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special case for delimiters

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svn: r17114
This commit is contained in:
Jon Rafkind 2009-11-30 19:08:55 +00:00
parent 5b3fa4c120
commit ef194eb948
2 changed files with 24 additions and 3 deletions
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2
collects/honu/private/honu.ss
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@ -126,7 +126,7 @@
(let ([v (syntax-local-value (stx-car first) (lambda () #f))])
(and (honu-transformer? v) v))]
[else #f]))))
(printf "~a bound transformer? ~a\n" stx (bound-transformer stx))
;; (printf "~a bound transformer? ~a\n" stx (bound-transformer stx))
(or (bound-transformer stx)
(special-transformer stx)))

25
collects/honu/private/macro.ss
View File

@ -153,7 +153,8 @@
#'rest))])
))
(define-for-syntax (delimiter? x) #f)
(define-for-syntax (delimiter? x)
(or (free-identifier=? x #'\;)))
(define-syntax (my-ellipses stx) (raise-syntax-error 'my-ellipses "dont use this"))
;; (define-syntax (wrapped stx) (raise-syntax-error 'wrapped "dont use wrap"))
@ -166,6 +167,8 @@
(define (reverse-syntax stx)
(with-syntax ([(x ...) (reverse (syntax->list stx))])
#'(x ...)))
(define-syntax-class delimiter-class
(pattern x:id #:when (delimiter? #'x)))
(define-syntax-class ellipses-class
(pattern x:id #:when (free-identifier=? #'x #'(... ...))))
;; use this if you are defining your own ellipses identifier
@ -180,6 +183,19 @@
;; (printf "stx is ~a\n" stx)
;; (printf "... = ~a\n" (free-identifier=? #'(... ...) (stx-car stx)))
(syntax-parse stx
[(ellipses1:ellipses-class ellipses:ellipses-class ... delimiter:delimiter-class x ...)
(with-syntax ([(x* ...) (reverse-syntax (pull #'(delimiter x ...)))])
(reverse-syntax
(with-syntax ([wrapped #'wrapped]
[original
(with-syntax ([(ellipses* ...) (map (lambda (_)
#'((... ...) (... ...)))
(syntax->list #'(ellipses1 ellipses ...)))]
[(x-new ...) (generate-temporaries #'(delimiter x ...))])
(reverse-syntax #'(ellipses* ... x-new ...)))]
#;
[original (syntax->datum (reverse-syntax #'(ellipses1 ellipses ... x ...)))])
#'(ellipses1 ellipses ... (wrapped x* ...) unwrap))))]
[(ellipses1:ellipses-class ellipses:ellipses-class ... x ...)
(with-syntax ([(x* ...) (reverse-syntax (pull #'(x ...)))])
(reverse-syntax
@ -196,13 +212,18 @@
[(x ...) (with-syntax ([(x* ...) (map pull (syntax->list #'(x ...)))])
(reverse-syntax #'(x* ...)))]))))
(begin-for-syntax (trace pull))
;; (begin-for-syntax (trace pull))
(define-for-syntax (unpull stx)
(define-syntax-class ellipses-class
(pattern x:id #:when (free-identifier=? #'x #'(... ...))))
(define-syntax-class delimiter-class
(pattern x:id #:when (delimiter? #'x)))
(syntax-parse stx
#:literals (wrapped unwrap)
[(unwrap (wrapped x ... delimiter:delimiter-class) ...)
(with-syntax ([(x1 ...) (apply append (map syntax->list (syntax->list #'((x ... delimiter) ...))))])
#'(x1 ...))]
[(unwrap (wrapped x ... y) ...)
(with-syntax ([(x1 ...) (car (syntax->list #'((x ...) ...)))])
(with-syntax ([(x1* ...) (map unpull (syntax->list #'(x1 ...)))]