42 lines
1.3 KiB
Scheme
42 lines
1.3 KiB
Scheme
; Copied from Lars T Hansen's SRFI document.
|
|
|
|
(define-syntax case-lambda
|
|
(syntax-rules ()
|
|
((case-lambda
|
|
(?a1 ?e1 ...)
|
|
?clause1 ...)
|
|
(lambda args
|
|
(let ((l (length args)))
|
|
(case-lambda "CLAUSE" args l
|
|
(?a1 ?e1 ...)
|
|
?clause1 ...))))
|
|
((case-lambda "CLAUSE" ?args ?l
|
|
((?a1 ...) ?e1 ...)
|
|
?clause1 ...)
|
|
(if (= ?l (length '(?a1 ...)))
|
|
(apply (lambda (?a1 ...) ?e1 ...) ?args)
|
|
(case-lambda "CLAUSE" ?args ?l
|
|
?clause1 ...)))
|
|
((case-lambda "CLAUSE" ?args ?l
|
|
((?a1 . ?ar) ?e1 ...)
|
|
?clause1 ...)
|
|
(case-lambda "IMPROPER" ?args ?l 1 (?a1 . ?ar) (?ar ?e1 ...)
|
|
?clause1 ...))
|
|
((case-lambda "CLAUSE" ?args ?l
|
|
(?a1 ?e1 ...)
|
|
?clause1 ...)
|
|
(let ((?a1 ?args))
|
|
?e1 ...))
|
|
((case-lambda "CLAUSE" ?args ?l)
|
|
(error "Wrong number of arguments to CASE-LAMBDA."))
|
|
((case-lambda "IMPROPER" ?args ?l ?k ?al ((?a1 . ?ar) ?e1 ...)
|
|
?clause1 ...)
|
|
(case-lambda "IMPROPER" ?args ?l (+ ?k 1) ?al (?ar ?e1 ...)
|
|
?clause1 ...))
|
|
((case-lambda "IMPROPER" ?args ?l ?k ?al (?ar ?e1 ...)
|
|
?clause1 ...)
|
|
(if (>= ?l ?k)
|
|
(apply (lambda ?al ?e1 ...) ?args)
|
|
(case-lambda "CLAUSE" ?args ?l
|
|
?clause1 ...)))))
|