racket/collects/syntax/private/stxparse/sc.ss
2009-11-11 08:23:12 +00:00

209 lines
7.0 KiB
Scheme

#lang scheme/base
(require (for-syntax scheme/base
scheme/private/sc
unstable/syntax
unstable/struct
"rep-data.ss"
"rep.ss")
syntax/stx
"parse.ss"
"runtime.ss"
"runtime-prose.ss")
(provide define-syntax-class
define-splicing-syntax-class
define-literal-set
define-conventions
syntax-class-parse
syntax-class-attributes
debug-rhs
debug-pattern
debug-parse
syntax-parse
syntax-parser
pattern
~var
~datum
~literal
~and
~or
~not
~seq
~bounds
~once
~optional
~rest
~describe
~!
~bind
~fail
~parse
attribute
this-syntax)
(begin-for-syntax
(define (defstxclass stx name args rhss splicing?)
(with-syntax ([name name]
[(arg ...) args]
[rhss rhss])
(let ([the-rhs
(parameterize ((current-syntax-context stx))
(parse-rhs #'rhss #f splicing? #:context stx))])
(with-syntax ([parser (generate-temporary
(format-symbol "parse-~a" (syntax-e #'name)))]
[attrs (rhs-attrs the-rhs)])
#`(begin (define-syntax name
(make stxclass 'name '(arg ...)
'attrs
((syntax-local-certifier) (quote-syntax parser))
((syntax-local-certifier) (quote-syntax description))
'#,splicing?))
(define-values (parser description)
(functions/rhs name (arg ...) attrs rhss #,splicing? #,stx))))))))
(define-syntax (define-syntax-class stx)
(syntax-case stx ()
[(define-syntax-class name . rhss)
(identifier? #'name)
(defstxclass stx #'name #'() #'rhss #f)]
[(define-syntax-class (name arg ...) . rhss)
(andmap identifier? (syntax->list #'(name arg ...)))
(defstxclass stx #'name #'(arg ...) #'rhss #f)]))
(define-syntax (define-splicing-syntax-class stx)
(syntax-case stx ()
[(define-splicing-syntax-class name . rhss)
(identifier? #'name)
(defstxclass stx #'name #'() #'rhss #t)]
[(define-splicing-syntax-class (name arg ...) . rhss)
(andmap identifier? (syntax->list #'(name arg ...)))
(defstxclass stx #'name #'(arg ...) #'rhss #t)]))
(define-syntax (define-conventions stx)
(syntax-case stx ()
[(define-conventions name rule ...)
(begin
(unless (identifier? #'name)
(raise-syntax-error #f "expected identifier" stx #'name))
(with-syntax ([([entry (def ...)] ...)
(for/list ([line (check-conventions-rules #'(rule ...) stx)])
(let ([rx (car line)]
[sc (car (cadr line))]
[args (cadr (cadr line))])
(let-values ([(parser description attrs defs)
(create-aux-def (list 'stxclass rx sc args))])
(list #`(list (quote #,rx)
(list 'parser
(quote-syntax #,parser)
(quote-syntax #,description)
(quote #,attrs)))
defs))))])
#'(begin
def ... ...
(define-syntax name
(make-conventions
(list entry ...))))))]))
(define-syntax (define-literal-set stx)
(syntax-case stx ()
[(define-literal-set name (lit ...))
(begin
(unless (identifier? #'name)
(raise-syntax-error #f "expected identifier" stx #'name))
(let ([lits (check-literals-list #'(lit ...) stx)])
(with-syntax ([((internal external) ...) lits])
#'(define-syntax name
(make-literalset
(list (list 'internal (quote-syntax external)) ...))))))]))
;; ----
(define-syntax (functions/rhs stx)
(syntax-case stx ()
[(functions/S-rhs name args attrs rhss splicing? ctx)
(with-disappeared-uses
(let ([rhs
(parameterize ((current-syntax-context #'ctx))
(parse-rhs #'rhss #t (syntax-e #'splicing?) #:context #'ctx))])
#`(let ([get-description
(lambda args
#,(or (rhs-description rhs)
#'(symbol->string 'name)))])
(values (parse:rhs #,rhs
attrs
args
get-description
splicing?)
get-description))))]))
(define-syntax (syntax-class-parse stx)
(syntax-case stx ()
[(_ s x arg ...)
(parameterize ((current-syntax-context stx))
(let* ([arg-count (length (syntax->list #'(arg ...)))]
[stxclass (get-stxclass/check-arg-count #'s arg-count)]
[attrs (stxclass-attrs stxclass)])
(with-syntax ([parser (stxclass-parser-name stxclass)]
[(name ...) (map attr-name attrs)]
[(depth ...) (map attr-depth attrs)])
#'(let ([raw (parser x arg ...)])
(if (ok? raw)
(map vector '(name ...) '(depth ...) raw)
raw)))))]))
(define-syntax (syntax-class-attributes stx)
(syntax-case stx ()
[(_ s)
(parameterize ((current-syntax-context stx))
(let ([attrs (stxclass-attrs (get-stxclass #'s))])
(with-syntax ([(a ...) (map attr-name attrs)]
[(depth ...) (map attr-depth attrs)])
#'(quote ((a depth) ...)))))]))
(define-syntax (debug-rhs stx)
(syntax-case stx ()
[(debug-rhs rhs)
(let ([rhs (parse-rhs #'rhs #t #:context stx)])
#`(quote #,rhs))]))
(define-syntax (debug-pattern stx)
(syntax-case stx ()
[(debug-pattern p)
(let ([p (parse-whole-pattern #'p (new-declenv null) #:context stx)])
#`(quote #,p))]))
(define-syntax-rule (debug-parse x p)
(let/ec escape
(parameterize ((current-failure-handler
(lambda (_ f)
(escape (failure->sexpr f)
(failure->sexpr (simplify-failure f))))))
(syntax-parse x [p 'success]))))
(define-syntax (syntax-parse stx)
(syntax-case stx ()
[(syntax-parse stx-expr . clauses)
(quasisyntax/loc stx
(let ([x (datum->syntax #f stx-expr)])
(parse:clauses x clauses #,stx)))]))
(define-syntax (syntax-parser stx)
(syntax-case stx ()
[(syntax-parser . clauses)
(quasisyntax/loc stx
(lambda (x)
(let ([x (datum->syntax #f x)])
(parse:clauses x clauses #,stx))))]))
(define-syntax with-patterns
(syntax-rules ()
[(with-patterns () . b)
(let () . b)]
[(with-patterns ([p x] . more) . b)
(syntax-parse x [p (with-patterns more . b)])]))