racket/collects/syntax/private/stxparse/sc.rkt
2010-06-02 17:19:12 -06:00

292 lines
10 KiB
Racket

#lang racket/base
(require (for-syntax racket/base
racket/private/sc
unstable/syntax
unstable/struct
"minimatch.ss"
"../util/txlift.ss"
"rep-data.ss"
"rep.ss")
racket/list
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
syntax-class-possible-errors
debug-rhs
debug-pattern
debug-parse
syntax-parse
syntax-parser
pattern
~var
~datum
~literal
~and
~or
~not
~seq
~between
~once
~optional
~rest
~describe
~!
~bind
~fail
;; ~early-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)]
[commit? (rhs-commit? the-rhs)])
#`(begin (define-syntax name
(make stxclass 'name '(arg ...)
'attrs
((syntax-local-certifier) (quote-syntax parser))
((syntax-local-certifier) (quote-syntax description))
'#,splicing?
'commit?))
(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 param ...) rule ...)
(let ([params (syntax->list #'(param ...))])
(for ([x (syntax->list #'(name param ...))])
(unless (identifier? x)
(raise-syntax-error #f "expected identifier" stx x)))
(let ()
(define rules (check-conventions-rules #'(rule ...) stx))
(define rxs (map car rules))
(define dens0 (map cadr rules))
(define den+defs-list
(for/list ([den0 dens0])
(let-values ([(den defs) (create-aux-def den0)])
(cons den defs))))
(define dens (map car den+defs-list))
(define defs (apply append (map cdr den+defs-list)))
(define/with-syntax (rx ...) rxs)
(define/with-syntax (def ...) defs)
(define/with-syntax (parser ...)
(map den:delayed-parser dens))
(define/with-syntax (description ...)
(map den:delayed-description dens))
(define/with-syntax (class-name ...)
(map den:delayed-class dens))
#'(begin
(define-syntax name
(make-conventions
(quote-syntax get-procedures)
(lambda ()
(let ([class-names (list (quote-syntax class-name) ...)])
(map list
(list 'rx ...)
(map make-den:delayed
(generate-temporaries class-names)
(generate-temporaries class-names)
class-names))))))
(define get-procedures
(lambda (param ...)
def ...
(values (list parser ...)
(list description ...)))))))]
[(define-conventions name rule ...)
(identifier? #'name)
#'(define-conventions (name) rule ...)]))
(define-syntax (define-literal-set stx)
(syntax-case stx ()
[(define-literal-set name (lit ...))
(let ([phase-of-definition (syntax-local-phase-level)])
(unless (identifier? #'name)
(raise-syntax-error #f "expected identifier" stx #'name))
(let ([lits (check-literals-list/litset #'(lit ...) stx)])
(with-syntax ([((internal external) ...) lits])
#`(begin
(define phase-of-literals
(phase-of-enclosing-module))
(define-syntax name
(make-literalset
(list (list 'internal (quote-syntax external)) ...)
(quote-syntax phase-of-literals)))
(begin-for-syntax/once
(for ([x (syntax->list #'(external ...))])
(unless (identifier-binding x 0)
(raise-syntax-error #f "literal is unbound in phase 0"
(quote-syntax #,stx) x))))))))]))
(define-syntax (phase-of-enclosing-module stx)
(syntax-case stx ()
[(poem)
(let ([phase-within-module (syntax-local-phase-level)])
#`(let ([phase-of-this-expression
(variable-reference->phase (#%variable-reference))])
(- phase-of-this-expression
#,(if (zero? phase-within-module) 0 1))))]))
#|
Literal sets: The goal is for literals to refer to their bindings at
phase 0 relative to the enclosing module
Use cases, explained:
1) module X with def-lit-set is required-for-syntax
phase-of-mod-inst = 1
phase-of-def = 0
literals looked up at abs phase 1
which is phase 0 rel to module X
2) module X with local def-lit-set within define-syntax
phase-of-mod-inst = 1 (mod at 0, but +1 within define-syntax)
phase-of-def = 1
literals looked up at abs phase 0
which is phase 0 rel to module X
3) module X with def-lit-set in phase-2 position (really uncommon case!)
phase-of-mod-inst = 1 (not 2, apparently)
phase-of-def = 2
literals looked up at abs phase 0
(that's why the weird (if (z?) 0 1) term)
|#
;; ----
(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 (syntax->datum #'attrs) (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 (syntax-class-possible-errors stx)
(syntax-case stx ()
[(_ s)
(parameterize ((current-syntax-context stx))
(with-syntax ([p (stxclass-parser-name (get-stxclass #'s))])
#'(remove-duplicates
(map interpret-error-expression
(parser-errors p)))))]))
(define-syntax (debug-rhs stx)
(syntax-case stx ()
[(debug-rhs rhs)
(let ([rhs (parse-rhs #'rhs #f #f #: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)])]))