racket/collects/syntax/private/stxparse/rep-data.rkt
Ryan Culpepper eff9147ddc syntax/parse: literals, literal-sets, and phases (todo: docs)
typed-scheme: added missing import for literal
2010-05-04 14:12:49 -06:00

292 lines
9.3 KiB
Racket

#lang racket/base
(require racket/contract/base
racket/dict
racket/list
syntax/stx
syntax/id-table
"../util.ss"
"minimatch.ss"
"rep-attrs.ss"
"rep-patterns.ss")
(provide (all-from-out "rep-attrs.ss")
(all-from-out "rep-patterns.ss")
(struct-out stxclass)
stxclass/s?
stxclass/h?
(struct-out attr)
(struct-out rhs)
(struct-out variant)
(struct-out clause:fail)
(struct-out clause:with)
(struct-out clause:attr)
(struct-out conventions)
(struct-out literalset))
#|
NOTES
syntax-class protocol
---------------------
Two kinds of syntax class: commit? = #t, commit? = #f
let syntax-class SC have params (P ...)
if commit? = #t
parser : Stx P ... -> (U list expectation)
if commit? = #f
parser : Stx ((U list expect) FailFunction -> Answer) P ... -> Answer
conventions
-----------
let conventions C have params (P ...)
get-procedures :
(P ... -> (values (listof ParserFun) (listof DescriptionFun)))
|#
#|
A stxclass is
(make-sc symbol (listof symbol) (list-of SAttr) identifier identifier boolean boolean)
|#
(define-struct stxclass (name params attrs parser-name description
splicing? commit?)
#:prefab)
(define (stxclass/s? x)
(and (stxclass? x) (not (stxclass-splicing? x))))
(define (stxclass/h? x)
(and (stxclass? x) (stxclass-splicing? x)))
#|
An RHS is
(make-rhs stx (listof SAttr) boolean stx/#f (listof Variant) (listof stx))
definitions: auxiliary definitions from #:declare
|#
(define-struct rhs (ostx attrs transparent? description variants definitions commit?)
#:prefab)
#|
A Variant is
(make-variant stx (listof SAttr) Pattern (listof SideClause))
|#
(define-struct variant (ostx attrs pattern sides definitions) #:prefab)
#|
A SideClause is one of
(make-clause:fail stx stx)
(make-clause:with pattern stx (listof stx))
(make-clause:attr IAttr stx)
|#
(define-struct clause:fail (condition message) #:prefab)
(define-struct clause:with (pattern expr definitions) #:prefab)
(define-struct clause:attr (attr expr) #:prefab)
#|
A Conventions is
(make-conventions id (-> (listof ConventionRule)))
A ConventionRule is (list regexp DeclEntry)
|#
(define-struct conventions (get-procedures get-rules) #:transparent)
#|
A LiteralSet is
(make-literalset (listof (list symbol id)) stx)
|#
(define-struct literalset (literals phase) #:transparent)
;; make-dummy-stxclass : identifier -> SC
;; Dummy stxclass for calculating attributes of recursive stxclasses.
(define (make-dummy-stxclass name)
(make stxclass (syntax-e name) null null #f #f #f #t))
;; Environments
#|
DeclEnv =
(make-declenv immutable-bound-id-mapping[id => DeclEntry]
(listof ConventionRule))
DeclEntry =
(make-den:lit id id ct-phase ct-phase)
(make-den:class id id (listof syntax) bool)
(make-den:parser id id (listof SAttr) bool bool)
(make-den:delayed id id id)
|#
(define-struct declenv (table conventions))
(define-struct den:lit (internal external input-phase lit-phase))
(define-struct den:class (name class args))
(define-struct den:parser (parser description attrs splicing? commit?))
(define-struct den:delayed (parser description class))
(define (new-declenv literals #:conventions [conventions null])
(make-declenv
(for/fold ([table (make-immutable-bound-id-table)])
([literal literals])
(bound-id-table-set table (car literal)
(make den:lit (first literal) (second literal)
(third literal) (fourth literal))))
conventions))
(define (declenv-lookup env id #:use-conventions? [use-conventions? #t])
(or (bound-id-table-ref (declenv-table env) id #f)
(and use-conventions?
(conventions-lookup (declenv-conventions env) id))))
(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 #:use-conventions? #f)])
(match val
[(struct den:lit (_i _e _ip _lp))
(wrong-syntax id "identifier previously declared as literal")]
[(struct den:class (name _c _a))
(if (and blame-declare? stxclass-name)
(wrong-syntax name
"identifier previously declared with syntax class ~a"
stxclass-name)
(wrong-syntax (if blame-declare? name id)
"identifier previously declared"))]
[(struct den:parser (_p _d _a _sp _c))
(wrong-syntax id "(internal error) late unbound check")]
['#f (void)])))
(define (declenv-put-stxclass env id stxclass-name args)
(declenv-check-unbound env id)
(make-declenv
(bound-id-table-set (declenv-table env) id
(make den:class id stxclass-name args))
(declenv-conventions env)))
;; declenv-update/fold : DeclEnv (Id/Regexp DeclEntry a -> DeclEntry a) a
;; -> (values DeclEnv a)
(define (declenv-update/fold env0 f acc0)
(define-values (acc1 rules1)
(for/fold ([acc acc0] [newrules null])
([rule (declenv-conventions env0)])
(let-values ([(val acc) (f (car rule) (cadr rule) acc)])
(values acc (cons (list (car rule) val) newrules)))))
(define-values (acc2 table2)
(for/fold ([acc acc1] [table (make-immutable-bound-id-table)])
([(k v) (in-dict (declenv-table env0))])
(let-values ([(val acc) (f k v acc)])
(values acc (bound-id-table-set table k val)))))
(values (make-declenv table2 (reverse rules1))
acc2))
;; returns ids in domain of env but not in given list
(define (declenv-domain-difference env ids)
(define idbm (make-bound-id-table))
(for ([id ids]) (bound-id-table-set! idbm id #t))
(for/list ([(k v) (in-dict (declenv-table env))]
#:when (or (den:class? v) (den:parser? v))
#:when (not (bound-id-table-ref idbm k #f)))
k))
;; Conventions = (listof (list regexp DeclEntry))
(define (conventions-lookup conventions id)
(let ([sym (symbol->string (syntax-e id))])
(for/or ([c conventions])
(and (regexp-match? (car c) sym) (cadr c)))))
;; Contracts
(define DeclEnv/c
(flat-named-contract 'DeclEnv declenv?))
(define DeclEntry/c
(flat-named-contract 'DeclEntry
(or/c den:lit? den:class? den:parser? den:delayed?)))
(define SideClause/c
(or/c clause:fail? clause:with? clause:attr?))
;; ct-phase = syntax, expr that computes absolute phase
;; usually = #'(syntax-local-phase-level)
(define ct-phase/c syntax?)
(provide (struct-out den:lit)
(struct-out den:class)
(struct-out den:parser)
(struct-out den:delayed))
(provide/contract
[DeclEnv/c contract?]
[DeclEntry/c contract?]
[SideClause/c contract?]
[ct-phase/c contract?]
[make-dummy-stxclass (-> identifier? stxclass?)]
[stxclass-lookup-config (parameter/c (symbols 'no 'try 'yes))]
[new-declenv
(->* [(listof (list/c identifier? identifier? ct-phase/c ct-phase/c))]
[#:conventions list?]
DeclEnv/c)]
[declenv-lookup
(-> DeclEnv/c identifier? any)]
[declenv-put-stxclass
(-> DeclEnv/c identifier? identifier? (listof syntax?)
DeclEnv/c)]
[declenv-domain-difference
(-> DeclEnv/c (listof identifier?)
(listof identifier?))]
[declenv-update/fold
(-> DeclEnv/c
(-> (or/c identifier? regexp?) DeclEntry/c any/c (values DeclEntry/c any/c))
any/c
(values DeclEnv/c any/c))]
[get-stxclass
(-> identifier? any)]
[get-stxclass/check-arg-count
(-> identifier? exact-nonnegative-integer? any)]
[split-id/get-stxclass
(-> identifier? DeclEnv/c any)])
;; stxclass-lookup-config : (parameterof (U 'no 'try 'yes))
;; 'no means don't lookup, always use dummy (no nested attrs)
;; 'try means lookup, but on failure use dummy (-> nested attrs only from prev.)
;; 'yes means lookup, raise error on failure
(define stxclass-lookup-config (make-parameter 'yes))
(define (get-stxclass id)
(define config (stxclass-lookup-config))
(if (eq? config 'no)
(make-dummy-stxclass id)
(cond [(syntax-local-value/catch id stxclass?) => values]
[(eq? config 'try)
(make-dummy-stxclass id)]
[else (wrong-syntax id "not defined as syntax class")])))
(define (get-stxclass/check-arg-count id arg-count)
(let* ([sc (get-stxclass id)]
[expected-arg-count (length (stxclass-params sc))])
(unless (or (= expected-arg-count arg-count)
(memq (stxclass-lookup-config) '(try no)))
;; (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)))]
[else (values id0 #f)]))