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syntax-case equivalent to syntax-rules
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From: |
Damien Mattei |
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Subject: |
syntax-case equivalent to syntax-rules |
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Date: |
Sun, 29 Aug 2021 13:29:19 +0200 |
hello,
i write a macro that needs both the features of syntax-rules and
syntax-case based on documentation:
https://www.gnu.org/software/guile/manual/html_node/Syntax-Case.html
i have :
;; scheme@(guile-user)> (def (foo) (when #t (return "hello") "bye"))
;; scheme@(guile-user)> (foo)
;; "hello"
;; (def x)
;; TODO: study def of a recursive function
(define-syntax def
(lambda (stx)
(syntax-case stx (declare)
;; definition without a value assigned
;; (def x)
((_ var) #`(define var '()))
;; (def x 7)
((_ var expr) #`(define var expr))
;; added body body*
;;((_ (declare var1) <body> <body>* ...) #`(letrec ((var1 '())) <body>
<body>* ...))
;; 'compiles' but do not have the expected behavior:
((_ (declare var1 ...) <body> ...) #`(letrec ((var1 '()) ...)
<body> ...))
;; (def (foo) (when #t (return "hello") "bye"))
((_ (<name> <arg> ...) <body> <body>* ...)
(let ((ret-id (datum->syntax stx 'return)))
#`(define (<name> <arg> ...)
(call/cc (lambda (#,ret-id) <body> <body>* ...))))))))
and def2 that have the good behavior:
scheme@(guile-user)> (def2 (declare x y z) (list x y z))
$1 = (() () ())
(define-syntax def2
(syntax-rules (declare)
((_ (declare var1 ...) <body> ...) (letrec ((var1 '()) ...)
<body> ...))))
i want to merge def and def2 in a single macro
any solution?
Damien
- syntax-case equivalent to syntax-rules,
Damien Mattei <=