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

1623 lines
61 KiB
Racket

#lang racket/base
(require (for-template racket/base
racket/stxparam
"keywords.rkt"
"runtime.rkt")
racket/contract/base
"minimatch.rkt"
syntax/id-table
syntax/stx
syntax/keyword
racket/syntax
unstable/struct
"txlift.rkt"
"rep-data.rkt"
"kws.rkt")
;; 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?)]
[optimize-rhs
(-> rhs? any/c
(or/c #f (list/c rhs? syntax?)))]
[parse-pattern+sides
(-> syntax? syntax?
#:splicing? boolean?
#:decls DeclEnv/c
#:context syntax?
any)]
[parse*-ellipsis-head-pattern
(-> syntax? DeclEnv/c boolean?
#:context syntax?
any)]
[parse-directive-table any/c]
[get-decls+defs
(-> list? boolean? #:context (or/c false/c syntax?)
(values DeclEnv/c (listof syntax?)))]
[create-aux-def
(-> DeclEntry/c
(values DeclEntry/c (listof syntax?)))]
[parse-argu
(-> (listof syntax?)
#:context syntax?
arguments?)]
[parse-kw-formals
(-> syntax?
#:context syntax?
arity?)]
[check-literals-list/litset
(-> syntax? syntax?
(listof (list/c identifier? identifier?)))]
[check-conventions-rules
(-> syntax? syntax?
(listof (list/c regexp? any/c)))]
[check-attr-arity-list
(-> syntax? syntax?
(listof sattr?))])
;; ----
(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 ~parse)
(quote-syntax ~do)
(quote-syntax ...+)
(quote-syntax ~delimit-cut)
(quote-syntax ~commit)
(quote-syntax ~reflect)
(quote-syntax ~splicing-reflect)
(quote-syntax ~eh-var)
(quote-syntax ~peek)
(quote-syntax ~peek-not)))
(define (reserved? stx)
(and (identifier? stx)
(for/or ([kw (in-list keywords)])
(free-identifier=? stx kw))))
(define (safe-name? stx)
(and (identifier? stx)
(not (regexp-match? #rx"^~" (symbol->string (syntax-e stx))))))
;; cut-allowed? : (paramter/c boolean?)
;; Used to detect ~cut within ~not pattern.
;; (Also #:no-delimit-cut stxclass within ~not)
(define cut-allowed? (make-parameter #t))
;; ---
(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? colon-notation?
decls defs options)
(parse-rhs/part1 stx splicing? (and expected-attrs #t)))
(define variants
(parameterize ((stxclass-lookup-config
(cond [expected-attrs 'yes]
[auto-nested? 'try]
[else 'no]))
(stxclass-colon-notation? colon-notation?))
(parse-variants rest decls splicing? expected-attrs)))
(let ([sattrs
(or attributes
(intersect-sattrss (map variant-attrs variants)))])
(make rhs stx sattrs transp? description variants
(append (get-txlifts-as-definitions) defs)
options #f))))))
(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)
(#:commit #:no-delimit-cut))
#: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 colon-notation? (not (assq '#:disable-colon-notation chunks)))
(define commit?
(and (assq '#:commit chunks) #t))
(define delimit-cut?
(not (assq '#:no-delimit-cut chunks)))
(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? colon-notation?
decls defs (make options commit? delimit-cut?)))
;; ----
#|
A syntax class is integrable if
- only positional params without defaults
- no attributes
- description is a string constant
- one variant: (~fail #:when/unless cond) ... no message
- and thus no txlifted definitions, no convention definitions, etc
- don't care about commit?, delimit-cut?, transparent?
because other restrictions make them irrelevant
|#
;; optimize-rhs : RHS stxlist -> (list RHS stx)/#f
;; Returns #f to indicate cannot integrate.
(define (optimize-rhs rhs0 params)
(define (check-stx-string x)
(syntax-case x (quote)
[(quote str) (string? (syntax-e #'str)) #'str]
[_ #f]))
(define (stx-false? x)
(syntax-case x (quote)
[(quote #f) #t]
[_ #f]))
(match rhs0
[(rhs _o '() _trans? (? check-stx-string description) (list variant0) '() _opts '#f)
(match variant0
[(variant _o '() pattern0 '())
(match pattern0
[(pat:action '() (action:fail '() cond-stx msg-stx) (pat:any '()))
(cond [(stx-false? msg-stx)
;; Yes!
(with-syntax ([(predicate) (generate-temporaries #'(predicate))]
[(param ...) params]
[fail-condition cond-stx])
(let* ([predicate-def
#'(define (predicate x param ...)
(syntax-parameterize ((this-syntax
(make-rename-transformer
(quote-syntax x))))
(#%expression (not fail-condition))))]
[integrate* (make integrate #'predicate
(check-stx-string description))]
[pattern*
(create-pat:action
(create-action:fail #'(not (predicate this-syntax param ...)) #'#f)
(create-pat:any))]
[variant*
(variant _o '() pattern* '())])
(list
(make rhs _o '() _trans? description (list variant*) '() _opts integrate*)
predicate-def)))]
[else #f])]
[_ #f])]
[_ #f])]
[_ #f]))
;; ----
(define (parse-variants rest decls splicing? expected-attrs)
(define (gather-variants stx)
(syntax-case stx (pattern)
[((pattern . _) . rest)
(begin (disappeared! (stx-car stx))
(cons (parse-variant (stx-car stx) splicing? decls expected-attrs)
(gather-variants #'rest)))]
[(bad-variant . rest)
(wrong-syntax #'bad-variant "expected syntax-class variant")]
[()
null]))
(gather-variants 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 (in-list convs)])
(let* ([c (car conv-entry)]
[argu (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 argu)
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 Argument -> syntax
(define (make-conventions-def dens get-parsers-id argu)
(with-syntax ([(parser ...) (map den:delayed-parser dens)]
[get-parsers get-parsers-id]
[argu argu])
#'(define-values (parser ...)
(apply values (app-argu get-parsers argu)))))
;; 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:magic-class (name class argu))
(values entry null)]
[(struct den:class (name class argu))
;; FIXME: integrable syntax classes?
(cond [(identifier? name)
(let* ([pos-count (length (arguments-pargs argu))]
[kws (arguments-kws argu)]
[sc (get-stxclass/check-arity class class pos-count kws)])
(with-syntax ([sc-parser (stxclass-parser sc)])
(with-syntax ([parser (generate-temporary class)])
(values (make den:parser #'parser
(stxclass-attrs sc) (stxclass/h? sc)
(stxclass-commit? sc) (stxclass-delimit-cut? sc))
(list #`(define-values (parser)
(curried-stxclass-parser #,class #,argu)))))))]
[(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 class)
(list #`(define-values (parser)
(curried-stxclass-parser #,class #,argu)))))])]
[(struct den:parser (_p _a _sp _c _dc?))
(values entry null)]
[(struct den:delayed (_p _c))
(values entry null)]))
(define (append-lits+litsets lits litsets)
(define seen (make-bound-id-table lits))
(for ([litset (in-list litsets)])
(for ([lit (in-list 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 pattern defs)
(parse-pattern+sides #'p #'rest
#:splicing? splicing?
#:decls decls0
#:context stx)])
(disappeared! stx)
(unless (stx-null? rest)
(wrong-syntax (if (pair? rest) (car rest) rest)
"unexpected terms after pattern directives"))
(let* ([attrs (pattern-attrs pattern)]
[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 defs)))]))
;; parse-pattern+sides : stx stx <options> -> (values stx Pattern (listof stx))
;; Parses pattern, side clauses; desugars side clauses & merges with pattern
(define (parse-pattern+sides p-stx s-stx
#:splicing? splicing?
#:decls decls0
#:context ctx)
(let-values ([(rest decls defs sides)
(parse-pattern-directives s-stx
#:allow-declare? #t
#:decls decls0
#:context ctx)])
(let* ([pattern0 (parse-whole-pattern p-stx decls splicing? #:context ctx)]
[pattern (combine-pattern+sides pattern0 sides splicing?)])
(values rest pattern defs))))
(define (side-clauses-attrss clauses)
(for/list ([c (in-list 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))
;; combine-pattern+sides : Pattern (listof SideClause) -> Pattern
(define (combine-pattern+sides pattern sides splicing?)
(define actions-pattern
(create-action:and
(for/list ([side (in-list sides)])
(match side
[(make clause:fail condition message)
(create-action:post
(create-action:fail condition message))]
[(make clause:with wpat expr defs)
(let ([ap (create-action:post
(create-action:parse wpat expr))])
(if (pair? defs)
(create-action:and (list (create-action:do defs) ap))
ap))]
[(make clause:attr attr expr)
(create-action:bind (list side))]
[(make clause:do stmts)
(create-action:do stmts)]))))
(define dummy-pattern
(and (pair? sides)
(create-pat:action actions-pattern (create-pat:any))))
(if dummy-pattern
(if splicing?
(create-hpat:and pattern dummy-pattern)
(create-pat:and (list pattern dummy-pattern)))
pattern))
;; ----
;; parse-single-pattern : stx DeclEnv -> SinglePattern
(define (parse-single-pattern stx decls)
(parse-*-pattern stx decls #f #f))
;; 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-action?)
(define (check-head! x)
(unless allow-head?
(wrong-syntax stx "head pattern not allowed here"))
x)
(define (check-action! x)
;; Coerce to S-pattern IF only S-patterns allowed
(cond [allow-action? x]
[(not allow-head?) (action-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 ~parse ~do
~post ~peek ~peek-not ~delimit-cut ~commit ~reflect
~splicing-reflect)
[wildcard
(wildcard? #'wildcard)
(begin (disappeared! stx)
(create-pat:any))]
[~!
(disappeared! stx)
(begin
(unless (cut-allowed?)
(wrong-syntax stx
"cut (~~!) not allowed within ~~not pattern"))
(check-action!
(create-action: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-action?)]
[(~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?)]
[(~delimit-cut . rest)
(disappeared! stx)
(parse-pat:delimit stx decls allow-head?)]
[(~commit . rest)
(disappeared! stx)
(parse-pat:commit stx decls allow-head?)]
[(~reflect . rest)
(disappeared! stx)
(parse-pat:reflect stx decls #f)]
[(~seq . rest)
(disappeared! stx)
(check-head!
(parse-hpat:seq stx #'rest decls))]
[(~optional . rest)
(disappeared! stx)
(check-head!
(parse-hpat:optional stx decls))]
[(~splicing-reflect . rest)
(disappeared! stx)
(check-head!
(parse-pat:reflect stx decls #t))]
[(~bind . rest)
(disappeared! stx)
(check-action!
(parse-pat:bind stx decls))]
[(~fail . rest)
(disappeared! stx)
(check-action!
(parse-pat:fail stx decls))]
[(~post . rest)
(disappeared! stx)
(parse-pat:post stx decls allow-head? allow-action?)]
[(~peek . rest)
(disappeared! stx)
(check-head!
(parse-pat:peek stx decls))]
[(~peek-not . rest)
(disappeared! stx)
(check-head!
(parse-pat:peek-not stx decls))]
[(~parse . rest)
(disappeared! stx)
(check-action!
(parse-pat:parse stx decls))]
[(~do . rest)
(disappeared! stx)
(check-action!
(parse-pat:do 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)])
(cond [(action-pattern? headp)
(create-pat:action headp tailp)]
[(head-pattern? headp)
(create-pat:head headp tailp)]
[else
(create-pat:pair headp tailp)]))]
[#(a ...)
(let ([lp (parse-single-pattern (syntax/loc stx (a ...)) decls)])
(create-pat:vector lp))]
[b
(box? (syntax-e #'b))
(let ([bp (parse-single-pattern (unbox (syntax-e #'b)) decls)])
(create-pat:box 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:pstruct key lp)))]))
;; parse-ellipsis-head-pattern : stx DeclEnv -> (listof EllipsisHeadPattern)
(define (parse-ellipsis-head-pattern stx decls)
(for/list ([ehpat+hstx (in-list (parse*-ellipsis-head-pattern stx decls #t))])
(car ehpat+hstx)))
;; parse*-ellipsis-head-pattern : stx DeclEnv bool
;; -> (listof (list EllipsisHeadPattern stx/eh-alternative))
(define (parse*-ellipsis-head-pattern stx decls allow-or?
#:context [ctx (current-syntax-context)])
(syntax-case stx (~eh-var ~or ~between ~optional ~once)
[(~eh-var name eh-alt-set-id)
(let ()
(define prefix (name->prefix #'name "."))
(define eh-alt-set (get-eh-alternative-set #'eh-alt-set-id))
(for/list ([alt (in-list (eh-alternative-set-alts eh-alt-set))])
(let* ([iattrs (id-pattern-attrs (eh-alternative-attrs alt) prefix)]
[attr-count (length iattrs)])
(list (make ehpat (repc-adjust-attrs iattrs (eh-alternative-repc alt))
(create-hpat:var #f (eh-alternative-parser alt) no-arguments iattrs attr-count #f)
(eh-alternative-repc alt))
(replace-eh-alternative-attrs
alt (iattrs->sattrs iattrs))))))]
[(~or . _)
allow-or?
(begin
(unless (stx-list? stx)
(wrong-syntax stx "expected sequence of patterns"))
(apply append
(for/list ([sub (in-list (cdr (stx->list stx)))])
(parse*-ellipsis-head-pattern sub decls allow-or?))))]
[(~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 (list (make ehpat (map increase-depth (pattern-attrs head))
head
#f)
stx)))]))
(define (repc-adjust-attrs iattrs repc)
(cond [(or (rep:once? repc) (rep:optional? repc))
iattrs]
[(or (rep:bounds? repc) (eq? #f repc))
(map increase-depth iattrs)]
[else
(error 'repc-adjust-attrs "INTERNAL ERROR: unexpected: ~e" repc)]))
(define (replace-eh-alternative-attrs alt sattrs)
(match alt
[(eh-alternative repc _attrs parser)
(eh-alternative repc sattrs parser)]))
;; ----
(define (check-no-delimit-cut-in-not id delimit-cut?)
(unless (or delimit-cut? (cut-allowed?))
(wrong-syntax id
(string-append "syntax class with #:no-delimit-cut option "
"not allowed within ~~not pattern"))))
(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:magic-class (name class argu))
(let* ([pos-count (length (arguments-pargs argu))]
[kws (arguments-kws argu)]
[sc (get-stxclass/check-arity class class pos-count kws)]
[splicing? (stxclass-splicing? sc)]
[attrs (stxclass-attrs sc)]
[parser (stxclass-parser sc)]
[commit? (stxclass-commit? sc)]
[delimit-cut? (stxclass-delimit-cut? sc)])
(check-no-delimit-cut-in-not id delimit-cut?)
(if splicing?
(begin
(unless allow-head?
(wrong-syntax id "splicing syntax class not allowed here"))
(parse-pat:id/h id parser argu attrs commit?))
(parse-pat:id/s id parser argu attrs commit?)))]
[(struct den:class (_n _c _a))
(error 'parse-pat:id
"(internal error) decls had leftover stxclass entry: ~s"
entry)]
[(struct den:parser (parser attrs splicing? commit? delimit-cut?))
(begin
(check-no-delimit-cut-in-not id delimit-cut?)
(if splicing?
(begin
(unless allow-head?
(wrong-syntax id "splicing syntax class not allowed here"))
(parse-pat:id/h id parser no-arguments attrs commit?))
(parse-pat:id/s id parser no-arguments attrs commit?)))]
[(struct den:delayed (parser class))
(let ([sc (get-stxclass class)])
(check-no-delimit-cut-in-not id (stxclass-delimit-cut? sc))
(cond [(stxclass/s? sc)
(parse-pat:id/s id
parser
no-arguments
(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
no-arguments
(stxclass-attrs sc)
(stxclass-commit? sc))]))]
['#f
(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 no-arguments)
(create-pat:var name #f no-arguments null #f #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 argu pfx)
(syntax-case stx (~var)
[(~var _name)
(values #f null #f)]
[(~var _name sc/sc+args . rest)
(let-values ([(sc argu)
(syntax-case #'sc/sc+args ()
[sc
(identifier? #'sc)
(values #'sc no-arguments)]
[(sc arg ...)
(identifier? #'sc)
(values #'sc (parse-argu (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 argu (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-arity scname stx
(length (arguments-pargs argu))
(arguments-kws argu))])
(parse-pat:var* stx allow-head? name0 sc argu pfx))]
[else ;; Just proper name
(create-pat:var name0 #f (arguments null null null) null #f #t)]))
(define (parse-pat:var* stx allow-head? name sc argu [pfx "."])
(check-no-delimit-cut-in-not stx (stxclass-delimit-cut? sc))
(cond [(stxclass/s? sc)
(if (and (stxclass-integrate sc) (null? (arguments-kws argu)))
(parse-pat:id/s/integrate name (stxclass-integrate sc) argu)
(parse-pat:id/s name
(stxclass-parser sc)
argu
(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 sc)
argu
(stxclass-attrs sc)
(stxclass-commit? sc)
pfx)]))
(define (parse-pat:id/s name parser argu attrs commit? [pfx "."])
(define prefix (name->prefix name pfx))
(define bind (name->bind name))
(create-pat:var bind parser argu (id-pattern-attrs attrs prefix) (length attrs) commit?))
(define (parse-pat:id/s/integrate name integrate argu)
(define bind (name->bind name))
(create-pat:integrated bind argu
(integrate-predicate integrate)
(integrate-description integrate)))
(define (parse-pat:id/h name parser argu attrs commit? [pfx "."])
(define prefix (name->prefix name pfx))
(define bind (name->bind name))
(create-hpat:var bind parser argu (id-pattern-attrs attrs prefix) (length attrs) 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 (in-list 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:reflect stx decls splicing?)
(syntax-case stx ()
[(_ name (obj arg ...) . maybe-signature)
(let ()
(unless (identifier? #'var)
(raise-syntax-error #f "expected identifier" stx #'name))
(define attr-decls
(syntax-case #'maybe-signature ()
[(#:attributes attr-decls)
(check-attr-arity-list #'attr-decls stx)]
[() null]
[_ (raise-syntax-error #f "bad syntax" stx)]))
(define prefix (name->prefix #'name "."))
(define bind (name->bind #'name))
(define ctor (if splicing? create-hpat:reflect create-pat:reflect))
(ctor #'obj (parse-argu (syntax->list #'(arg ...))) attr-decls bind
(id-pattern-attrs attr-decls prefix)))]))
;; ---
(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 #'(syntax-local-phase-level))])
;; 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? (not (assq '#:opaque chunks)))
(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 (parse-pat:delimit stx decls allow-head?)
(syntax-case stx ()
[(_ pattern)
(let ([p (parameterize ((cut-allowed? #t))
(parse-*-pattern #'pattern decls allow-head? #f))])
(if (head-pattern? p)
(create-hpat:delimit p)
(create-pat:delimit p)))]))
(define (parse-pat:commit stx decls allow-head?)
(syntax-case stx ()
[(_ pattern)
(let ([p (parameterize ((cut-allowed? #t))
(parse-*-pattern #'pattern decls allow-head? #f))])
(if (head-pattern? p)
(create-hpat:commit p)
(create-pat:commit 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-action?)
;; allow-action? = allowed to *return* pure action pattern;
;; all ~and patterns are allowed to *contain* action patterns
(define patterns0 (parse-cdr-patterns stx decls allow-head? #t))
(define-values (actions patterns) (split-prefix patterns0 action-pattern?))
(cond [(null? patterns)
(cond [allow-action?
(create-action:and actions)]
[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]) ([action (in-list (reverse actions))])
(create-hpat:action action p))
(for/fold ([p p]) ([action (in-list (reverse actions))])
(create-pat:action action 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 (in-list patterns)]
[pattern-stx (in-list (stx->list (stx-cdr stx)))])
(unless (or (action-pattern? pattern) (head-pattern? pattern))
(wrong-syntax
pattern-stx
"single-term pattern not allowed after head pattern")))
(let ([p0 (car patterns)]
[lps (map action/head-pattern->list-pattern (cdr patterns))])
(create-hpat:and p0 (create-pat:and lps)))]
[else
(create-pat:and
(for/list ([p (in-list patterns)])
(if (action-pattern? p)
(action-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 (parameterize ((cut-allowed? #f))
(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-action?)
(unless (stx-list? stx)
(wrong-syntax stx "expected sequence of patterns"))
(let ([result
(for/list ([sub (in-list (cdr (stx->list stx)))])
(parse-*-pattern sub decls allow-head? allow-action?))])
(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 action:bind
(append-iattrs (side-clauses-attrss clauses))
clauses))]))
(define (parse-pat:fail stx decls)
(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-action:fail condition #'message)]
[()
(create-action:fail condition #''#f)]
[_
(wrong-syntax stx "bad ~~fail pattern")])))]))
(define (parse-pat:post stx decls allow-head? allow-action?)
(syntax-case stx ()
[(_ pattern)
(let ([p (parse-*-pattern #'pattern decls allow-head? allow-action?)])
(cond [(action-pattern? p)
(cond [allow-action? (create-action:post p)]
[(not allow-head?) (create-pat:post (action-pattern->single-pattern p))]
[else (wrong-syntax stx "action pattern not allowed here")])]
[(head-pattern? p)
(cond [allow-head? (create-hpat:post p)]
[else (wrong-syntax stx "head pattern now allowed here")])]
[else
(create-pat:post p)]))]))
(define (parse-pat:peek stx decls)
(syntax-case stx (~peek)
[(~peek pattern)
(let ([p (parse-head-pattern #'pattern decls)])
(create-hpat:peek p))]))
(define (parse-pat:peek-not stx decls)
(syntax-case stx (~peek-not)
[(~peek-not pattern)
(let ([p (parse-head-pattern #'pattern decls)])
(create-hpat:peek-not p))]))
(define (parse-pat:parse stx decls)
(syntax-case stx (~parse)
[(~parse pattern expr)
(let ([p (parse-single-pattern #'pattern decls)])
(create-action:parse p #'expr))]
[_
(wrong-syntax stx "bad ~~parse pattern")]))
(define (parse-pat:do stx decls)
(syntax-case stx (~do)
[(~do stmt ...)
(create-action:do (syntax->list #'(stmt ...)))]
[_
(wrong-syntax stx "bad ~~do 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:action _base _action tail)
(check-list-pattern tail stx)]
[(make pat:dots _base _head tail)
(check-list-pattern tail stx)]
[(make pat:pair _base _head tail)
(check-list-pattern tail stx)]
[_
(wrong-syntax stx "expected proper list pattern")]))
(define (parse-hpat:optional stx decls)
(define-values (head-stx head iattrs _name _tmm defaults)
(parse*-optional-pattern stx decls h-optional-directive-table))
(make hpat:optional iattrs head defaults))
;; parse*-optional-pattern : stx DeclEnv table
;; -> (values
(define (parse*-optional-pattern stx decls optional-directive-table)
(syntax-case stx (~optional)
[(~optional p . options)
(let* ([head (parse-head-pattern #'p decls)]
[chunks
(parse-keyword-options/eol #'options optional-directive-table
#:no-duplicates? #t
#:context stx)]
[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 '())]
[pattern-iattrs (pattern-attrs head)]
[defaults-iattrs
(append-iattrs (side-clauses-attrss defaults))]
[all-iattrs
(union-iattrs (list pattern-iattrs defaults-iattrs))])
(check-iattrs-subset defaults-iattrs pattern-iattrs stx)
(values #'p head all-iattrs name too-many-msg defaults))]))
;; -- EH patterns
;; Only parse the rep-constraint part; don't parse the head pattern within.
;; (To support eh-alternative-sets.)
;; parse*-ehpat/optional : stx DeclEnv -> (list EllipsisHeadPattern stx)
(define (parse*-ehpat/optional stx decls)
(define-values (head-stx head iattrs name too-many-msg defaults)
(parse*-optional-pattern stx decls eh-optional-directive-table))
(list (make ehpat iattrs
head
(make rep:optional name too-many-msg defaults))
head-stx))
;; parse*-ehpat/once : stx DeclEnv -> (list EllipsisHeadPattern stx)
(define (parse*-ehpat/once stx decls)
(syntax-case stx (~once)
[(~once p . options)
(let* ([head (parse-head-pattern #'p decls)]
[chunks
(parse-keyword-options/eol #'options
(list (list '#:too-few check-expression)
(list '#:too-many check-expression)
(list '#:name check-expression))
#:context stx)]
[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)])
(list (make ehpat (pattern-attrs head)
head
(make rep:once name too-few-msg too-many-msg))
#'p))]))
;; parse*-ehpat/bounds : stx DeclEnv -> (list EllipsisHeadPattern stx)
(define (parse*-ehpat/bounds stx decls)
(syntax-case stx (~between)
[(~between p min max . options)
(let ()
(define 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)]
[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)])
(list (make ehpat (map increase-depth (pattern-attrs head))
head
(make rep:bounds #'min #'max
name too-few-msg too-many-msg))
#'p)))]))
;; -----
;; 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)
(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))]
[(cons (list '#:do do-stx stmts) rest)
(cons (make clause:do stmts)
(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 (parse-argu null))]
[(#:declare name (sc expr ...))
(identifier? #'sc)
(add-decl* decls #'name #'sc (parse-argu (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 argu)
(declenv-put-stxclass decls id sc-name argu))
(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 (in-list (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 (in-list (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 (in-list (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 (in-list (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/record 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 (in-list (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 (in-list (stx->list stx))])
(check-conventions x ctx)))
;; returns (cons Conventions (listof syntax))
(define (check-conventions stx ctx)
(define (elaborate conventions-id argu)
(let ([cs (syntax-local-value/record conventions-id conventions?)])
(unless cs
(raise-syntax-error #f "expected identifier defined as a conventions"
ctx conventions-id))
(cons cs argu)))
(syntax-case stx ()
[(conventions arg ...)
(identifier? #'conventions)
(elaborate #'conventions (parse-argu (syntax->list #'(arg ...))))]
[conventions
(identifier? #'conventions)
(elaborate #'conventions no-arguments)]
[_
(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 (in-list (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 no-arguments)]
[(sc arg ...)
(identifier? #'sc)
(make den:class rx #'sc (parse-argu (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 (in-list (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)]))
(define (check-stmt-list stx ctx)
(syntax-case stx ()
[(e ...)
(syntax->list #'(e ...))]
[_
(raise-syntax-error #f "expected list of expressions and definitions" ctx stx)]))
;; Arguments and Arities
;; parse-argu : (listof stx) -> Arguments
(define (parse-argu args #:context [ctx (current-syntax-context)])
(parameterize ((current-syntax-context ctx))
(define (loop args rpargs rkws rkwargs)
(cond [(null? args)
(arguments (reverse rpargs) (reverse rkws) (reverse rkwargs))]
[(keyword? (syntax-e (car args)))
(let ([kw (syntax-e (car args))]
[rest (cdr args)])
(cond [(memq kw rkws)
(wrong-syntax (car args) "duplicate keyword")]
[(null? rest)
(wrong-syntax (car args)
"missing argument expression after keyword")]
#| Overzealous, perhaps?
[(keyword? (syntax-e (car rest)))
(wrong-syntax (car rest) "expected expression following keyword")]
|#
[else
(loop (cdr rest) rpargs (cons kw rkws) (cons (car rest) rkwargs))]))]
[else
(loop (cdr args) (cons (car args) rpargs) rkws rkwargs)]))
(loop args null null null)))
;; parse-kw-formals : stx -> Arity
(define (parse-kw-formals formals #:context [ctx (current-syntax-context)])
(parameterize ((current-syntax-context ctx))
(define id-h (make-bound-id-table))
(define kw-h (make-hasheq)) ;; keyword => 'mandatory or 'optional
(define pos 0)
(define opts 0)
(define (add-id! id)
(when (bound-id-table-ref id-h id #f)
(wrong-syntax id "duplicate formal parameter" ))
(bound-id-table-set! id-h id #t))
(define (loop formals)
(cond [(and (stx-pair? formals) (keyword? (syntax-e (stx-car formals))))
(let* ([kw-stx (stx-car formals)]
[kw (syntax-e kw-stx)]
[rest (stx-cdr formals)])
(cond [(hash-ref kw-h kw #f)
(wrong-syntax kw-stx "duplicate keyword")]
[(stx-null? rest)
(wrong-syntax kw-stx "missing formal parameter after keyword")]
[else
(let-values ([(formal opt?) (parse-formal (stx-car rest))])
(add-id! formal)
(hash-set! kw-h kw (if opt? 'optional 'mandatory)))
(loop (stx-cdr rest))]))]
[(stx-pair? formals)
(let-values ([(formal opt?) (parse-formal (stx-car formals))])
(when (and (positive? opts) (not opt?))
(wrong-syntax (stx-car formals)
"mandatory argument may not follow optional argument"))
(add-id! formal)
(set! pos (add1 pos))
(when opt? (set! opts (add1 opts)))
(loop (stx-cdr formals)))]
[(identifier? formals)
(add-id! formals)
(finish #t)]
[(stx-null? formals)
(finish #f)]
[else
(wrong-syntax formals "bad argument sequence")]))
(define (finish has-rest?)
(arity (- pos opts)
(if has-rest? +inf.0 pos)
(sort (for/list ([(k v) (in-hash kw-h)]
#:when (eq? v 'mandatory))
k)
keyword<?)
(sort (hash-map kw-h (lambda (k v) k))
keyword<?)))
(loop formals)))
;; parse-formal : stx -> (values id bool)
(define (parse-formal formal)
(syntax-case formal ()
[param
(identifier? #'param)
(values #'param #f)]
[(param default)
(identifier? #'param)
(values #'param #t)]
[_
(wrong-syntax formal
"expected formal parameter with optional default")]))
;; Directive tables
;; common-parse-directive-table
(define common-parse-directive-table
(list (list '#:disable-colon-notation)
(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)
(list '#:no-delimit-cut)
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)
(list '#:do check-stmt-list)))
;; 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 '#:opaque)))
;; 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 (lambda (stx ctx) stx))
phase-directive-table))
;; var-pattern-directive-table
(define var-pattern-directive-table
(list (list '#:attr-name-separator check-stx-string)))