racket/collects/web-server/lang/defun.ss
2008-08-25 19:57:34 +00:00

143 lines
5.9 KiB
Scheme

#lang scheme/base
(require (for-template scheme/base)
syntax/kerncase
syntax/free-vars
scheme/contract
mzlib/list
mzlib/plt-match
"util.ss"
"../private/closure.ss")
(provide/contract
[defun (syntax? . -> . (values syntax? (listof syntax?)))])
; make-new-clouse-label : (syntax -> syntax) syntax -> syntax
(define (make-new-closure-label labeling stx)
(labeling stx))
; defun : syntax[1] -> (values syntax?[2] (listof syntax?)[3])
; defunctionalizes the first syntax, returning the second and the lifted lambdas [3]
(define (defun stx)
(recertify/new-defs
stx
(lambda ()
(kernel-syntax-case
stx (transformer?)
[(begin be ...)
(let-values ([(nbes defs) (defun* (syntax->list #'(be ...)))])
(values (quasisyntax/loc stx (begin #,@nbes))
defs))]
[(begin0 be ...)
(let-values ([(nbes defs) (defun* (syntax->list #'(be ...)))])
(values (quasisyntax/loc stx (begin0 #,@nbes))
defs))]
[(set! v ve)
(let-values ([(nve defs) (defun #'ve)])
(values (quasisyntax/loc stx (set! v #,nve))
defs))]
[(let-values ([(v ...) ve] ...) be ...)
(let-values ([(nves ve-defs) (defun* (syntax->list #'(ve ...)))]
[(nbes be-defs) (defun* (syntax->list #'(be ...)))])
(with-syntax ([(nve ...) nves]
[(nbe ...) nbes])
(values (syntax/loc stx (let-values ([(v ...) nve] ...) nbe ...))
(append ve-defs be-defs))))]
[(letrec-values ([(v ...) ve] ...) be ...)
(let-values ([(nves ve-defs) (defun* (syntax->list #'(ve ...)))]
[(nbes be-defs) (defun* (syntax->list #'(be ...)))])
(with-syntax ([(nve ...) nves]
[(nbe ...) nbes])
(values (syntax/loc stx (letrec-values ([(v ...) nve] ...) nbe ...))
(append ve-defs be-defs))))]
[(#%plain-lambda formals be ...)
(let-values ([(nbes be-defs) (defun* (syntax->list #'(be ...)))])
(with-syntax ([(nbe ...) nbes])
(let ([fvars (free-vars stx)])
(let-values ([(make-CLOSURE new-defs)
(make-closure-definition-syntax
(make-new-closure-label (current-code-labeling) stx)
fvars
(syntax/loc stx (#%plain-lambda formals nbe ...)))])
(values (if (empty? fvars)
(quasisyntax/loc stx (#,make-CLOSURE))
(quasisyntax/loc stx (#,make-CLOSURE (#%plain-lambda () (values #,@fvars)))))
(append be-defs new-defs))))))]
[(case-lambda [formals be ...] ...)
(let-values ([(nbes be-defs) (defun** (syntax->list #'((be ...) ...)))])
(with-syntax ([((nbe ...) ...) nbes])
(let ([fvars (free-vars stx)])
(let-values ([(make-CLOSURE new-defs)
(make-closure-definition-syntax
(make-new-closure-label (current-code-labeling) stx)
fvars
(syntax/loc stx (case-lambda [formals nbe ...] ...)))])
(values (if (empty? fvars)
(quasisyntax/loc stx (#,make-CLOSURE))
(quasisyntax/loc stx (#,make-CLOSURE (lambda () (values #,@fvars)))))
(append be-defs new-defs))))))]
[(if te ce ae)
(let-values ([(es defs) (defun* (syntax->list #'(te ce ae)))])
(values (quasisyntax/loc stx (if #,@es))
defs))]
[(quote datum)
(values stx
empty)]
[(quote-syntax datum)
(values stx
empty)]
[(with-continuation-mark ke me be)
(let-values ([(es defs) (defun* (list #'ke #'me #'be))])
(values (quasisyntax/loc stx (with-continuation-mark #,@es))
defs))]
[(#%plain-app e ...)
(let-values ([(es defs) (defun* (syntax->list #'(e ...)))])
(values (quasisyntax/loc stx (#%plain-app #,@es))
defs))]
[(#%top . v)
(values stx
empty)]
[(#%variable-reference . v)
(values stx
empty)]
[id (identifier? #'id)
(values stx
empty)]
; XXX Shouldn't
[(letrec-syntaxes+values ([(sv ...) se] ...)
([(vv ...) ve] ...)
be ...)
(let-values ([(nses se-defs) (defun* (syntax->list #'(se ...)))]
[(nves ve-defs) (defun* (syntax->list #'(ve ...)))]
[(nbes be-defs) (defun* (syntax->list #'(be ...)))])
(with-syntax ([(nse ...) nses]
[(nve ...) nves]
[(nbe ...) nbes])
(values (syntax/loc stx
(letrec-syntaxes+values ([(sv ...) nse] ...)
([(vv ...) nve] ...)
nbe ...))
(append se-defs ve-defs be-defs))))]
[(#%expression d)
(let-values ([(nd d-defs) (defun #'d)])
(values (quasisyntax/loc stx (#%expression #,nd))
d-defs))]
[_
(raise-syntax-error 'defun "Dropped through:" stx)]))))
; lift defun to list of syntaxes
(define (lift-defun defun)
(lambda (stxs)
(match
(foldl (lambda (stx acc)
(let-values ([(nstx stx-defs) (defun stx)])
(match acc
[(list-rest nstxs defs)
(cons (list* nstx nstxs)
(append stx-defs defs))])))
(cons empty empty)
stxs)
[(list-rest nstxs defs)
(values (reverse nstxs)
defs)])))
(define defun* (lift-defun defun))
(define defun** (lift-defun (lambda (stx) (defun* (syntax->list stx)))))