #f]
[`real #f]
[`variable #f]
[`(variable-except ,vars ...) #f]
[`(variable-prefix ,var) #f]
[`variable-not-otherwise-mentioned #f]
[`hole #t]
[`(nt ,id) (hash-ref ht id)]
[`(name ,name ,pat) (loop pat)]
[`(mismatch-name ,name ,pat) (loop pat)]
[`(in-hole ,context ,contractum) (loop contractum)]
[`(hide-hole ,arg) #t]
[`(side-condition ,pat ,condition ,expr) (loop pat)]
[`(cross ,nt) #f]
[`(list ,pats ...)
(for/or ([pat (in-list pats)])
(match pat
[`(repeat ,pat ,name ,mismatch?) (loop pat)]
[_ (loop pat)]))]
[(? (compose not pair?)) #f])))
#f
(λ (x y) (or x y))))
;; build-nt-property : lang
;; (pattern hash[nt -o> ans] -> ans)
;; init-ans
;; (ans ans ans)
;; -> hash[nt -o> ans]
;; builds a property table using a fixed point computation,
;; using base-answer and lub as the lattice
(define (build-nt-property lang test-rhs base-answer lub)
(define ht (make-hash))
(for ([nt (in-list lang)])
(hash-set! ht (nt-name nt) base-answer))
(let loop ()
(define something-changed? #f)
(for ([nt (in-list lang)])
(define next-val
(for/fold ([acc base-answer])
([rhs (in-list (nt-rhs nt))])
(lub acc (test-rhs (rhs-pattern rhs) ht))))
(unless (equal? next-val (hash-ref ht (nt-name nt)))
(hash-set! ht (nt-name nt) next-val)
(set! something-changed? #t)))
(when something-changed? (loop)))
ht)
;; build-compatible-context-language : lang -> lang
(define (build-compatible-context-language clang-ht lang)
(remove-empty-compatible-contexts
(apply
append
(map
(lambda (nt1)
(map
(lambda (nt2)
(let ([compat-nt (build-compatible-contexts/nt clang-ht (nt-name nt1) nt2)])
(if (eq? (nt-name nt1) (nt-name nt2))
(make-nt (nt-name compat-nt)
(cons
(make-rhs 'hole)
(nt-rhs compat-nt)))
compat-nt)))
lang))
lang))))
;; remove-empty-compatible-contexts : lang -> lang
;; Removes the empty compatible context non-terminals and the
;; rhss that reference them.
(define (remove-empty-compatible-contexts lang)
(define (has-cross? pattern crosses)
(match pattern
[`(cross ,(? symbol? nt)) (memq nt crosses)]
[(list-rest p '... rest) (has-cross? rest crosses)]
[(cons first rest) (or (has-cross? first crosses)
(has-cross? rest crosses))]
[_ #f]))
(define (delete-empty nts)
(for/fold ([deleted null] [kept null]) ([nt nts])
(if (null? (nt-rhs nt))
(values (cons nt deleted) kept)
(values deleted (cons nt kept)))))
(define (delete-references deleted-names remaining-nts)
(map (λ (nt)
(make-nt (nt-name nt)
(filter (λ (rhs) (not (has-cross? (rhs-pattern rhs) deleted-names)))
(nt-rhs nt))))
remaining-nts))
(let loop ([nts lang])
(let-values ([(deleted kept) (delete-empty nts)])
(if (null? deleted)
kept
(loop (delete-references (map nt-name deleted) kept))))))
;; build-compatible-contexts : clang-ht prefix nt -> nt
;; constructs the compatible closure evaluation context from nt.
(define (build-compatible-contexts/nt clang-ht prefix nt)
(make-nt
(symbol-append prefix '- (nt-name nt))
(apply append
(map
(lambda (rhs)
(let-values ([(maker count) (build-compatible-context-maker clang-ht
(rhs-pattern rhs)
prefix)])
(let loop ([i count])
(cond
[(zero? i) null]
[else (let ([nts (build-across-nts (nt-name nt) count (- i 1))])
(cons (make-rhs (maker (box nts)))
(loop (- i 1))))]))))
(nt-rhs nt)))))
(define (symbol-append . args)
(string->symbol (apply string-append (map symbol->string args))))
;; build-across-nts : symbol number number -> (listof pattern)
(define (build-across-nts nt count i)
(let loop ([j count])
(cond
[(zero? j) null]
[else
(cons (= i (- j 1))
(loop (- j 1)))])))
;; build-compatible-context-maker : symbol pattern -> (values ((box (listof pattern)) -> pattern) number)
;; when the result function is applied, it takes each element
;; of the of the boxed list and plugs them into the places where
;; the nt corresponding from this rhs appeared in the original pattern.
;; The number result is the number of times that the nt appeared in the pattern.
(define (build-compatible-context-maker clang-ht pattern prefix)
(let ([count 0])
(define maker
(let loop ([pattern pattern])
(define (untouched-pattern _)
(values pattern #f))
(match-a-pattern pattern
[`any untouched-pattern]
[`number untouched-pattern]
[`string untouched-pattern]
[`natural untouched-pattern]
[`integer untouched-pattern]
[`real untouched-pattern]
[`variable untouched-pattern]
[`(variable-except ,vars ...) untouched-pattern]
[`(variable-prefix ,var) untouched-pattern]
[`variable-not-otherwise-mentioned untouched-pattern]
[`hole untouched-pattern]
[`(nt ,name)
(cond
[(hash-ref clang-ht name #f)
(set! count (+ count 1))
(lambda (l)
(let ([fst (car (unbox l))])
(set-box! l (cdr (unbox l)))
(if fst
(values `(cross ,(symbol-append prefix '- name)) #t)
(values pattern #f))))]
[else untouched-pattern])]
[`(name ,name ,pat)
(let ([patf (loop pat)])
(lambda (l)
(let-values ([(p h?) (patf l)])
(values `(name ,name ,p) h?))))]
[`(mismatch-name ,name ,pat)
(let ([patf (loop pat)])
(lambda (l)
(let-values ([(p h?) (patf l)])
(values `(mismatch-name ,name ,p) h?))))]
[`(in-hole ,context ,contractum)
(let ([match-context (loop context)]
[match-contractum (loop contractum)])
(lambda (l)
(let-values ([(ctxt _) (match-context l)]
[(ctct h?) (match-contractum l)])
(values `(in-hole ,ctxt ,ctct) h?))))]
[`(hide-hole ,p)
(let ([m (loop p)])
(lambda (l)
(let-values ([(p h?) (m l)])
(if h?
(values p #t)
(values `(hide-hole ,p) #f)))))]
[`(side-condition ,pat ,condition ,expr)
(let ([patf (loop pat)])
(lambda (l)
(let-values ([(p h?) (patf l)])
(values `(side-condition ,p ,condition ,expr) h?))))]
[`(cross ,arg) untouched-pattern]
[`(list ,pats ...)
(define pre-cross
(for/list ([sub-pat (in-list pats)])
(match sub-pat
[`(repeat ,pat ,name ,mismatch)
(list (loop pat) sub-pat)]
[else
(list (loop sub-pat) #f)])))
(λ (l)
(define any-cross? #f)
(define post-cross
(map (match-lambda
[(list f r?)
(let-values ([(p h?) (f l)])
(set! any-cross? (or any-cross? h?))
(list p h? r?))])
pre-cross))
(define (hide p)
(if any-cross?
(match p
[`(repeat ,p ,name ,mismatch?)
`(repeat (hide-hole ,p) ,name ,mismatch?)]
[_
`(hide-hole ,p)])
p))
(values
`(list ,@(foldr (λ (post tail)
(match post
[(list p* #t (and (not #f) p))
`(,(hide p) ,p* ,(hide p) . ,tail)]
[(list p #f (not #f))
`((repeat ,(hide p) #f #f) . ,tail)]
[(list p* #t #f)
`(,p* . ,tail)]
[(list p #f #f)
`(,(hide p) . ,tail)]))
'()
post-cross))
any-cross?))]
[(? (compose not pair?)) untouched-pattern])))
(values (λ (l) (let-values ([(p _) (maker l)]) p))
count)))
;; build-list-nt-label : lang -> hash[symbol -o> boolean]
(define (build-list-nt-label lang)
(build-nt-property lang
may-be-list-pattern?
#f
(λ (x y) (or x y))))
(define (may-be-list-pattern? pattern nt-table)
(let loop ([pattern pattern])
(match-a-pattern pattern
[`any #t]
[`number #f]
[`string #f]
[`natural #f]
[`integer #f]
[`real #f]
[`variable #f]
[`(variable-except ,vars ...) #f]
[`(variable-prefix ,var) #f]
[`variable-not-otherwise-mentioned #f]
[`hole #t]
[`(nt ,id) (hash-ref nt-table id)]
[`(name ,id ,pat) (loop pat)]
[`(mismatch-name ,id ,pat) (loop pat)]
[`(in-hole ,context ,contractum)
;; pessimistic, assumes that context can be 'hole' directly
(or (loop context) (loop contractum))]
[`(hide-hole ,p) (loop p)]
[`(side-condition ,pat ,condition ,expr) (loop pat)]
[`(cross ,nt) #t]
[`(list ,pats ...) #t]
[(? (compose not pair?)) #f])))
;; build-non-list-nt-label : lang -> hash[symbol -o> boolean]
(define (build-non-list-nt-label lang)
(build-nt-property lang
may-be-non-list-pattern?
#f
(λ (x y) (or x y))))
(define (may-be-non-list-pattern? pattern ht)
(let loop ([pattern pattern])
(match-a-pattern pattern
[`any #t]
[`number #t]
[`string #t]
[`natural #t]
[`integer #t]
[`real #t]
[`variable #t]
[`(variable-except ,vars ...) #t]
[`(variable-prefix ,prefix) #t]
[`variable-not-otherwise-mentioned #t]
[`hole #t]
[`(nt ,nt) (hash-ref ht nt)]
[`(name ,name ,pat) (loop pat)]
[`(mismatch-name ,name ,pat) (loop pat)]
[`(in-hole ,context ,contractum)
;; pessimistic, assumes that context can be 'hole' directly
(or (loop context) (loop contractum))]
[`(hide-hole ,p) (loop p)]
[`(side-condition ,pat ,condition ,expr) (loop pat)]
[`(cross ,nt) #t]
[`(list ,pats ...) #f]
[(? (compose not pair?)) #t])))
;; match-pattern? : compiled-pattern exp -> boolean
(define (match-pattern? compiled-pattern exp)
(let ([results ((compiled-pattern-cp compiled-pattern) exp #f)])
(and results #t)))
;; match-pattern : compiled-pattern exp -> (union #f (listof bindings))
(define (match-pattern compiled-pattern exp)
(let ([results ((compiled-pattern-cp compiled-pattern) exp #f)])
(if (compiled-pattern-skip-dup-check? compiled-pattern)
results
(and results
(let ([filtered (filter-multiples results)])
(and (not (null? filtered))
filtered))))))
;; filter-multiples : (listof mtch) -> (listof mtch)
(define (filter-multiples matches)
;(printf "matches ~s\n" matches)
(let loop ([matches matches]
[acc null])
(cond
[(null? matches)
;; this reverse here is to get things back
;; in the same order that they'd be in if the
;; skip-dup-check? bolean had been true
(reverse acc)]
[else
(let ([merged (merge-multiples/remove (car matches))])
(if merged
(loop (cdr matches) (cons merged acc))
(loop (cdr matches) acc)))])))
;; merge-multiples/remove : bindings -> (union #f bindings)
;; returns #f if all duplicate bindings don't bind the same thing
;; returns a new bindings
(define (merge-multiples/remove match)
(let/ec fail
(let (
;; match-ht : sym -o> sexp
[match-ht (make-hash)]
;; mismatch-ht : sym -o> hash[sexp -o> #t]
[mismatch-ht (make-hash)]
[ribs (bindings-table (mtch-bindings match))])
(for-each
(lambda (rib)
(cond
[(bind? rib)
(let ([name (bind-name rib)]
[exp (bind-exp rib)])
(let ([previous-exp (hash-ref match-ht name uniq)])
(cond
[(eq? previous-exp uniq)
(hash-set! match-ht name exp)]
[else
(unless (equal? exp previous-exp)
(fail #f))])))]
[(mismatch-bind? rib)
(let* ([name (mismatch-bind-name rib)]
[exp (mismatch-bind-exp rib)]
[priors (hash-ref mismatch-ht name uniq)])
(when (eq? priors uniq)
(let ([table (make-hash)])
(hash-set! mismatch-ht name table)
(set! priors table)))
(when (hash-ref priors exp #f)
(fail #f))
(hash-set! priors exp #t))]))
ribs)
(make-mtch
(make-bindings (hash-map match-ht make-bind))
(mtch-context match)
(mtch-hole match)))))
;; compile-pattern : compiled-lang pattern boolean -> compiled-pattern
(define (compile-pattern clang pattern bind-names?)
(let-values ([(pattern has-hole? has-hide-hole? names) (compile-pattern/cross? clang pattern bind-names?)])
(build-compiled-pattern (if (or has-hole? has-hide-hole? (not (null? names)))
pattern
(convert-matcher pattern))
names)))
(define (build-compiled-pattern proc names)
(make-compiled-pattern proc
(null? names)
;; none of the names are duplicated
(and (equal? names (remove-duplicates names))
;; no mismatch names
(not (for/or ([name (in-list names)])
(pair? name))))))
;; compile-pattern/cross? : compiled-lang pattern boolean -> (values compiled-pattern boolean)
(define (compile-pattern/cross? clang pattern bind-names?)
(define clang-ht (compiled-lang-ht clang))
(define clang-list-ht (compiled-lang-list-ht clang))
(define has-hole-or-hide-hole-ht (compiled-lang-has-hole-or-hide-hole-ht clang))
(define (compile-pattern/default-cache pattern)
(compile-pattern/cache pattern
(if bind-names?
(compiled-lang-bind-names-cache clang)
(compiled-lang-cache clang))))
(define in-name-parameter (make-parameter #f))
(define (compile-pattern/cache pattern compiled-pattern-cache)
(let ([compiled-cache (hash-ref compiled-pattern-cache pattern uniq)])
(cond
[(eq? compiled-cache uniq)
(define-values (compiled-pattern has-hole? has-hide-hole? names) (true-compile-pattern pattern))
(unless (equal? (if (or has-hole? has-hide-hole? (not (null? names)))
2
1)
(procedure-arity compiled-pattern))
(error 'compile-pattern "got procedure with wrong arity; pattern ~s ~s ~s ~s ~s\n"
pattern compiled-pattern has-hole? has-hide-hole? names))
(define val (list (match pattern
[`(nt ,p)
(memoize compiled-pattern has-hole?)]
[_ compiled-pattern])
has-hole?
has-hide-hole?
names))
(hash-set! compiled-pattern-cache pattern val)
(apply values val)]
[else
(apply values compiled-cache)])))
;; invariant : if both result booleans are #f (ie, no-hole and no names), then
;; the result (matching) function returns a boolean and has arity 1.
;; otherwise it is a compiled-pattern function (ie returning a list
;; of assoc tables)
(define (true-compile-pattern pattern)
(match-a-pattern pattern
[`any (simple-match (λ (x) #t))]
[`number (simple-match number?)]
[`string (simple-match string?)]
[`natural (simple-match exact-nonnegative-integer?)]
[`integer (simple-match exact-integer?)]
[`real (simple-match real?)]
[`variable (simple-match symbol?)]
[`(variable-except ,vars ...)
(simple-match
(λ (exp)
(and (symbol? exp)
(not (memq exp vars)))))]
[`(variable-prefix ,var)
(define prefix-str (symbol->string var))
(define prefix-len (string-length prefix-str))
(simple-match
(λ (exp)
(and (symbol? exp)
(let ([str (symbol->string exp)])
(and ((string-length str) . >= . prefix-len)
(string=? (substring str 0 prefix-len) prefix-str))))))]
[`variable-not-otherwise-mentioned
(let ([literals (compiled-lang-literals clang)])
(simple-match
(λ (exp)
(and (symbol? exp)
(not (memq exp literals))))))]
[`hole
(values match-hole #t #f '())]
[`(nt ,nt)
(define in-name? (in-name-parameter))
(define has-hole? (hash-ref has-hole-or-hide-hole-ht nt))
(values
(if has-hole?
(λ (exp hole-info)
(match-nt (hash-ref clang-list-ht nt)
(hash-ref clang-ht nt)
nt exp hole-info))
(λ (exp)
(match-nt/boolean
(hash-ref clang-list-ht nt)
(hash-ref clang-ht nt)
nt exp)))
has-hole?
#f
'())]
[`(name ,name ,pat)
(define-values (match-pat has-hole? has-hide-hole? names)
(parameterize ([in-name-parameter #t])
(compile-pattern/default-cache pat)))
(values (match-named-pat name (if (or has-hide-hole? has-hole? (not (null? names)))
match-pat
(convert-matcher match-pat))
#f)
has-hole?
has-hide-hole?
(cons name names))]
[`(mismatch-name ,name ,pat)
(define-values (match-pat has-hole? has-hide-hole? names) (compile-pattern/default-cache pat))
(values (match-named-pat name (if (or has-hide-hole? has-hole? (not (null? names)))
match-pat
(convert-matcher match-pat))
#t)
has-hole?
has-hide-hole?
(cons `(mismatch-name name) names))]
[`(in-hole ,context ,contractum)
(define-values (match-context ctxt-has-hole? ctxt-has-hide-hole? ctxt-names)
(compile-pattern/default-cache context))
(define-values (match-contractum contractum-has-hole? contractum-has-hide-hole? contractum-names)
(compile-pattern/default-cache contractum))
(unless ctxt-has-hole?
(error 'compile-pattern
"found an in-hole pattern whose context position has no hole ~s"
pattern))
(values
(if (or ctxt-has-hide-hole?
contractum-has-hole?
contractum-has-hide-hole?
(not (null? ctxt-names))
(not (null? contractum-names)))
(match-in-hole context
contractum
exp
match-context
(if (or contractum-has-hole? contractum-has-hide-hole? (not (null? contractum-names)))
match-contractum
(convert-matcher match-contractum)))
(match-in-hole/contractum-boolean context
contractum
exp
match-context
match-contractum))
contractum-has-hole?
(or ctxt-has-hide-hole? contractum-has-hide-hole?)
(append ctxt-names contractum-names))]
[`(hide-hole ,p)
(define-values (match-pat has-hole? has-hide-hole? names) (compile-pattern/default-cache p))
(values
(cond
[(or has-hole? has-hide-hole? (not (null? names)))
(lambda (exp hole-info)
(let ([matches (match-pat exp #f)])
(and matches
(map (λ (match) (make-mtch (mtch-bindings match)
(hole->not-hole (mtch-context match))
none))
matches))))]
[else
(lambda (exp hole-info)
(let ([matches (match-pat exp)])
(and matches
(list (make-mtch empty-bindings
(hole->not-hole exp)
none)))))])
#f
#t
names)]
[`(side-condition ,pat ,condition ,expr)
(define-values (match-pat has-hole? has-hide-hole? names) (compile-pattern/default-cache pat))
(values
(if (or has-hole? has-hide-hole? (not (null? names)))
(λ (exp hole-info)
(let ([matches (match-pat exp hole-info)])
(and matches
(let ([filtered (filter (λ (m) (condition (mtch-bindings m)))
(filter-multiples matches))])
(if (null? filtered)
#f
filtered)))))
(λ (exp)
(and (match-pat exp)
(condition empty-bindings))))
has-hole?
has-hide-hole?
names)]
[`(cross ,(? symbol? id))
(define across-ht (compiled-lang-across-ht clang))
(define across-list-ht (compiled-lang-across-list-ht clang))
(cond
[(hash-maps? across-ht id)
(values
(λ (exp hole-info)
(match-nt (hash-ref across-list-ht id)
(hash-ref across-ht id)
id exp hole-info))
#t
#f
'())]
[else
(error 'compile-pattern "unknown cross reference ~a" id)])]
[`(list ,pats ...)
(define-values (rewritten has-hole?s has-hide-hole?s namess) (rewrite-ellipses pats compile-pattern/default-cache))
(define any-has-hole? (ormap values has-hole?s))
(define any-has-hide-hole? (ormap values has-hide-hole?s))
(define repeats (length (filter repeat? rewritten)))
(define non-repeats (length (filter (λ (x) (not (repeat? x))) rewritten)))
(define names (apply append namess))
(define rewritten/coerced
(for/list ([pat (in-list rewritten)]
[has-hole? (in-list has-hole?s)]
[has-hide-hole? (in-list has-hide-hole?s)]
[names (in-list namess)])
(cond
[(repeat? pat)
;; have to use procedure arity test here in case the
;; name on this pattern is in the repeat (in which case
;; the has-hide-hole? boolean will be true, but pat
;; may not need converting)
(if (equal? (procedure-arity (repeat-pat pat))
2)
pat
(struct-copy repeat pat [pat (convert-matcher (repeat-pat pat))]))]
[else
(if (or has-hole? has-hide-hole? (not (null? names)))
pat
(convert-matcher pat))])))
(values
(cond
[(not (or any-has-hole? any-has-hide-hole? (not (null? names))))
(λ (exp)
(cond
[(list? exp) (match-list/boolean rewritten exp)]
[else #f]))]
[(= 0 repeats)
(λ (exp hole-info)
(cond
[(list? exp)
;; shortcircuit: if the list isn't the right length, give up immediately.
(if (= (length exp) non-repeats)
(match-list/no-repeats rewritten/coerced exp hole-info)
#f)]
[else #f]))]
[else
(λ (exp hole-info)
(cond
[(list? exp)
;; shortcircuit: if the list doesn't have the right number of
;; fixed parts, give up immediately
(if (>= (length exp) non-repeats)
(match-list rewritten/coerced exp hole-info)
#f)]
[else #f]))])
any-has-hole?
any-has-hide-hole?
names)]
[(? (compose not pair?))
(cond
[(compiled-pattern? pattern) ;; can this really happen anymore?!
(values (compiled-pattern-cp pattern)
;; return #ts here as a failsafe; no way to check better.
#t
#t)]
[(eq? pattern '....)
;; this should probably be checked at compile time, not here
(error 'compile-language "the pattern .... can only be used in extend-language")]
[else
(simple-match
(λ (exp)
(equal? pattern exp)))])]))
;; simple-match : (any -> bool) -> (values <compiled-pattern> boolean boolean)
;; does a match based on a predicate
(define (simple-match pred)
(values (lambda (exp) (pred exp))
#f
#f
'()))
(compile-pattern/default-cache pattern))
;; convert-matcher : (any -> boolean) -> <compiled-pattern>
(define (convert-matcher boolean-based-matcher)
(unless (equal? (procedure-arity boolean-based-matcher) 1)
(error 'convert-matcher
"not a unary proc: ~s"
boolean-based-matcher))
(define (match-boolean-to-record-converter exp hole-info)
(and (boolean-based-matcher exp)
(list (make-mtch empty-bindings
(build-flat-context exp)
none))))
match-boolean-to-record-converter)
;; match-named-pat : symbol <compiled-pattern> -> <compiled-pattern>
(define (match-named-pat name match-pat mismatch-bind?)
(λ (exp hole-info)
(let ([matches (match-pat exp hole-info)])
(and matches
(map (lambda (match)
(make-mtch
(make-bindings (cons (if mismatch-bind?
(make-mismatch-bind name (mtch-context match))
(make-bind name (mtch-context match)))
(bindings-table (mtch-bindings match))))
(mtch-context match)
(mtch-hole match)))
matches)))))
;; has-underscore? : symbol -> boolean
(define (has-underscore? sym)
(memq #\_ (string->list (symbol->string sym))))
(define (memoize f needs-all-args?)
(case (procedure-arity f)
[(1) (memoize/1 f nohole)]
[(2) (memoize/2 f w/hole)]
[else (error 'memoize "unknown arity for ~s" f)]))
(define cache-size 63)
(define (set-cache-size! cs) (set! cache-size cs))
;; original version, but without closure allocation in hash lookup
(define-syntax (mk-memoize-key stx)
(syntax-case stx ()
[(_ arity)
(with-syntax ([(args ...) (generate-temporaries (build-list (syntax-e #'arity) (λ (x) 'x)))])
(with-syntax ([key-exp (if (= 1 (syntax-e #'arity))
(car (syntax->list #'(args ...)))
#'(list args ...))])
#'(λ (f statsbox)
(let ([ht (make-hash)]
[entries 0])
(lambda (args ...)
(cond
[(not (caching-enabled?)) (f args ...)]
[else
(let* ([key key-exp])
;(record-cache-test! statsbox)
(unless (< entries cache-size)
(set! entries 0)
(set! ht (make-hash)))
(let ([ans (hash-ref ht key uniq)])
(cond
[(eq? ans uniq)
;(record-cache-miss! statsbox)
(set! entries (+ entries 1))
(let ([res (f args ...)])
(hash-set! ht key res)
res)]
[else ans])))]))))))]))
;(define memoize/1 (mk-memoize-key 1))
;(define memoize/2 (mk-memoize-key 2))
(define-syntax (mk-memoize-vec stx)
(syntax-case stx ()
[(_ arity)
(with-syntax ([(args ...) (generate-temporaries (build-list (syntax-e #'arity) (λ (x) 'x)))])
(with-syntax ([key-exp (if (= 1 (syntax-e #'arity))
(car (syntax->list #'(args ...)))
#'(list args ...))])
#'(λ (f statsbox)
(let* ([uniq (gensym)]
[this-cache-size cache-size]
[ans-vec (make-vector this-cache-size uniq)]
[key-vec (make-vector this-cache-size uniq)])
(lambda (args ...)
(cond
[(not (caching-enabled?)) (f args ...)]
[else
;(record-cache-test! statsbox)
;(when (zero? (modulo (cache-stats-hits statsbox) 1000))
; (record-cache-size! statsbox (cons ans-vec key-vec)))
(let* ([key key-exp]
[index (modulo (equal-hash-code key) this-cache-size)])
(cond
[(equal? (vector-ref key-vec index) key)
(vector-ref ans-vec index)]
[else
;(record-cache-miss! statsbox)
(unless (eq? uniq (vector-ref key-vec index)) (record-cache-clobber! statsbox))
(let ([ans (f args ...)])
(vector-set! key-vec index key)
(vector-set! ans-vec index ans)
ans)]))]))))))]))
(define memoize/1 (mk-memoize-vec 1))
(define memoize/2 (mk-memoize-vec 2))
;; hash version, but with an extra hash that tells when to evict cache entries
#;
(define (memoize/key f key-fn statsbox)
(let* ([cache-size 50]
[ht (make-hash)]
[uniq (gensym)]
[when-to-evict-table (make-hasheq)]
[pointer 0])
(lambda (x y)
(record-cache-test! statsbox)
(let* ([key (key-fn x y)]
[value-in-cache (hash-ref ht key uniq)])
(cond
[(eq? value-in-cache uniq)
(record-cache-miss! statsbox)
(let ([res (f x y)])
(let ([to-remove (hash-ref when-to-evict-table pointer uniq)])
(unless (eq? uniq to-remove)
(hash-remove! ht to-remove)))
(hash-set! when-to-evict-table pointer key)
(hash-set! ht key res)
(set! pointer (modulo (+ pointer 1) cache-size))
res)]
[else
value-in-cache])))))
;; lru cache
;; for some reason, this seems to hit *less* than the "just dump stuff out" strategy!
#;
(define (memoize/key f key-fn statsbox)
(let* ([cache-size 50]
[cache '()])
(lambda (x y)
(record-cache-test! statsbox)
(let ([key (key-fn x y)])
(cond
[(null? cache)
;; empty cache
(let ([ans (f x y)])
(record-cache-miss! statsbox)
(set! cache (cons (cons key ans) '()))
ans)]
[(null? (cdr cache))
;; one element cache
(if (equal? (car (car cache)) key)
(cdr (car cache))
(let ([ans (f x y)])
(record-cache-miss! statsbox)
(set! cache (cons (cons key ans) cache))
ans))]
[else
;; two of more element cache
(cond
[(equal? (car (car cache)) key)
;; check first element
(cdr (car cache))]
[(equal? (car (cadr cache)) key)
;; check second element
(cdr (cadr cache))]
[else
;; iterate from the 3rd element onwards
(let loop ([previous2 cache]
[previous1 (cdr cache)]
[current (cddr cache)]
[i 0])
(cond
[(null? current)
;; found the end of the cache -- need to drop the last element if the cache is too full,
;; and put the current value at the front of the cache.
(let ([ans (f x y)])
(record-cache-miss! statsbox)
(set! cache (cons (cons key ans) cache))
(unless (< i cache-size)
;; drop the last element from the cache
(set-cdr! previous2 '()))
ans)]
[else
(let ([entry (car current)])
(cond
[(equal? (car entry) key)
;; found a hit
; remove this element from the list where it is.
(set-cdr! previous1 (cdr current))
; move it to the front of the cache
(set! cache (cons current cache))
; return the found element
(cdr entry)]
[else
;; didn't hit yet, continue searching
(loop previous1 current (cdr current) (+ i 1))]))]))])])))))
;; hash version, but with a vector that tells when to evict cache entries
#;
(define (memoize/key f key-fn statsbox)
(let* ([cache-size 50]
[ht (make-hash)]
[uniq (gensym)]
[vector (make-vector cache-size uniq)] ;; vector is only used to evict things from the hash
[pointer 0])
(lambda (x y)
(let* ([key (key-fn x y)]
[value-in-cache (hash-ref ht key uniq)])
(cond
[(eq? value-in-cache uniq)
(let ([res (f x y)])
(let ([to-remove (vector-ref vector pointer)])
(unless (eq? uniq to-remove)
(hash-remove! ht to-remove)))
(vector-set! vector pointer key)
(hash-set! ht key res)
(set! pointer (modulo (+ pointer 1) cache-size))
res)]
[else
value-in-cache])))))
;; vector-based version, with a cleverer replacement strategy
#;
(define (memoize/key f key-fn statsbox)
(let* ([cache-size 20]
;; cache : (vector-of (union #f (cons key val)))
;; the #f correspond to empty spots in the cache
[cache (make-vector cache-size #f)]
[pointer 0])
(lambda (x y)
(let ([key (key-fn x y)])
(let loop ([i 0])
(cond
[(= i cache-size)
(unless (vector-ref cache pointer)
(vector-set! cache pointer (cons #f #f)))
(let ([pair (vector-ref cache pointer)]
[ans (f x y)])
(set-car! pair key)
(set-cdr! pair ans)
(set! pointer (modulo (+ 1 pointer) cache-size))
ans)]
[else
(let ([entry (vector-ref cache i)])
(if entry
(let ([e-key (car entry)]
[e-val (cdr entry)])
(if (equal? e-key key)
e-val
(loop (+ i 1))))
;; if we hit a #f, just skip ahead and store this in the cache
(loop cache-size)))]))))))
;; original version
#;
(define (memoize/key f key-fn statsbox)
(let ([ht (make-hash)]
[entries 0])
(lambda (x y)
(record-cache-test! statsbox)
(let* ([key (key-fn x y)]
[compute/cache
(lambda ()
(set! entries (+ entries 1))
(record-cache-miss! statsbox)
(let ([res (f x y)])
(hash-set! ht key res)
res))])
(unless (< entries 200) ; 10000 was original size
(set! entries 0)
(set! ht (make-hash)))
(hash-ref ht key compute/cache)))))
(define (record-cache-miss! statsbox)
(set-cache-stats-hits! statsbox (sub1 (cache-stats-hits statsbox)))
(set-cache-stats-misses! statsbox (add1 (cache-stats-misses statsbox))))
(define (record-cache-test! statsbox)
(set-cache-stats-hits! statsbox (add1 (cache-stats-hits statsbox))))
(define (record-cache-clobber! statsbox)
(set-cache-stats-clobber-hits! statsbox (add1 (cache-stats-clobber-hits statsbox))))
(define-struct cache-stats (name misses hits clobber-hits sizes) #:mutable)
(define (new-cache-stats name) (make-cache-stats name 0 0 0 '()))
(define w/hole (new-cache-stats "hole"))
(define nohole (new-cache-stats "no-hole"))
(define (record-cache-size! cache-stats cache)
(define size
(let loop ([cache cache])
(cond
[(vector? cache)
(for/fold ([size (vector-length cache)])
([ele (in-vector cache)])
(+ size (loop ele)))]
[(pair? cache)
(+ 1 (loop (car cache)) (loop (cdr cache)))]
[else 1])))
(set-cache-stats-sizes! cache-stats (cons size (cache-stats-sizes cache-stats))))
(define (print-stats)
(let ((stats (list w/hole nohole)))
(for-each
(lambda (s)
(when (> (+ (cache-stats-hits s) (cache-stats-misses s)) 0)
(printf "~a has ~a hits, ~a misses (~a% miss rate)\n"
(cache-stats-name s)
(cache-stats-hits s)
(cache-stats-misses s)
(floor
(* 100 (/ (cache-stats-misses s)
(+ (cache-stats-hits s) (cache-stats-misses s))))))))
stats)
(let ((overall-hits (apply + (map cache-stats-hits stats)))
(overall-miss (apply + (map cache-stats-misses stats)))
(overall-clobber-hits (apply + (map cache-stats-clobber-hits stats))))
(printf "---\nOverall hits: ~a\n" overall-hits)
(printf "Overall misses: ~a\n" overall-miss)
(when (> (+ overall-hits overall-miss) 0)
(printf "Overall miss rate: ~a%\n"
(floor (* 100 (/ overall-miss (+ overall-hits overall-miss))))))
(printf "Overall clobbering hits: ~a\n" overall-clobber-hits))
(let* ([sizes (apply append (map cache-stats-sizes stats))]
[len (length sizes)])
(unless (zero? len)
(let ([avg (/ (apply + 0.0 sizes) len)])
(printf "Average cache size ~s; ~a samples\n" avg len))))))
;; match-hole : compiled-pattern
(define match-hole
(λ (exp hole-info)
(if hole-info
(list (make-mtch empty-bindings
the-hole
exp))
(and (hole? exp)
(list (make-mtch empty-bindings
the-hole
none))))))
;; match-in-hole : sexp sexp sexp compiled-pattern compiled-pattern -> compiled-pattern
(define (match-in-hole context contractum exp match-context match-contractum)
(λ (exp old-hole-info)
(let ([mtches (match-context exp #t)])
(and mtches
(let loop ([mtches mtches]
[acc null])
(cond
[(null? mtches)
(if (null? acc)
#f
acc)]
[else
(let* ([mtch (car mtches)]
[bindings (mtch-bindings mtch)]
[hole-exp (mtch-hole mtch)]
[contractum-mtches (match-contractum hole-exp old-hole-info)])
(when (eq? none hole-exp)
(error 'matcher.rkt "found no hole when matching a decomposition"))
(if contractum-mtches
(let i-loop ([contractum-mtches contractum-mtches]
[acc acc])
(cond
[(null? contractum-mtches) (loop (cdr mtches) acc)]
[else (let* ([contractum-mtch (car contractum-mtches)]
[contractum-bindings (mtch-bindings contractum-mtch)])
(i-loop
(cdr contractum-mtches)
(cons
(make-mtch (make-bindings
(append (bindings-table contractum-bindings)
(bindings-table bindings)))
(build-nested-context
(mtch-context mtch)
(mtch-context contractum-mtch))
(mtch-hole contractum-mtch))
acc)))]))
(loop (cdr mtches) acc)))]))))))
(define (match-in-hole/contractum-boolean context contractum exp match-context match-contractum)
(λ (exp)
(let ([mtches (match-context exp #t)])
(and mtches
(let loop ([mtches mtches])
(cond
[(null? mtches) #f]
[else
(let* ([mtch (car mtches)]
[hole-exp (mtch-hole mtch)]
[contractum-mtches (match-contractum hole-exp)])
(when (eq? none hole-exp)
(error 'matcher.rkt "found no hole when matching a decomposition"))
(or contractum-mtches
(loop (cdr mtches))))]))))))
;; match-list/boolean : (listof (union repeat (any hole-info -> boolean))) sexp hole-info -> boolean
(define (match-list/boolean patterns exp)
(let loop ([exp exp]
[patterns patterns])
(cond
[(null? exp)
(let loop ([patterns patterns])
(or (null? patterns)
(and (repeat? (car patterns))
(loop (cdr patterns)))))]
[(null? patterns) #f]
[(repeat? (car patterns))
(or (loop exp (cdr patterns))
(and ((repeat-pat (car patterns)) (car exp))
(loop (cdr exp) patterns)))]
[else
(and ((car patterns) (car exp))
(loop (cdr exp) (cdr patterns)))])))
;; match-list : (listof (union repeat compiled-pattern)) sexp hole-info -> (union #f (listof bindings))
(define (match-list patterns exp hole-info)
(let (;; raw-match : (listof (listof (listof mtch)))
[raw-match (match-list/raw patterns exp hole-info)])
(and (not (null? raw-match))
(let loop ([raw-match raw-match])
(cond
[(null? raw-match) '()]
[else (append (combine-matches (car raw-match))
(loop (cdr raw-match)))])))))
;; match-list/raw : (listof (union repeat compiled-pattern))
;; sexp
;; hole-info
;; -> (listof (listof (listof mtch)))
;; the result is the raw accumulation of the matches for each subpattern, as follows:
;; (listof (listof (listof mtch)))
;; \ \ \-------------/ a match for one position in the list (failures don't show up)
;; \ \-------------------/ one element for each position in the pattern list
;; \-------------------------/ one element for different expansions of the ellipses
;; the failures to match are just removed from the outer list before this function finishes
;; via the `fail' argument to `loop'.
(define (match-list/raw patterns exp hole-info)
(let/ec k
(let loop ([patterns patterns]
[exp exp]
;; fail : -> alpha
;; causes one possible expansion of ellipses to fail
;; initially there is only one possible expansion, so
;; everything fails.
[fail (lambda () (k null))])
(cond
[(pair? patterns)
(let ([fst-pat (car patterns)])
(cond
[(repeat? fst-pat)
(if (or (null? exp) (pair? exp))
(let ([r-pat (repeat-pat fst-pat)]
[r-mt (make-mtch (make-bindings (repeat-empty-bindings fst-pat))
(build-flat-context '())
none)])
(apply
append
(cons (let/ec k
(let ([mt-fail (lambda () (k null))])
(map (lambda (pat-ele)
(cons (add-ellipses-index (list r-mt) (repeat-name fst-pat) (repeat-mismatch fst-pat) 0)
pat-ele))
(loop (cdr patterns) exp mt-fail))))
(let r-loop ([exp exp]
;; past-matches is in reverse order
;; it gets reversed before put into final list
[past-matches (list r-mt)]
[index 1])
(cond
[(pair? exp)
(let* ([fst (car exp)]
[m (r-pat fst hole-info)])
(if m
(let* ([combined-matches (collapse-single-multiples m past-matches)]
[reversed
(add-ellipses-index
(reverse-multiples combined-matches)
(repeat-name fst-pat)
(repeat-mismatch fst-pat)
index)])
(cons
(let/ec fail-k
(map (lambda (x) (cons reversed x))
(loop (cdr patterns)
(cdr exp)
(lambda () (fail-k null)))))
(r-loop (cdr exp)
combined-matches
(+ index 1))))
(list null)))]
;; what about dotted pairs?
[else (list null)])))))
(fail))]
[else
(cond
[(pair? exp)
(let* ([fst-exp (car exp)]
[match (fst-pat fst-exp hole-info)])
(if match
(let ([exp-match (map (λ (mtch) (make-mtch (mtch-bindings mtch)
(build-list-context (mtch-context mtch))
(mtch-hole mtch)))
match)])
(map (lambda (x) (cons exp-match x))
(loop (cdr patterns) (cdr exp) fail)))
(fail)))]
[else
(fail)])]))]
[else
(if (null? exp)
(list null)
(fail))]))))
(define null-match (list (make-mtch (make-bindings '()) '() none)))
(define (match-list/no-repeats patterns exp hole-info)
(define (match-list/raw/no-repeats/no-ambiguity patterns exp hole-info)
(let/ec k
(define-values (bindings lst hole)
(let loop ([patterns patterns]
[exp exp])
(cond
[(pair? patterns)
(let ([fst-pat (car patterns)])
(cond
[(pair? exp)
(let* ([fst-exp (car exp)]
[fst-mtchs (fst-pat fst-exp hole-info)])
(cond
[(not fst-mtchs) (k #f)]
[(null? (cdr fst-mtchs))
(define mtch1 (car fst-mtchs))
(define-values (bindings lst hole) (loop (cdr patterns) (cdr exp)))
(define new-bindings (bindings-table (mtch-bindings mtch1)))
(values (append new-bindings bindings)
(build-cons-context (mtch-context mtch1) lst)
(pick-hole (mtch-hole mtch1) hole))]
[else
(error 'ack)]))]
[else (k #f)]))]
[else
(if (null? exp)
(values '() '() none)
(k #f))])))
(list (make-mtch (make-bindings bindings) lst hole))))
(define (match-list/raw/no-repeats patterns exp hole-info)
(let/ec k
(let loop ([patterns patterns]
[exp exp])
(cond
[(pair? patterns)
(let ([fst-pat (car patterns)])
(cond
[(pair? exp)
(let* ([fst-exp (car exp)]
[fst-mtchs (fst-pat fst-exp hole-info)])
(cond
[fst-mtchs
(define rst-mtchs (loop (cdr patterns) (cdr exp)))
(cond
[rst-mtchs
(combine-pair/no-repeat fst-mtchs rst-mtchs)]
[else
(k #f)])]
[else (k #f)]))]
[else (k #f)]))]
[else
(if (null? exp)
null-match
(k #f))]))))
;; combine-pair : (listof mtch) (listof mtch) -> (listof mtch)
(define (combine-pair/no-repeat fst snd)
(let ([mtchs null])
(for-each
(lambda (mtch1)
(for-each
(lambda (mtch2)
(set! mtchs (cons (make-mtch
(make-bindings (append (bindings-table (mtch-bindings mtch1))
(bindings-table (mtch-bindings mtch2))))
(build-cons-context (mtch-context mtch1) (mtch-context mtch2))
(pick-hole (mtch-hole mtch1)
(mtch-hole mtch2)))
mtchs)))
snd))
fst)
mtchs))
;(match-list/raw/no-repeats/no-ambiguity patterns exp hole-info)
(match-list/raw/no-repeats patterns exp hole-info)
)
;; add-ellipses-index : (listof mtch) (or/c sym #f) (or/c sym #f) number -> (listof mtch)
(define (add-ellipses-index mtchs name mismatch-name i)
(let* ([ribs '()]
[ribs (if name
(cons (make-bind name i) ribs)
ribs)]
[ribs (if mismatch-name
(cons (make-mismatch-bind mismatch-name i) ribs)
ribs)])
(map (λ (mtch) (make-mtch (make-bindings (append ribs (bindings-table (mtch-bindings mtch))))
(mtch-context mtch)
(mtch-hole mtch)))
mtchs)))
;; collapse-single-multiples : (listof mtch) (listof mtch[to-lists]) -> (listof mtch[to-lists])
(define (collapse-single-multiples bindingss multiple-bindingss)
(apply append
(map
(lambda (multiple-match)
(let ([multiple-bindings (mtch-bindings multiple-match)])
(map
(lambda (single-match)
(let ([single-bindings (mtch-bindings single-match)])
(make-mtch (make-bindings
(map (match-lambda*
[`(,(struct bind (name sing-exp)) ,(struct bind (name mult-exp)))
(make-bind name (cons sing-exp mult-exp))]
[`(,(struct mismatch-bind (name sing-exp)) ,(struct mismatch-bind (name mult-exp)))
(make-mismatch-bind name (cons sing-exp mult-exp))]
[else
(error 'collapse-single-multiples
"internal error: expected matches' bindings in same order; got\n ~e\n ~e"
single-bindings
multiple-bindings)])
(bindings-table single-bindings)
(bindings-table multiple-bindings)))
(build-cons-context
(mtch-context single-match)
(mtch-context multiple-match))
(pick-hole (mtch-hole single-match)
(mtch-hole multiple-match)))))
bindingss)))
multiple-bindingss)))
;; pick-hole : (union none sexp) (union none sexp) -> (union none sexp)
(define (pick-hole s1 s2)
(cond
[(eq? none s1) s2]
[(eq? none s2) s1]
[(error 'matcher.rkt "found two holes")]))
;; reverse-multiples : (listof mtch[to-lists]) -> (listof mtch[to-lists])
;; reverses the rhs of each rib in the bindings and reverses the context.
(define (reverse-multiples matches)
(map (lambda (match)
(let ([bindings (mtch-bindings match)])
(make-mtch
(make-bindings
(map (lambda (rib)
(cond
[(bind? rib)
(make-bind (bind-name rib)
(reverse (bind-exp rib)))]
[(mismatch-bind? rib)
(make-mismatch-bind (mismatch-bind-name rib)
(reverse (mismatch-bind-exp rib)))]))
(bindings-table bindings)))
(reverse-context (mtch-context match))
(mtch-hole match))))
matches))
;; match-nt : (listof compiled-rhs) (listof compiled-rhs) sym exp hole-info
;; -> (union #f (listof bindings))
(define (match-nt list-rhs non-list-rhs nt term hole-info)
(if hole-info
(let loop ([rhss (if (or (null? term) (pair? term))
list-rhs
non-list-rhs)]
[ans '()])
(cond
[(null? rhss)
(if (null? ans)
#f
(begin
(when (check-redudancy)
(let ([rd (remove-duplicates ans)])
(unless (= (length rd) (length ans))
(eprintf "found redundancy when matching the non-terminal ~s against:\n~s~a"
nt
term
(apply
string-append
(map (λ (x) (format "\n ~s" x))
ans))))))
ans))]
[else
(let ([mth (call-nt-proc/bindings (car rhss) term hole-info)])
(cond
[mth
(loop (cdr rhss) (append mth ans))]
[else
(loop (cdr rhss) ans)]))]))
;; if we're not doing a decomposition, we just need
;; to find the first match, not all of the matches
(let loop ([rhss (if (or (null? term) (pair? term))
list-rhs
non-list-rhs)])
(cond
[(null? rhss) #f]
[else
(or (call-nt-proc/bindings (car rhss) term hole-info)
(loop (cdr rhss)))]))))
(define check-redudancy (make-parameter #f))
(define (match-nt/boolean list-rhs non-list-rhs nt term)
(let loop ([rhss (if (or (null? term) (pair? term))
list-rhs
non-list-rhs)])
(cond
[(null? rhss) #f]
[else
(or (call-nt-proc/bool (compiled-pattern-cp (car rhss)) term)
(loop (cdr rhss)))])))
(define (call-nt-proc/bool nt-proc exp)
(if (procedure-arity-includes? nt-proc 1)
(nt-proc exp)
(and (remove-bindings/filter (nt-proc exp #f)) #t)))
(define (call-nt-proc/bindings compiled-pattern exp hole-info)
(define nt-proc (compiled-pattern-cp compiled-pattern))
(define skip-dup? (compiled-pattern-skip-dup-check? compiled-pattern))
(define has-names? (compiled-pattern-binds-names? compiled-pattern))
(cond
[(procedure-arity-includes? nt-proc 1)
(and (nt-proc exp)
(list (make-mtch empty-bindings
(build-flat-context exp)
none)))]
[skip-dup?
(define res (nt-proc exp hole-info))
(and res
(not (null? res))
(if has-names?
(map (λ (match)
(make-mtch empty-bindings
(mtch-context match)
(mtch-hole match)))
res)
res))]
[else
(remove-bindings/filter (nt-proc exp hole-info))]))
;; remove-bindings/filter : (union #f (listof mtch)) -> (union #f (listof mtch))
(define (remove-bindings/filter matches)
(and matches
(let ([filtered (filter-multiples matches)])
;(printf ">> ~s\n=> ~s\n\n" matches filtered)
(and (not (null? filtered))
(map (λ (match)
(make-mtch empty-bindings
(mtch-context match)
(mtch-hole match)))
matches)))))
;; rewrite-ellipses : (listof l-pat)
;; (pattern -> (values compiled-pattern boolean))
;; -> (values (listof (union repeat compiled-pattern)) boolean)
;; moves the ellipses out of the list and produces repeat structures
(define (rewrite-ellipses pattern compile)
(define (maybe-cons hd tl) (if hd (cons hd tl) tl))
(let loop ([exp-eles pattern])
(match exp-eles
[`() (values empty empty empty empty)]
[(cons `(repeat ,pat ,name ,mismatch-name) rst)
(define-values (fst-compiled fst-has-hole? fst-has-hide-hole? fst-names) (compile pat))
(define-values (rst-compiled rst-has-hole? rst-has-hide-hole? rst-names) (loop rst))
(values (cons (make-repeat fst-compiled
(extract-empty-bindings pat)
name
mismatch-name)
rst-compiled)
(cons fst-has-hole? rst-has-hole?)
(cons (or fst-has-hide-hole? name mismatch-name) rst-has-hide-hole?)
(cons (maybe-cons name (maybe-cons (and mismatch-name `(mismatch , mismatch-name))
fst-names))
rst-names))]
[(cons pat rst)
(define-values (fst-compiled fst-has-hole? fst-has-hide-hole? fst-names) (compile pat))
(define-values (rst-compiled rst-has-hole? rst-has-hide-hole? rst-names) (loop rst))
(values (cons fst-compiled rst-compiled)
(cons fst-has-hole? rst-has-hole?)
(cons fst-has-hide-hole? rst-has-hide-hole?)
(cons fst-names rst-names))])))
(define (prefixed-with? prefix exp)
(and (symbol? exp)
(let* ([str (symbol->string exp)]
[len (string-length str)])
(and (len . >= . (string-length prefix))
(string=? (substring str 0 (string-length prefix))
prefix)))))
(define dummy (box 0))
;; extract-empty-bindings : pattern -> (listof rib)
(define (extract-empty-bindings pattern)
(let loop ([pattern pattern]
[ribs null])
(match-a-pattern pattern
[`any ribs]
[`number ribs]
[`string ribs]
[`natural ribs]
[`integer ribs]
[`real ribs]
[`variable ribs]
[`(variable-except ,vars ...) ribs]
[`(variable-prefix ,vars) ribs]
[`variable-not-otherwise-mentioned ribs]
[`hole ribs]
[`(nt ,nt) ribs]
[`(name ,name ,pat)
(cons (make-bind name '()) (loop pat ribs))]
[`(mismatch-name ,name ,pat)
(cons (make-mismatch-bind name '()) (loop pat ribs))]
[`(in-hole ,context ,contractum) (loop contractum (loop context ribs))]
[`(hide-hole ,p) (loop p ribs)]
[`(side-condition ,pat ,test ,expr) (loop pat ribs)]
[`(cross ,id) ribs]
[`(list ,pats ...)
(let-values ([(rewritten has-hole? has-hide-hole? names)
(rewrite-ellipses pats (lambda (x) (values x #f #f '())))])
(let i-loop ([r-exps rewritten]
[ribs ribs])
(cond
[(null? r-exps) ribs]
[else (let ([r-exp (car r-exps)])
(cond
[(repeat? r-exp)
(define bindings (if (repeat-mismatch r-exp)
(list (make-mismatch-bind (repeat-mismatch r-exp) '()))
'()))
(define bindings2 (if (repeat-name r-exp)
(cons (make-bind (repeat-name r-exp) '()) bindings)
bindings))
(append bindings2
(repeat-empty-bindings r-exp)
(i-loop (cdr r-exps) ribs))]
[else
(loop (car r-exps) (i-loop (cdr r-exps) ribs))]))])))]
[(? (compose not pair?)) ribs])))
;; combine-matches : (listof (listof mtch)) -> (listof mtch)
;; input is the list of bindings corresonding to a piecewise match
;; of a list. produces all of the combinations of complete matches
(define (combine-matches matchess)
(let loop ([matchess matchess])
(cond
[(null? matchess) combine-matches-base-case]
[else (combine-pair (car matchess) (loop (cdr matchess)))])))
;; this 'inlines' build-flat-context so that the definition can remain here, near where it is used.
(define combine-matches-base-case (list (make-mtch empty-bindings
'() #;(build-flat-context '())
none)))
;; combine-pair : (listof mtch) (listof mtch) -> (listof mtch)
(define (combine-pair fst snd)
(let ([mtchs null])
(for-each
(lambda (mtch1)
(for-each
(lambda (mtch2)
(set! mtchs (cons (make-mtch
(make-bindings (append (bindings-table (mtch-bindings mtch1))
(bindings-table (mtch-bindings mtch2))))
(build-append-context (mtch-context mtch1) (mtch-context mtch2))
(pick-hole (mtch-hole mtch1)
(mtch-hole mtch2)))
mtchs)))
snd))
fst)
mtchs))
(define (hash-maps? ht key)
(not (eq? (hash-ref ht key uniq) uniq)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; context adt
;;
#|
;; This version of the ADT isn't right yet --
;; need to figure out what to do about (name ...) patterns.
(define-values (struct:context make-context context? context-ref context-set!)
(make-struct-type 'context #f 1 0 #f '() #f 0))
(define hole values)
(define (build-flat-context exp) (make-context (lambda (x) exp)))
(define (build-cons-context c1 c2) (make-context (lambda (x) (cons (c1 x) (c2 x)))))
(define (build-append-context l1 l2) (make-context (lambda (x) (append (l1 x) (l2 x)))))
(define (build-list-context l) (make-context (lambda (x) (list (l x)))))
(define (build-nested-context c1 c2) (make-context (lambda (x) (c1 (c2 x)))))
(define (plug exp hole-stuff) (exp hole-stuff))
(define (reverse-context c) (make-context (lambda (x) (reverse (c x)))))
|#
(define (context? x) #t)
(define-values (the-hole the-not-hole hole?)
(let ()
(define-struct hole (id)
#:property prop:equal+hash (list (λ (x y recur) #t) (λ (v recur) 255) (λ (v recur) 65535))
#:inspector #f)
(define the-hole (make-hole 'the-hole))
(define the-not-hole (make-hole 'the-not-hole))
(values the-hole the-not-hole hole?)))
(define (hole->not-hole exp)
(let loop ([exp exp])
(cond
[(pair? exp)
(define old-car (car exp))
(define new-car (loop old-car))
(cond
[(eq? new-car old-car)
(define old-cdr (cdr exp))
(define new-cdr (loop old-cdr))
(if (eq? new-cdr old-cdr)
exp
(cons new-car new-cdr))]
[else (cons new-car (cdr exp))])]
[(eq? exp the-hole)
the-not-hole]
[else exp])))
(define (build-flat-context exp) exp)
(define (build-cons-context e1 e2) (cons e1 e2))
(define (build-append-context e1 e2) (append e1 e2))
(define (build-list-context x) (list x))
(define (reverse-context x) (reverse x))
(define (build-nested-context c1 c2)
(plug c1 c2))
(define (plug exp hole-stuff)
(let loop ([exp exp])
(cond
[(pair? exp)
(define old-car (car exp))
(define new-car (loop old-car))
(cond
[(eq? new-car old-car)
(define old-cdr (cdr exp))
(define new-cdr (loop old-cdr))
(if (eq? new-cdr old-cdr)
exp
(cons new-car new-cdr))]
[else (cons new-car (cdr exp))])]
[(eq? the-not-hole exp)
the-not-hole]
[(eq? the-hole exp)
hole-stuff]
[else exp])))
;;
;; end context adt
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; used in hash lookups to tell when something isn't in the table
(define uniq (gensym))
(provide/contract
(match-pattern (compiled-pattern? any/c . -> . (or/c false/c (listof mtch?))))
(match-pattern? (compiled-pattern? any/c . -> . boolean?))
(compile-pattern (-> compiled-lang? any/c boolean?
compiled-pattern?))
(set-cache-size! (-> (and/c integer? positive?) void?))
(cache-size (and/c integer? positive?))
(mtch? predicate/c)
(make-mtch (bindings? any/c any/c . -> . mtch?))
(mtch-bindings (mtch? . -> . bindings?))
(mtch-context (mtch? . -> . any/c))
(mtch-hole (mtch? . -> . (or/c none? any/c)))
(make-bindings ((listof bind?) . -> . bindings?))
(bindings-table (bindings? . -> . (listof bind?)))
(bindings? predicate/c)
(make-bind (symbol? any/c . -> . bind?))
(bind? predicate/c)
(bind-name (bind? . -> . symbol?))
(bind-exp (bind? . -> . any/c))
(compile-language (-> any/c (listof nt?) (listof (listof symbol?)) compiled-lang?)))
(provide compiled-pattern?
print-stats)
;; for test suite
(provide build-cons-context
build-flat-context
context?
extract-empty-bindings
(rename-out [bindings-table bindings-table-unchecked])
(struct-out mismatch-bind)
(struct-out compiled-pattern))
(provide (struct-out nt)
(struct-out rhs)
(struct-out compiled-lang)
compiled-lang-cclang
lookup-binding
compiled-pattern
plug
none? none
make-repeat
the-not-hole the-hole hole?
rewrite-ellipses
build-compatible-context-language
caching-enabled?
check-redudancy
prefix-nts)