racket/collects/stxclass/private/rep-data.ss
2009-02-18 04:01:52 +00:00

450 lines
16 KiB
Scheme

#lang scheme/base
(require scheme/contract
scheme/match
syntax/stx
syntax/boundmap
"../util.ss")
(provide (struct-out sc)
(struct-out attr)
(struct-out rhs)
(struct-out rhs:union)
(struct-out rhs:basic)
(struct-out rhs:pattern)
(struct-out pattern)
(struct-out pat:id)
(struct-out pat:datum)
(struct-out pat:literal)
(struct-out pat:compound)
(struct-out pat:gseq)
(struct-out pat:and)
(struct-out pat:orseq)
(struct-out kind)
(struct-out head)
(struct-out clause:when)
(struct-out clause:with))
;; An SC is one of (make-sc symbol (listof symbol) (list-of SAttr) identifier)
(define-struct sc (name inputs attrs parser-name description)
#:property prop:procedure (lambda (self stx) (sc-parser-name self))
#:transparent)
;; An IAttr is (make-attr identifier number (listof SAttr))
;; An SAttr is (make-attr symbol number (listof SAttr))
(define-struct attr (name depth inner)
#:transparent)
;; RHSBase is stx (listof SAttr) boolean stx/#f
(define-struct rhs (orig-stx attrs transparent? description)
#:transparent)
;; A RHS is one of
;; (make-rhs:union <RHSBase> (listof RHS))
;; (make-rhs:basic <RHSBase> stx)
(define-struct (rhs:union rhs) (patterns)
#:transparent)
(define-struct (rhs:basic rhs) (parser)
#:transparent)
;; An RHSPattern is
;; (make-rhs:pattern stx (listof SAttr) Pattern Env Env (listof SideClause))
(define-struct rhs:pattern (stx attrs pattern decls remap whens)
#:transparent)
;; A Pattern is one of
;; (make-pat:id <Pattern> identifier SC/#f (listof stx))
;; (make-pat:datum <Pattern> datum)
;; (make-pat:pair <Pattern> Pattern Pattern)
;; (make-pat:seq <Pattern> Pattern Pattern)
;; (make-pat:gseq <Pattern> (listof Head) Pattern)
;; (make-pat:and <Pattern> string/#f (listof Pattern))
;; (make-pat:compound <Pattern> Kind (listof Pattern))
;; when <Pattern> = stx (listof IAttr) number
(define-struct pattern (orig-stx attrs depth) #:transparent)
(define-struct (pat:id pattern) (name stxclass args) #:transparent)
(define-struct (pat:datum pattern) (datum) #:transparent)
(define-struct (pat:literal pattern) (literal) #:transparent)
(define-struct (pat:gseq pattern) (heads tail) #:transparent)
(define-struct (pat:and pattern) (description subpatterns) #:transparent)
(define-struct (pat:orseq pattern) (heads) #:transparent)
(define-struct (pat:compound pattern) (kind patterns) #:transparent)
;; A Kind is (make-kind id (listof (id id -> stx)) (listof (FCE id -> FCE)))
(define-struct kind (predicate selectors frontier-procs) #:transparent)
;; A Head is
;; (make-head stx (listof IAttr) nat (listof Pattern) nat/f nat/f boolean id/#f stx/#f)
(define-struct head (orig-stx attrs depth ps min max as-list?) #:transparent)
;; A SideClause is one of
;; (make-clause:with pattern stx)
;; (make-clause:when stx)
(define-struct clause:with (pattern expr) #:transparent)
(define-struct clause:when (expr) #:transparent)
;; make-empty-sc : identifier -> SC
;; Dummy stxclass for calculating attributes of recursive stxclasses.
(define (make-empty-sc name)
(make sc (syntax-e name) null null #f #f))
(define (iattr? a)
(and (attr? a) (identifier? (attr-name a))))
(define (sattr? a)
(and (attr? a) (symbol? (attr-name a))))
;; Environments
;; DeclEnv maps [id => DeclEntry]
;; DeclEntry =
;; (list 'literal id id)
;; (list 'stxclass id id (listof stx))
;; #f
(define-struct declenv (bm))
(define (new-declenv literals)
(let ([decls (make-declenv (make-bound-identifier-mapping))])
(for ([literal literals])
(declenv-put-literal decls (car literal) (cadr literal)))
decls))
(define (declenv-lookup env id)
(bound-identifier-mapping-get (declenv-bm env) id (lambda () #f)))
(define (declenv-check-unbound env id [stxclass-name #f]
#:blame-declare? [blame-declare? #f])
;; Order goes: literals, pattern, declares
;; So blame-declare? only applies to stxclass declares
(let ([val (declenv-lookup env id)])
(when val
(cond [(eq? 'literal (car val))
(wrong-syntax id "identifier previously declared as literal")]
[(and blame-declare? stxclass-name)
(wrong-syntax (cadr val)
"identifier previously declared with syntax class ~a"
stxclass-name)]
[else
(wrong-syntax (if blame-declare? (cadr val) id)
"identifier previously declared")]))))
(define (declenv-put-literal env internal-id lit-id)
(declenv-check-unbound env internal-id)
(bound-identifier-mapping-put! (declenv-bm env) internal-id
(list 'literal internal-id lit-id)))
(define (declenv-put-stxclass env id stxclass-name args)
(declenv-check-unbound env id)
(bound-identifier-mapping-put! (declenv-bm env) id
(list 'stxclass id stxclass-name args)))
;; returns ids in domain of env but not in given list
(define (declenv-domain-difference env ids)
(define idbm (make-bound-identifier-mapping))
(define excess null)
(for ([id ids]) (bound-identifier-mapping-put! idbm id #t))
(bound-identifier-mapping-for-each
(declenv-bm env)
(lambda (k v)
(when (and (pair? v) (eq? (car v) 'stxclass))
(unless (bound-identifier-mapping-get idbm k (lambda () #f))
(set! excess (cons k excess))))))
excess)
;; A RemapEnv is a bound-identifier-mapping
(define (new-remapenv)
(make-bound-identifier-mapping))
(define (remapenv-lookup env id)
(bound-identifier-mapping-get env id (lambda () (syntax-e id))))
(define (remapenv-put env id sym)
(bound-identifier-mapping-put! env id sym))
(define (remapenv-domain env)
(bound-identifier-mapping-map env (lambda (k v) k)))
(define trivial-remap
(new-remapenv))
;; Contracts
(define DeclEnv/c
(flat-named-contract "DeclEnv/c" declenv?))
(define RemapEnv/c
(flat-named-contract "RemapEnv/c" bound-identifier-mapping?))
(define SideClause/c
(or/c clause:with? clause:when?))
(provide/contract
[DeclEnv/c contract?]
[RemapEnv/c contract?]
[SideClause/c contract?]
[make-empty-sc (-> identifier? sc?)]
[allow-unbound-stxclasses (parameter/c boolean?)]
[iattr? (any/c . -> . boolean?)]
[sattr? (any/c . -> . boolean?)]
[new-declenv
(-> (listof (list/c identifier? identifier?)) DeclEnv/c)]
[declenv-lookup
(-> declenv? identifier? any)]
[declenv-put-literal
(-> declenv? identifier? identifier? any)]
[declenv-put-stxclass
(-> declenv? identifier? identifier? (listof syntax?)
any)]
[declenv-domain-difference
(-> declenv? (listof identifier?)
(listof identifier?))]
[new-remapenv
(-> RemapEnv/c)]
[remapenv-lookup
(-> RemapEnv/c identifier? symbol?)]
[remapenv-put
(-> RemapEnv/c identifier? symbol? any)]
[remapenv-domain
(-> RemapEnv/c list?)]
[trivial-remap
RemapEnv/c]
[iattr->sattr (iattr? . -> . sattr?)]
[rename-attr
(attr? symbol? . -> . sattr?)]
[iattrs->sattrs
(-> (listof iattr?) RemapEnv/c
(listof sattr?))]
[sattr->iattr/id (sattr? identifier? . -> . iattr?)]
[get-stxclass
(-> identifier? any)]
[get-stxclass/check-arg-count
(-> identifier? exact-nonnegative-integer? any)]
[split-id/get-stxclass
(-> identifier? DeclEnv/c any)]
[intersect-attrss ((listof (listof sattr?)) syntax? . -> . (listof sattr?))]
[join-attrs (sattr? sattr? syntax? . -> . sattr?)]
[reorder-iattrs
(-> (listof sattr?) (listof iattr?) RemapEnv/c
(listof iattr?))]
[restrict-iattrs
(-> (listof sattr?) (listof iattr?) RemapEnv/c
(listof iattr?))]
[flatten-sattrs
(->* [(listof sattr?)]
[exact-integer? (or/c symbol? false/c)]
(listof sattr?))]
[intersect-sattrs ((listof sattr?) (listof sattr?) . -> . (listof sattr?))]
[flatten-attrs*
(->* [(listof iattr?)]
[exact-nonnegative-integer? any/c any/c]
(listof iattr?))]
[append-attrs ((listof (listof iattr?)) . -> . (listof iattr?))]
[lookup-sattr (symbol? (listof sattr?) . -> . (or/c sattr? false/c))]
[lookup-iattr (identifier? (listof iattr?) . -> . (or/c iattr? false/c))]
)
(define allow-unbound-stxclasses (make-parameter #f))
(define (iattr->sattr a)
(match a
[(struct attr (name depth inner))
(make attr (syntax-e name) depth inner)]))
(define (rename-attr a name)
(make attr name (attr-depth a) (attr-inner a)))
(define (iattrs->sattrs as remap)
(if (pair? as)
(let ([name* (remapenv-lookup remap (attr-name (car as)))])
(if name*
(cons (rename-attr (car as) name*)
(iattrs->sattrs (cdr as) remap))
(iattrs->sattrs (cdr as) remap)))
null))
(define (sattr->iattr/id a id)
(match a
[(struct attr (name depth inner))
(make attr (datum->syntax id name id) depth inner)]))
(define (get-stxclass id)
(define (no-good)
(if (allow-unbound-stxclasses)
(make-empty-sc id)
(wrong-syntax id "not defined as syntax class")))
(let ([sc (syntax-local-value/catch id sc?)])
(if (sc? sc)
sc
(no-good))))
(define (get-stxclass/check-arg-count id arg-count)
(let* ([sc (get-stxclass id)]
[expected-arg-count (length (sc-inputs sc))])
(unless (or (= expected-arg-count arg-count)
(allow-unbound-stxclasses))
;; (above: don't check error if stxclass may not be defined yet)
(wrong-syntax id
"too few arguments for syntax-class ~a (expected ~s)"
(syntax-e id)
expected-arg-count))
sc))
(define (split-id/get-stxclass id0 decls)
(cond [(regexp-match #rx"^([^:]*):(.+)$" (symbol->string (syntax-e id0)))
=> (lambda (m)
(define id
(datum->syntax id0 (string->symbol (cadr m)) id0 id0))
(define scname
(datum->syntax id0 (string->symbol (caddr m)) id0 id0))
(declenv-check-unbound decls id (syntax-e scname)
#:blame-declare? #t)
(let ([sc (get-stxclass/check-arg-count scname 0)])
(values id sc null)))]
[else (values id0 #f null)]))
;; intersect-attrss : (listof (listof SAttr)) stx -> (listof SAttr)
(define (intersect-attrss attrss blamestx)
(cond [(null? attrss) null]
[else
(let* ([namess (map (lambda (attrs) (map attr-name attrs)) attrss)]
[names (filter (lambda (s)
(andmap (lambda (names) (memq s names))
(cdr namess)))
(car namess))]
[ht (make-hasheq)]
[put (lambda (attr) (hash-set! ht (attr-name attr) attr))]
[fetch-like (lambda (attr) (hash-ref ht (attr-name attr) #f))])
(for* ([attrs attrss]
[attr attrs]
#:when (memq (attr-name attr) names))
(put (join-attrs attr (fetch-like attr) blamestx)))
(sort (hash-map ht (lambda (k v) v))
(lambda (a b)
(string<? (symbol->string (attr-name a))
(symbol->string (attr-name b))))))]))
;; join-attrs : SAttr SAttr stx -> SAttr
(define (join-attrs a b blamestx)
(define (complain str . args)
(apply wrong-syntax blamestx str args))
(if (not b)
a
(begin
(unless (equal? (attr-depth a) (attr-depth b))
(complain "attribute '~a'occurs with different nesting depth"
(attr-name a)))
(make attr (attr-name a)
(attr-depth a)
(intersect-attrss (list (attr-inner a) (attr-inner b))
blamestx)))))
;; reorder-iattrs : (listof SAttr) (listof IAttr) RemapEnv/c -> (listof IAttr)
;; Reorders iattrs (and restricts) based on relsattrs
;; If a relsattr is not found, or if depth or contents mismatches, raises error.
(define (reorder-iattrs relsattrs iattrs remap)
(let ([ht (make-hasheq)])
(for ([iattr iattrs])
(let ([remap-name (remapenv-lookup remap (attr-name iattr))])
(hash-set! ht remap-name iattr)))
(let loop ([relsattrs relsattrs])
(match relsattrs
['() null]
[(cons (struct attr (name depth inner)) rest)
(let ([iattr (hash-ref ht name #f)])
(unless iattr
(wrong-syntax #f "required attribute is not defined: ~s" name))
(unless (= (attr-depth iattr) depth)
(wrong-syntax (attr-name iattr)
"attribute has wrong depth (expected ~s, found ~s)"
depth (attr-depth iattr)))
(cons (make attr (attr-name iattr)
(attr-depth iattr)
(intersect-sattrs inner (attr-inner iattr)))
(loop rest)))]))))
;; restrict-iattrs : (listof SAttr) (listof IAttr) RemapEnv/c -> (listof IAttr)
;; Preserves order of iattrs
(define (restrict-iattrs relsattrs iattrs remap)
(match iattrs
['() null]
[(cons (struct attr (name depth inner)) rest)
(let ([sattr (lookup-sattr (remapenv-lookup remap name) relsattrs)])
(if (and sattr (= depth (attr-depth sattr)))
(cons (make attr name depth
(intersect-sattrs inner (attr-inner sattr)))
(restrict-iattrs relsattrs (cdr iattrs) remap))
(restrict-iattrs relsattrs (cdr iattrs) remap)))]))
;; flatten-sattrs : (listof SAttr) num symbol -> (listof SAttr)
(define (flatten-sattrs sattrs [depth-delta 0] [prefix #f])
(match sattrs
['()
null]
[(cons (struct attr (name depth nested)) rest)
(let ([prefixed-name
(if prefix
(format-symbol "~a.~a" prefix name)
name)])
(append (list (make attr prefixed-name
(+ depth-delta depth)
null))
(flatten-sattrs nested (+ depth depth-delta) prefixed-name)
(flatten-sattrs rest depth-delta prefix)))]))
;; intersect-sattrs : (listof SAttr) (listof SAttr) -> (listof SAttr)
;; Preserves order of first list of attrs.
(define (intersect-sattrs as bs)
(match as
['() null]
[(cons (struct attr (name depth inner)) rest)
(let ([b (lookup-sattr name bs)])
(if (and b (= depth (attr-depth b)))
(cons (make attr name depth (intersect-sattrs inner (attr-inner b)))
(intersect-sattrs (cdr as) bs))
(intersect-sattrs (cdr as) bs)))]))
;; flatten-attrs* : (listof attr) num symbol stx -> (listof attr)
(define (flatten-attrs* attrs [depth-delta 0] [prefix #f] [ctx #f])
(match attrs
['()
null]
[(cons (struct attr (name depth nested)) rest)
(let ([prefixed-name
(if prefix
(format-symbol "~a.~a" prefix name)
(syntax-e name))]
[ctx (or ctx name)])
(append (list (make attr (if ctx (datum->syntax ctx prefixed-name) name)
(+ depth-delta depth)
null))
(flatten-attrs* nested (+ depth depth-delta) prefixed-name ctx)
(flatten-attrs* rest depth-delta prefix ctx)))]))
;; append-attrs : (listof (listof IAttr)) -> (listof IAttr)
(define (append-attrs attrss)
(let* ([all (apply append attrss)]
[names (map attr-name all)]
[dup (check-duplicate-identifier names)])
(when dup
(wrong-syntax dup "duplicate pattern variable"))
all))
(define (lookup-sattr name sattrs)
(cond [(null? sattrs) #f]
[(eq? name (attr-name (car sattrs))) (car sattrs)]
[else (lookup-sattr name (cdr sattrs))]))
(define (lookup-iattr name iattrs)
(cond [(null? iattrs) #f]
[(bound-identifier=? name (attr-name (car iattrs))) (car iattrs)]
[else (lookup-iattr name (cdr iattrs))]))