racket/collects/syntax/private/stxparse/rep.rkt

1220 lines
45 KiB
Racket

#lang racket/base
(require (for-template racket/base)
(for-template "runtime.ss")
racket/contract/base
"minimatch.ss"
racket/dict
syntax/id-table
syntax/stx
syntax/keyword
unstable/syntax
unstable/struct
"../util/txlift.ss"
"rep-data.ss"
"codegen-data.ss")
;; Error reporting
;; All entry points should have explicit, mandatory #:context arg
;; (mandatory from outside, at least)
(provide/contract
[parse-rhs
(-> syntax? (or/c false/c (listof sattr?)) boolean? #:context (or/c false/c syntax?)
rhs?)]
[parse-whole-pattern
(-> syntax? DeclEnv/c #:context (or/c false/c syntax?)
pattern?)]
[parse-pattern-directives
(-> stx-list?
#:allow-declare? boolean?
#:decls (or/c false/c DeclEnv/c)
#:context (or/c false/c syntax?)
(values stx-list? DeclEnv/c (listof syntax?) (listof SideClause/c)))]
[parse-directive-table any/c]
[get-decls+defs
(-> list? boolean? #:context (or/c false/c syntax?)
(values DeclEnv/c (listof syntax?)))]
#|
[decls-create-defs
(-> DeclEnv/c
(values DeclEnv/c (listof syntax?)))]
|#
[create-aux-def
(-> DeclEntry/c
(values DeclEntry/c (listof syntax?)))]
#|
[check-literals-list
;; NEEDS txlift context
(-> syntax? syntax?
(listof (list/c identifier? identifier? ct-phase/c ct-phase/c)))]
|#
[check-literals-list/litset
(-> syntax? syntax?
(listof (list/c identifier? identifier?)))]
#|
[check-literal-sets-list
;; NEEDS txlift context
(-> syntax? syntax?
(listof (listof (list/c identifier? identifier? ct-phase/c))))]
|#
[check-conventions-rules
(-> syntax? syntax?
(listof (list/c regexp? any/c)))])
(define (atomic-datum? stx)
(let ([datum (syntax-e stx)])
(or (null? datum)
(boolean? datum)
(string? datum)
(number? datum)
(keyword? datum))))
(define (id-predicate kw)
(lambda (stx)
(and (identifier? stx)
(free-identifier=? stx kw)
(begin (disappeared! stx) #t))))
(define wildcard? (id-predicate (quote-syntax _)))
(define epsilon? (id-predicate (quote-syntax ||)))
(define dots? (id-predicate (quote-syntax ...)))
(define plus-dots? (id-predicate (quote-syntax ...+)))
(define keywords
(list (quote-syntax _)
(quote-syntax ||)
(quote-syntax ...)
(quote-syntax ~var)
(quote-syntax ~datum)
(quote-syntax ~literal)
(quote-syntax ~and)
(quote-syntax ~or)
(quote-syntax ~not)
(quote-syntax ~seq)
(quote-syntax ~rep)
(quote-syntax ~once)
(quote-syntax ~optional)
(quote-syntax ~between)
(quote-syntax ~rest)
(quote-syntax ~describe)
(quote-syntax ~!)
(quote-syntax ~bind)
(quote-syntax ~fail)
(quote-syntax ~early-fail)
(quote-syntax ~parse)
(quote-syntax ...+)))
(define (reserved? stx)
(and (identifier? stx)
(for/or ([kw keywords])
(free-identifier=? stx kw))))
(define (safe-name? stx)
(and (identifier? stx)
(not (regexp-match? #rx"^~" (symbol->string (syntax-e stx))))))
;; ---
(define (disappeared! x)
(cond [(identifier? x)
(record-disappeared-uses (list x))]
[(and (stx-pair? x) (identifier? (stx-car x)))
(record-disappeared-uses (list (stx-car x)))]
[else
(raise-type-error 'disappeared!
"identifier or syntax with leading identifier"
x)]))
;; ---
;; parse-rhs : stx boolean (or #f (listof SAttr)) stx -> RHS
;; If expected-attrs is true, then referenced stxclasses must be defined and
;; literals must be bound. Set to #f for pass1 (attr collection);
;; parser requires stxclasses to be bound.
(define (parse-rhs stx expected-attrs splicing? #:context ctx)
(call/txlifts
(lambda ()
(parameterize ((current-syntax-context ctx))
(define-values (rest description transp? attributes auto-nested?
decls defs commit?)
(parse-rhs/part1 stx splicing? (and expected-attrs #t)))
(define patterns
(parameterize ((stxclass-lookup-config
(cond [expected-attrs 'yes]
[auto-nested? 'try]
[else 'no])))
(parse-variants rest decls splicing? expected-attrs)))
(when (null? patterns)
(wrong-syntax #f "expected at least one variant"))
(let ([sattrs
(or attributes
(intersect-sattrss (map variant-attrs patterns)))])
(make rhs stx sattrs transp? description patterns
(append (get-txlifts-as-definitions) defs)
commit?))))))
(define (parse-rhs/part1 stx splicing? strict?)
(define-values (chunks rest)
(parse-keyword-options stx rhs-directive-table
#:context (current-syntax-context)
#:incompatible '((#:attributes #:auto-nested-attributes))
#:no-duplicates? #t))
(define description (options-select-value chunks '#:description #:default #f))
(define opaque? (and (assq '#:opaque chunks) #t))
(define transparent? (not opaque?))
(define auto-nested? (and (assq '#:auto-nested-attributes chunks) #t))
(define commit? ;; FIXME: default value should be (not splicing?) once this works
(options-select-value chunks '#:commit? #:default #t))
(define attributes (options-select-value chunks '#:attributes #:default #f))
(define-values (decls defs) (get-decls+defs chunks strict?))
(values rest description transparent? attributes auto-nested? decls defs commit?))
(define (parse-variants rest decls splicing? expected-attrs)
(define (gather-patterns stx)
(syntax-case stx (pattern)
[((pattern . _) . rest)
(begin (disappeared! (stx-car stx))
(cons (parse-variant (stx-car stx) splicing? decls expected-attrs)
(gather-patterns #'rest)))]
[(bad-variant . rest)
(wrong-syntax #'bad-variant "expected syntax-class variant")]
[()
null]))
(gather-patterns rest))
;; get-decls+defs : chunks boolean -> (values DeclEnv (listof syntax))
(define (get-decls+defs chunks strict?
#:context [ctx (current-syntax-context)])
(parameterize ((current-syntax-context ctx))
(let*-values ([(decls defs1) (get-decls chunks strict?)]
[(decls defs2) (decls-create-defs decls)])
(values decls (append defs1 defs2)))))
;; get-decls : chunks -> (values DeclEnv (listof syntax))
(define (get-decls chunks strict?)
(define lits (options-select-value chunks '#:literals #:default null))
(define litsets (options-select-value chunks '#:literal-sets #:default null))
(define convs (options-select-value chunks '#:conventions #:default null))
(define localconvs (options-select-value chunks '#:local-conventions #:default null))
(define literals
(append-lits+litsets lits litsets))
(define-values (convs-rules convs-defs)
(for/fold ([convs-rules null] [convs-defs null])
([conv-entry convs])
(let* ([c (car conv-entry)]
[args (cdr conv-entry)]
[get-parser-id (conventions-get-procedures c)]
[rules ((conventions-get-rules c))])
(values (append rules convs-rules)
(cons (make-conventions-def (map cadr rules) get-parser-id args)
convs-defs)))))
(define convention-rules (append localconvs convs-rules))
(values (new-declenv literals #:conventions convention-rules)
(reverse convs-defs)))
;; make-conventions-def : (listof den:delay) id (listof syntax) -> syntax
(define (make-conventions-def dens get-procedures-id args)
(with-syntax ([(parser ...) (map den:delayed-parser dens)]
[get-procedures get-procedures-id]
[(arg ...) args])
#'(define-values (parser ...)
(let-values ([(parsers descriptions) (get-procedures arg ...)])
(apply values parsers)))))
;; decls-create-defs : DeclEnv -> (values DeclEnv (listof stx))
(define (decls-create-defs decls0)
(define (updater key value defs)
(let-values ([(value newdefs) (create-aux-def value)])
(values value (append newdefs defs))))
(declenv-update/fold decls0 updater null))
;; create-aux-def : DeclEntry -> (values DeclEntry (listof stx))
;; FIXME: replace with txlift mechanism
(define (create-aux-def entry)
(match entry
[(struct den:lit (_i _e _ip _lp))
(values entry null)]
[(struct den:class (name class args))
(cond [(identifier? name)
(let ([sc (get-stxclass/check-arg-count class (length args))])
(with-syntax ([sc-parser (stxclass-parser-name sc)]
[sc-description (stxclass-description sc)])
(with-syntax ([parser (generate-temporary class)]
[description (generate-temporary class)])
(values (make den:parser #'parser #'description
(stxclass-attrs sc) (stxclass/h? sc)
(stxclass-commit? sc))
(list #`(define-values (parser description)
(curried-stxclass-procedures
#,class #,args)))))))]
[(regexp? name)
;; Conventions rule; delay class lookup until module/intdefs pass2
;; to allow forward references
(with-syntax ([parser (generate-temporary class)]
[description (generate-temporary class)])
(values (make den:delayed #'parser #'description class)
(list #`(define-values (parser description)
(curried-stxclass-procedures
#,class #,args)))))])]
[(struct den:parser (_p _d _a _sp _c))
(values entry null)]
[(struct den:delayed (_p _d _c))
(values entry null)]))
(define (append-lits+litsets lits litsets)
(define seen (make-bound-id-table lits))
(for ([litset litsets])
(for ([lit litset])
(when (bound-id-table-ref seen (car lit) #f)
(wrong-syntax (car lit) "duplicate literal declaration"))
(bound-id-table-set! seen (car lit) #t)))
(apply append lits litsets))
;; parse-variant : stx boolean DeclEnv #f/(listof Sattr) -> RHS
(define (parse-variant stx splicing? decls0 expected-attrs)
(syntax-case stx (pattern)
[(pattern p . rest)
(let-values ([(rest decls defs clauses)
(parse-pattern-directives #'rest
#:allow-declare? #t
#:decls decls0)])
(disappeared! stx)
(unless (stx-null? rest)
(wrong-syntax (if (pair? rest) (car rest) rest)
"unexpected terms after pattern directives"))
(let* ([pattern
(parse-whole-pattern #'p decls splicing?)]
[attrs
(append-iattrs
(cons (pattern-attrs pattern)
(side-clauses-attrss clauses)))]
[sattrs (iattrs->sattrs attrs)])
(when expected-attrs
(parameterize ((current-syntax-context stx))
;; Called just for error-reporting
(reorder-iattrs expected-attrs attrs)))
(make variant stx sattrs pattern clauses defs)))]))
(define (side-clauses-attrss clauses)
(for/list ([c clauses]
#:when (or (clause:with? c) (clause:attr? c)))
(if (clause:with? c)
(pattern-attrs (clause:with-pattern c))
(list (clause:attr-attr c)))))
;; parse-whole-pattern : stx DeclEnv boolean -> Pattern
(define (parse-whole-pattern stx decls [splicing? #f]
#:context [ctx (current-syntax-context)])
(parameterize ((current-syntax-context ctx))
(define pattern
(if splicing?
(parse-head-pattern stx decls)
(parse-single-pattern stx decls)))
(define pvars (map attr-name (pattern-attrs pattern)))
(define excess-domain (declenv-domain-difference decls pvars))
(when (pair? excess-domain)
(wrong-syntax #f "declared pattern variables do not appear in pattern"
#:extra excess-domain))
pattern))
;; ----
;; parse-single-pattern : stx DeclEnv -> SinglePattern
(define (parse-single-pattern stx decls)
;; FIXME: allow ghosts, convert to single-term pattern???
(let ([p (parse-*-pattern stx decls #f #f)])
p))
;; parse-head-pattern : stx DeclEnv -> HeadPattern
(define (parse-head-pattern stx decls)
(parse-*-pattern stx decls #t #f))
;; parse-*-pattern : stx DeclEnv boolean boolean -> Pattern
(define (parse-*-pattern stx decls allow-head? allow-ghost?)
(define (check-head! x)
(unless allow-head?
(wrong-syntax stx "head pattern not allowed here"))
x)
(define (check-ghost! x)
;; Coerce to S-pattern IF only S-patterns allowed
(cond [allow-ghost? x]
[(not allow-head?) (ghost-pattern->single-pattern x)]
[else
(wrong-syntax stx "action pattern not allowed here")]))
(syntax-case stx (~var ~literal ~datum ~and ~or ~not ~rest ~describe
~seq ~optional ~! ~bind ~fail ~early-fail ~parse)
[wildcard
(wildcard? #'wildcard)
(begin (disappeared! stx)
(create-pat:any))]
[~!
(disappeared! stx)
(check-ghost!
(create-ghost:cut))]
[reserved
(reserved? #'reserved)
(wrong-syntax stx "pattern keyword not allowed here")]
[id
(identifier? #'id)
(parse-pat:id stx decls allow-head?)]
[datum
(atomic-datum? #'datum)
(create-pat:datum (syntax->datum #'datum))]
[(~var . rest)
(disappeared! stx)
(parse-pat:var stx decls allow-head?)]
[(~datum . rest)
(disappeared! stx)
(syntax-case stx (~datum)
[(~datum d)
(create-pat:datum (syntax->datum #'d))]
[_ (wrong-syntax stx "bad ~~datum form")])]
[(~literal . rest)
(disappeared! stx)
(parse-pat:literal stx decls)]
[(~and . rest)
(disappeared! stx)
(parse-pat:and stx decls allow-head? allow-ghost?)]
[(~or . rest)
(disappeared! stx)
(parse-pat:or stx decls allow-head?)]
[(~not . rest)
(disappeared! stx)
(parse-pat:not stx decls)]
[(~rest . rest)
(disappeared! stx)
(parse-pat:rest stx decls)]
[(~describe . rest)
(disappeared! stx)
(parse-pat:describe stx decls allow-head?)]
[(~seq . rest)
(disappeared! stx)
(check-head!
(parse-hpat:seq stx #'rest decls))]
[(~optional . rest)
(disappeared! stx)
(check-head!
(parse-hpat:optional stx decls))]
[(~bind . rest)
(disappeared! stx)
(check-ghost!
(parse-pat:bind stx decls))]
[(~fail . rest)
(disappeared! stx)
(check-ghost!
(parse-pat:fail stx decls #f))]
[(~early-fail . rest)
(disappeared! stx)
(check-ghost!
(parse-pat:fail stx decls #t))]
[(~parse . rest)
(disappeared! stx)
(check-ghost!
(parse-pat:parse stx decls))]
[(head dots . tail)
(dots? #'dots)
(begin (disappeared! #'dots)
(parse-pat:dots stx #'head #'tail decls))]
[(head plus-dots . tail)
(plus-dots? #'plus-dots)
(begin (disappeared! #'plus-dots)
(parse-pat:plus-dots stx #'head #'tail decls))]
[(head . tail)
(let ([headp (parse-*-pattern #'head decls #t #t)]
[tailp (parse-single-pattern #'tail decls)])
;; Only make pat:head if head is complicated;
;; otherwise simple compound/pair
;; FIXME: Could also inline ~seq patterns from head...?
(cond [(ghost-pattern? headp)
(create-pat:ghost headp tailp)]
[(head-pattern? headp)
(create-pat:head headp tailp)]
[else
(create-pat:compound '#:pair (list headp tailp))]))]
[#(a ...)
(let ([lp (parse-single-pattern (syntax/loc stx (a ...)) decls)])
(create-pat:compound '#:vector (list lp)))]
[b
(box? (syntax-e #'b))
(let ([bp (parse-single-pattern (unbox (syntax-e #'b)) decls)])
(create-pat:compound '#:box (list bp)))]
[s
(and (struct? (syntax-e #'s)) (prefab-struct-key (syntax-e #'s)))
(let* ([s (syntax-e #'s)]
[key (prefab-struct-key s)]
[contents (struct->list s)])
(let ([lp (parse-single-pattern (datum->syntax #f contents #'s) decls)])
(create-pat:compound `(#:pstruct ,key) (list lp))))]))
;; parse-ellipsis-head-pattern : stx DeclEnv number -> (listof EllipsisHeadPattern)
(define (parse-ellipsis-head-pattern stx decls)
(syntax-case stx (~or ~between ~optional ~once)
[(~or . _)
(begin
(unless (stx-list? stx)
(wrong-syntax stx "expected sequence of patterns"))
(apply append
(for/list ([sub (cdr (stx->list stx))])
(parse-ellipsis-head-pattern sub decls))))]
[(~optional . _)
(disappeared! stx)
(list (parse-ehpat/optional stx decls))]
[(~once . _)
(disappeared! stx)
(list (parse-ehpat/once stx decls))]
[(~between . _)
(disappeared! stx)
(list (parse-ehpat/bounds stx decls))]
[_
(let ([head (parse-head-pattern stx decls)])
(list (make ehpat (map increase-depth (pattern-attrs head))
head
#f)))]))
;; ----
(define (parse-pat:id id decls allow-head?)
(define entry (declenv-lookup decls id))
(match entry
[(struct den:lit (internal literal input-phase lit-phase))
(create-pat:literal literal input-phase lit-phase)]
[(struct den:class (_n _c _a))
(error 'parse-pat:id
"(internal error) decls had leftover stxclass entry: ~s"
entry)]
[(struct den:parser (parser desc attrs splicing? commit?))
;; FIXME: why no allow-head? check???
(if splicing?
(begin
(unless allow-head?
(wrong-syntax id "splicing syntax class not allowed here"))
(parse-pat:id/h id parser null attrs commit?))
(parse-pat:id/s id parser null attrs commit?))]
[(struct den:delayed (parser desc class))
(let ([sc (get-stxclass class)])
(cond [(stxclass/s? sc)
(parse-pat:id/s id
parser
null
(stxclass-attrs sc)
(stxclass-commit? sc))]
[(stxclass/h? sc)
(unless allow-head?
(wrong-syntax id "splicing syntax class not allowed here"))
(parse-pat:id/h id
parser
null
(stxclass-attrs sc)
(stxclass-commit? sc))]))]
['#f
(when #t ;; FIXME: right place???
(unless (safe-name? id)
(wrong-syntax id "expected identifier not starting with ~~ character")))
(let-values ([(name sc) (split-id/get-stxclass id decls)])
(if sc
(parse-pat:var* id allow-head? name sc null)
(create-pat:var name #f null null #t)))]))
(define (parse-pat:var stx decls allow-head?)
(define name0
(syntax-case stx (~var)
[(~var name . _)
(unless (identifier? #'name)
(wrong-syntax #'name "expected identifier"))
#'name]
[_
(wrong-syntax stx "bad ~~var form")]))
(define-values (scname args pfx)
(syntax-case stx (~var)
[(~var _name)
(values #f null #f)]
[(~var _name sc/sc+args . rest)
(let-values ([(sc args)
(syntax-case #'sc/sc+args ()
[sc
(identifier? #'sc)
(values #'sc null)]
[(sc arg ...)
(identifier? #'sc)
(values #'sc (syntax->list #'(arg ...)))]
[_
(wrong-syntax stx "bad ~~var form")])])
(define chunks
(parse-keyword-options/eol #'rest var-pattern-directive-table
#:no-duplicates? #t
#:context stx))
(define sep
(options-select-value chunks '#:attr-name-separator #:default #f))
(values sc args (if sep (syntax-e sep) ".")))]
[_
(wrong-syntax stx "bad ~~var form")]))
(cond [(and (epsilon? name0) (not scname))
(wrong-syntax name0 "illegal pattern variable name")]
[(and (wildcard? name0) (not scname))
(create-pat:any)]
[scname
(let ([sc (get-stxclass/check-arg-count scname (length args))])
(parse-pat:var* stx allow-head? name0 sc args pfx))]
[else ;; Just proper name
(create-pat:var name0 #f null null #t)]))
(define (parse-pat:var* stx allow-head? name sc args [pfx "."])
(cond [(stxclass/s? sc)
(parse-pat:id/s name
(stxclass-parser-name sc)
args
(stxclass-attrs sc)
(stxclass-commit? sc)
pfx)]
[(stxclass/h? sc)
(unless allow-head?
(wrong-syntax stx "splicing syntax class not allowed here"))
(parse-pat:id/h name
(stxclass-parser-name sc)
args
(stxclass-attrs sc)
(stxclass-commit? sc)
pfx)]))
(define (parse-pat:id/s name parser args attrs commit? [pfx "."])
(define prefix (name->prefix name pfx))
(define bind (name->bind name))
(create-pat:var bind parser args (id-pattern-attrs attrs prefix) commit?))
(define (parse-pat:id/h name parser args attrs commit? [pfx "."])
(define prefix (name->prefix name pfx))
(define bind (name->bind name))
(create-hpat:var bind parser args (id-pattern-attrs attrs prefix) commit?))
(define (name->prefix id pfx)
(cond [(wildcard? id) #f]
[(epsilon? id) id]
[else (format-id id "~a~a" (syntax-e id) pfx)]))
(define (name->bind id)
(cond [(wildcard? id) #f]
[(epsilon? id) #f]
[else id]))
;; id-pattern-attrs : (listof SAttr)IdPrefix -> (listof IAttr)
(define (id-pattern-attrs sattrs prefix)
(if prefix
(for/list ([a sattrs])
(prefix-attr a prefix))
null))
;; prefix-attr : SAttr identifier -> IAttr
(define (prefix-attr a prefix)
(make attr (prefix-attr-name prefix (attr-name a))
(attr-depth a)
(attr-syntax? a)))
;; prefix-attr-name : id symbol -> id
(define (prefix-attr-name prefix name)
(format-id prefix "~a~a" (syntax-e prefix) name))
;; ----
(define (parse-pat:literal stx decls)
(syntax-case stx (~literal)
[(~literal lit . more)
(unless (identifier? #'lit)
(wrong-syntax #'lit "expected identifier"))
(let* ([chunks (parse-keyword-options/eol #'more phase-directive-table
#:no-duplicates? #t
#:context stx)]
[phase (options-select-value chunks '#:phase #:default #f)])
;; FIXME: Duplicates phase expr!
(create-pat:literal #'lit phase phase))]
[_
(wrong-syntax stx "bad ~~literal pattern")]))
(define (parse-pat:describe stx decls allow-head?)
(syntax-case stx ()
[(_ . rest)
(let-values ([(chunks rest)
(parse-keyword-options #'rest describe-option-table
#:no-duplicates? #t
#:context stx)])
(define transparent? (and (assq '#:transparent chunks) #t))
(syntax-case rest ()
[(description pattern)
(let ([p (parse-*-pattern #'pattern decls allow-head? #f)])
(if (head-pattern? p)
(create-hpat:describe #'description transparent? p)
(create-pat:describe #'description transparent? p)))]))]))
(define (split-prefix xs pred)
(let loop ([xs xs] [rprefix null])
(cond [(and (pair? xs) (pred (car xs)))
(loop (cdr xs) (cons (car xs) rprefix))]
[else
(values (reverse rprefix) xs)])))
(define (parse-pat:and stx decls allow-head? allow-ghost?)
;; allow-ghost? = allowed to *return* pure ghost pattern;
;; all ~and patterns are allowed to *contain* ghost patterns
(define patterns0 (parse-cdr-patterns stx decls allow-head? #t))
(define-values (ghosts patterns) (split-prefix patterns0 ghost-pattern?))
(cond [(null? patterns)
(cond [allow-ghost?
(create-ghost:and ghosts)]
[allow-head?
(wrong-syntax stx "expected at least one head pattern")]
[else
(wrong-syntax stx "expected at least one single-term pattern")])]
[else
(let ([p (parse-pat:and* stx patterns)])
(if (head-pattern? p)
(for/fold ([p p]) ([ghost (reverse ghosts)])
(create-hpat:ghost ghost p))
(for/fold ([p p]) ([ghost (reverse ghosts)])
(create-pat:ghost ghost p))))]))
(define (parse-pat:and* stx patterns)
;; patterns is non-empty (empty case handled above)
(cond [(null? (cdr patterns))
(car patterns)]
[(ormap head-pattern? patterns)
;; Check to make sure *all* are head patterns
(for ([pattern patterns]
[pattern-stx (stx->list (stx-cdr stx))])
(unless (or (ghost-pattern? pattern) (head-pattern? pattern))
(wrong-syntax
pattern-stx
"single-term pattern not allowed after head pattern")))
(let ([p0 (car patterns)]
[lps (map ghost/head-pattern->list-pattern (cdr patterns))])
(create-hpat:and p0 (create-pat:and lps)))]
[else
(create-pat:and
(for/list ([p patterns])
(if (ghost-pattern? p)
(ghost-pattern->single-pattern p)
p)))]))
(define (parse-pat:or stx decls allow-head?)
(define patterns (parse-cdr-patterns stx decls allow-head? #f))
(cond [(null? (cdr patterns))
(car patterns)]
[else
(cond [(ormap head-pattern? patterns)
(create-hpat:or patterns)]
[else
(create-pat:or patterns)])]))
(define (parse-pat:not stx decls)
(syntax-case stx (~not)
[(~not pattern)
(let ([p (parse-single-pattern #'pattern decls)])
(create-pat:not p))]
[_
(wrong-syntax stx "expected a single subpattern")]))
(define (parse-hpat:seq stx list-stx decls)
(define pattern (parse-single-pattern list-stx decls))
(check-list-pattern pattern stx)
(create-hpat:seq pattern))
(define (parse-cdr-patterns stx decls allow-head? allow-ghost?)
(unless (stx-list? stx)
(wrong-syntax stx "expected sequence of patterns"))
(let ([result
(for/list ([sub (cdr (stx->list stx))])
(parse-*-pattern sub decls allow-head? allow-ghost?))])
(when (null? result)
(wrong-syntax stx "expected at least one pattern"))
result))
(define (parse-pat:dots stx head tail decls)
(define headps (parse-ellipsis-head-pattern head decls))
(define tailp (parse-single-pattern tail decls))
(unless (pair? headps)
(wrong-syntax head "expected at least one pattern"))
(create-pat:dots headps tailp))
(define (parse-pat:plus-dots stx head tail decls)
(define headp (parse-head-pattern head decls))
(define tailp (parse-single-pattern tail decls))
(define head/rep
(make-ehpat (map increase-depth (pattern-attrs headp))
headp
(make-rep:bounds 1 +inf.0 #f #f #f)))
(create-pat:dots (list head/rep) tailp))
(define (parse-pat:bind stx decls)
(syntax-case stx ()
[(_ clause ...)
(let ([clauses (check-bind-clause-list #'(clause ...) stx)])
(make ghost:bind
(append-iattrs (side-clauses-attrss clauses))
clauses))]))
(define (parse-pat:fail stx decls early?)
(syntax-case stx ()
[(_ . rest)
(let-values ([(chunks rest)
(parse-keyword-options #'rest fail-directive-table
#:context stx
#:incompatible '((#:when #:unless))
#:no-duplicates? #t)])
(let ([condition
(if (null? chunks)
#'#t
(let ([chunk (car chunks)])
(if (eq? (car chunk) '#:when)
(caddr chunk)
#`(not #,(caddr chunk)))))])
(syntax-case rest ()
[(message)
(create-ghost:fail early? condition #'message)]
[()
(wrong-syntax stx "missing message expression")]
[_
(wrong-syntax stx "bad ~~fail pattern")])))]))
(define (parse-pat:parse stx decls)
(syntax-case stx (~parse)
[(~parse pattern expr)
(let ([p (parse-single-pattern #'pattern decls)])
(create-ghost:parse p #'expr))]
[_
(wrong-syntax stx "bad ~~parse pattern")]))
(define (parse-pat:rest stx decls)
(syntax-case stx ()
[(_ pattern)
(parse-single-pattern #'pattern decls)]))
(define (check-list-pattern pattern stx)
(match pattern
[(make pat:datum _base '())
#t]
[(make pat:head _base _head tail)
(check-list-pattern tail stx)]
[(make pat:ghost _base _ghost tail)
(check-list-pattern tail stx)]
[(make pat:dots _base _head tail)
(check-list-pattern tail stx)]
[(make pat:compound _base '#:pair (list _head tail))
(check-list-pattern tail stx)]
[_
(wrong-syntax stx "expected proper list pattern")]))
(define (parse-hpat:optional stx decls)
(define-values (head all-iattrs _name _tmm defaults)
(parse-optional-pattern stx decls h-optional-directive-table))
(make hpat:optional all-iattrs head defaults))
(define (parse-ehpat/optional stx decls)
(define-values (head all-iattrs name too-many-msg defaults)
(parse-optional-pattern stx decls eh-optional-directive-table))
(make ehpat all-iattrs head
(make rep:optional name too-many-msg defaults)))
(define (parse-optional-pattern stx decls optional-directive-table)
(syntax-case stx (~optional)
[(~optional p . options)
(let ([head (parse-head-pattern #'p decls)])
(define chunks
(parse-keyword-options/eol #'options optional-directive-table
#:no-duplicates? #t
#:context stx))
(let ([too-many-msg
(options-select-value chunks '#:too-many #:default #'#f)]
[name
(options-select-value chunks '#:name #:default #'#f)]
[defaults
(options-select-value chunks '#:defaults #:default '())])
(define pattern-iattrs (pattern-attrs head))
(define defaults-iattrs
(append-iattrs (side-clauses-attrss defaults)))
(define all-iattrs
(union-iattrs (list pattern-iattrs defaults-iattrs)))
(check-iattrs-subset defaults-iattrs pattern-iattrs stx)
(values head all-iattrs name too-many-msg defaults)))]))
(define (parse-ehpat/once stx decls)
(syntax-case stx (~once)
[(~once p . options)
(let ([head (parse-head-pattern #'p decls)])
(define chunks
(parse-keyword-options/eol #'options
(list (list '#:too-few check-expression)
(list '#:too-many check-expression)
(list '#:name check-expression))
#:context stx))
(let ([too-few-msg
(options-select-value chunks '#:too-few #:default #'#f)]
[too-many-msg
(options-select-value chunks '#:too-many #:default #'#f)]
[name
(options-select-value chunks '#:name #:default #'#f)])
(make ehpat (pattern-attrs head)
head
(make rep:once name too-few-msg too-many-msg))))]))
(define (parse-ehpat/bounds stx decls)
(syntax-case stx (~between)
[(~between p min max . options)
(let ([head (parse-head-pattern #'p decls)])
(define minN (syntax-e #'min))
(define maxN (syntax-e #'max))
(unless (exact-nonnegative-integer? minN)
(wrong-syntax #'min
"expected exact nonnegative integer"))
(unless (or (exact-nonnegative-integer? maxN) (equal? maxN +inf.0))
(wrong-syntax #'max
"expected exact nonnegative integer or +inf.0"))
(when (> minN maxN)
(wrong-syntax stx "minimum larger than maximum repetition constraint"))
(let ([chunks (parse-keyword-options/eol
#'options
(list (list '#:too-few check-expression)
(list '#:too-many check-expression)
(list '#:name check-expression))
#:context stx)])
(let ([too-few-msg
(options-select-value chunks '#:too-few #:default #'#f)]
[too-many-msg
(options-select-value chunks '#:too-many #:default #'#f)]
[name
(options-select-value chunks '#:name #:default #'#f)])
(make ehpat (map increase-depth (pattern-attrs head))
head
(make rep:bounds #'min #'max
name too-few-msg too-many-msg)))))]))
;; -----
;; parse-pattern-directives : stxs(PatternDirective) <kw-args>
;; -> stx DeclEnv (listof stx) (listof SideClause)
(define (parse-pattern-directives stx
#:allow-declare? allow-declare?
#:decls decls
#:context [ctx (current-syntax-context)])
(parameterize ((current-syntax-context ctx))
(define-values (chunks rest)
(parse-keyword-options stx pattern-directive-table #:context ctx))
(define-values (decls2 chunks2)
(if allow-declare?
(grab-decls chunks decls)
(values decls chunks)))
(define sides
;; NOTE: use *original* decls
;; because decls2 has #:declares for *above* pattern
(parse-pattern-sides chunks2 decls))
(define-values (decls3 defs)
(decls-create-defs decls2))
(values rest decls3 defs (parse-pattern-sides chunks2 decls))))
;; parse-pattern-sides : (listof chunk) DeclEnv
;; -> (listof SideClause/c)
;; Invariant: decls contains only literals bindings
(define (parse-pattern-sides chunks decls)
(match chunks
[(cons (list '#:declare declare-stx _ _) rest)
(wrong-syntax declare-stx
"#:declare can only follow pattern or #:with clause")]
[(cons (list '#:fail-when fw-stx when-condition expr) rest)
(cons (make clause:fail when-condition expr)
(parse-pattern-sides rest decls))]
[(cons (list '#:fail-unless fu-stx unless-condition expr) rest)
(cons (make clause:fail #`(not #,unless-condition) expr)
(parse-pattern-sides rest decls))]
[(cons (list '#:when w-stx unless-condition) rest)
;; Bleh: when is basically fail-unless without the msg argument
(cons (make clause:fail #`(not #,unless-condition) #'#f)
(parse-pattern-sides rest decls))]
[(cons (list '#:with with-stx pattern expr) rest)
(let-values ([(decls2 rest) (grab-decls rest decls)])
(let-values ([(decls2a defs) (decls-create-defs decls2)])
(cons (make clause:with (parse-whole-pattern pattern decls2a) expr defs)
(parse-pattern-sides rest decls))))]
[(cons (list '#:attr attr-stx a expr) rest)
(cons (make clause:attr a expr)
(parse-pattern-sides rest decls))]
['()
'()]))
;; grab-decls : (listof chunk) DeclEnv
;; -> (values DeclEnv (listof chunk))
(define (grab-decls chunks decls0)
(define (add-decl stx decls)
(syntax-case stx ()
[(#:declare name sc)
(identifier? #'sc)
(add-decl* decls #'name #'sc null)]
[(#:declare name (sc expr ...))
(identifier? #'sc)
(add-decl* decls #'name #'sc (syntax->list #'(expr ...)))]
[(#:declare name bad-sc)
(wrong-syntax #'bad-sc
"expected syntax class name (possibly with parameters)")]))
(define (add-decl* decls id sc-name args)
(declenv-put-stxclass decls id sc-name args))
(define (loop chunks decls)
(match chunks
[(cons (cons '#:declare decl-stx) rest)
(loop rest (add-decl decl-stx decls))]
[_ (values decls chunks)]))
(loop chunks decls0))
;; ----
;; Keyword Options & Checkers
;; check-attr-arity-list : stx stx -> (listof SAttr)
(define (check-attr-arity-list stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected list of attribute declarations" ctx stx))
(let ([iattrs (for/list ([x (stx->list stx)]) (check-attr-arity x ctx))])
(iattrs->sattrs (append-iattrs (map list iattrs)))))
;; check-attr-arity : stx stx -> IAttr
(define (check-attr-arity stx ctx)
(syntax-case stx ()
[attr
(identifier? #'attr)
(make-attr #'attr 0 #f)]
[(attr depth)
(begin (unless (identifier? #'attr)
(raise-syntax-error #f "expected attribute name" ctx #'attr))
(unless (exact-nonnegative-integer? (syntax-e #'depth))
(raise-syntax-error #f "expected depth (nonnegative integer)" ctx #'depth))
(make-attr #'attr (syntax-e #'depth) #f))]
[_
(raise-syntax-error #f "expected attribute name with optional depth declaration" ctx stx)]))
;; check-literals-list : stx stx -> (listof (list id id ct-phase ct-phase))
;; - txlifts defs of phase expressions
;; - txlifts checks that literals are bound
(define (check-literals-list stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected literals list" ctx stx))
(let ([lits (for/list ([x (stx->list stx)]) (check-literal-entry x ctx))])
(let ([dup (check-duplicate-identifier (map car lits))])
(when dup (raise-syntax-error #f "duplicate literal identifier" ctx dup)))
lits))
;; check-literal-entry : stx stx -> (list id id ct-phase ct-phase)
(define (check-literal-entry stx ctx)
(define (go internal external phase)
(txlift #`(check-literal (quote-syntax #,external)
#,phase (quote-syntax #,ctx)))
(list internal external phase phase))
(syntax-case stx ()
[(internal external #:phase phase)
(and (identifier? #'internal) (identifier? #'external))
(go #'internal #'external (txlift #'phase))]
[(internal external)
(and (identifier? #'internal) (identifier? #'external))
(go #'internal #'external #'(syntax-local-phase-level))]
[id
(identifier? #'id)
(go #'id #'id #'(syntax-local-phase-level))]
[_
(raise-syntax-error #f "expected literal entry"
ctx stx)]))
;; Literal sets - Definition
;; check-literals-list/litset : stx stx -> (listof (list id id))
(define (check-literals-list/litset stx ctx)
(let ([lits (for/list ([x (stx->list stx)])
(check-literal-entry/litset x ctx))])
(let ([dup (check-duplicate-identifier (map car lits))])
(when dup (raise-syntax-error #f "duplicate literal identifier" ctx dup)))
lits))
;; check-literal-entry/litset : stx stx -> (list id id)
(define (check-literal-entry/litset stx ctx)
(syntax-case stx ()
[(internal external)
(and (identifier? #'internal) (identifier? #'external))
(list #'internal #'external)]
[id
(identifier? #'id)
(list #'id #'id)]
[_
(raise-syntax-error #f "expected literal entry"
ctx stx)]))
;; Literal sets - Import
;; check-literal-sets-list : stx stx -> (listof (listof (list id id ct-phase^2)))
(define (check-literal-sets-list stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected literal-set list" ctx stx))
(for/list ([x (stx->list stx)])
(check-literal-set-entry x ctx)))
;; check-literal-set-entry : stx stx -> (listof (list id id ct-phase^2))
(define (check-literal-set-entry stx ctx)
(define (elaborate litset-id lctx phase)
(let ([litset (syntax-local-value/catch litset-id literalset?)])
(unless litset
(raise-syntax-error #f "expected identifier defined as a literal-set"
ctx litset-id))
(elaborate2 litset lctx phase)))
(define (elaborate2 litset lctx phase)
(for/list ([entry (literalset-literals litset)])
(list (datum->syntax lctx (car entry) stx)
(cadr entry)
phase
(literalset-phase litset))))
(syntax-case stx ()
[(litset . more)
(and (identifier? #'litset))
(let* ([chunks (parse-keyword-options/eol #'more litset-directive-table
#:no-duplicates? #t
#:context ctx)]
[lctx (options-select-value chunks '#:at #:default #'litset)]
[phase (options-select-value chunks '#:phase
#:default #'(syntax-local-phase-level))])
(elaborate #'litset lctx (txlift phase)))]
[litset
(identifier? #'litset)
(elaborate #'litset #'litset #'(syntax-local-phase-level))]
[_
(raise-syntax-error #f "expected literal-set entry" ctx stx)]))
;; Conventions
;; returns (listof (cons Conventions (listof syntax)))
(define (check-conventions-list stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected conventions list" ctx stx))
(for/list ([x (stx->list stx)])
(check-conventions x ctx)))
;; returns (cons Conventions (listof syntax))
(define (check-conventions stx ctx)
(define (elaborate conventions-id args)
(let ([cs (syntax-local-value/catch conventions-id conventions?)])
(unless cs
(raise-syntax-error #f "expected identifier defined as a conventions"
ctx conventions-id))
(cons cs args)))
(syntax-case stx ()
[(conventions arg ...)
(identifier? #'conventions)
(elaborate #'conventions (syntax->list #'(arg ...)))]
[conventions
(identifier? #'conventions)
(elaborate #'conventions null)]
[_
(raise-syntax-error "expected conventions entry" ctx stx)]))
;; returns (listof (list regexp DeclEntry))
(define (check-conventions-rules stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected convention rule list" ctx stx))
(for/list ([x (stx->list stx)])
(check-conventions-rule x ctx)))
;; returns (list regexp DeclEntry)
(define (check-conventions-rule stx ctx)
(define (check-conventions-pattern x blame)
(cond [(symbol? x)
(regexp (string-append "^" (regexp-quote (symbol->string x)) "$"))]
[(regexp? x) x]
[else
(raise-syntax-error #f "expected identifier convention pattern"
ctx blame)]))
(define (check-sc-expr x rx)
(syntax-case x ()
[sc
(identifier? #'sc)
(make den:class rx #'sc null)]
[(sc arg ...)
(identifier? #'sc)
(make den:class rx #'sc (syntax->list #'(arg ...)))]
[_ (raise-syntax-error #f "expected syntax class use" ctx x)]))
(syntax-case stx ()
[(rx sc)
(let ([name-pattern (check-conventions-pattern (syntax-e #'rx) #'rx)])
(list name-pattern
(check-sc-expr #'sc name-pattern)))]))
;; bind clauses
(define (check-bind-clause-list stx ctx)
(unless (stx-list? stx)
(raise-syntax-error #f "expected sequence of bind clauses" ctx stx))
(for/list ([clause (stx->list stx)])
(check-bind-clause clause ctx)))
(define (check-bind-clause clause ctx)
(syntax-case clause ()
[(attr-decl expr)
(make clause:attr (check-attr-arity #'attr-decl ctx) #'expr)]
[_ (raise-syntax-error #f "expected bind clause" ctx clause)]))
;; Directive tables
;; common-parse-directive-table
(define common-parse-directive-table
(list (list '#:literals check-literals-list)
(list '#:literal-sets check-literal-sets-list)
(list '#:conventions check-conventions-list)
(list '#:local-conventions check-conventions-rules)))
;; parse-directive-table
(define parse-directive-table
(list* (list '#:context check-expression)
common-parse-directive-table))
;; rhs-directive-table
(define rhs-directive-table
(list* (list '#:description check-expression)
(list '#:transparent)
(list '#:opaque)
(list '#:attributes check-attr-arity-list)
(list '#:auto-nested-attributes)
(list '#:commit? check-stx-boolean)
common-parse-directive-table))
;; pattern-directive-table
(define pattern-directive-table
(list (list '#:declare check-identifier check-expression)
(list '#:fail-when check-expression check-expression)
(list '#:fail-unless check-expression check-expression)
(list '#:when check-expression)
(list '#:with check-expression check-expression)
(list '#:attr check-attr-arity check-expression)))
;; fail-directive-table
(define fail-directive-table
(list (list '#:when check-expression)
(list '#:unless check-expression)))
;; describe-option-table
(define describe-option-table
(list (list '#:transparent)))
;; eh-optional-directive-table
(define eh-optional-directive-table
(list (list '#:too-many check-expression)
(list '#:name check-expression)
(list '#:defaults check-bind-clause-list)))
;; h-optional-directive-table
(define h-optional-directive-table
(list (list '#:defaults check-bind-clause-list)))
;; phase-directive-table
(define phase-directive-table
(list (list '#:phase check-expression)))
;; litset-directive-table
(define litset-directive-table
(cons (list '#:at check-identifier)
phase-directive-table))
;; var-pattern-directive-table
(define var-pattern-directive-table
(list (list '#:attr-name-separator check-stx-string)))