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authorAndy Wingo <wingo@pobox.com>2009-10-25 13:19:11 +0100
committerAndy Wingo <wingo@pobox.com>2009-10-25 13:19:11 +0100
commit9a8eb5fb4641bd9ea83903624c8c71192fe0d0f6 (patch)
tree1ba3fcdc7eba9f7840fe2c5039a6d94d5bb2e4f2 /module/srfi/srfi-16.scm
parent647117cd3599c1eaae5afe4b77fa15886d6d344d (diff)
downloadguile-9a8eb5fb4641bd9ea83903624c8c71192fe0d0f6.tar.gz
srfi-16 just re-exports psyntax's case-lambda
* module/srfi/srfi-16.scm (case-lambda): Just re-export the core's case-lambda, it's semantically the same but faster and better integrated.
Diffstat (limited to 'module/srfi/srfi-16.scm')
-rw-r--r--module/srfi/srfi-16.scm79
1 files changed, 3 insertions, 76 deletions
diff --git a/module/srfi/srfi-16.scm b/module/srfi/srfi-16.scm
index 36abee613..caec784ba 100644
--- a/module/srfi/srfi-16.scm
+++ b/module/srfi/srfi-16.scm
@@ -46,81 +46,8 @@
;;; Code:
(define-module (srfi srfi-16)
- #:replace (case-lambda))
+ #:re-export (case-lambda))
-(cond-expand-provide (current-module) '(srfi-16))
-
-(define-macro (case-lambda . clauses)
-
- ;; Return the length of the list @var{l}, but allow dotted list.
- ;;
- (define (alength l)
- (cond ((null? l) 0)
- ((pair? l) (+ 1 (alength (cdr l))))
- (else 0)))
-
- ;; Return @code{#t} if @var{l} is a dotted list, @code{#f} if it is
- ;; a normal list.
- ;;
- (define (dotted? l)
- (cond ((null? l) #f)
- ((pair? l) (dotted? (cdr l)))
- (else #t)))
-
- ;; Return the expression for accessing the @var{index}th element of
- ;; the list called @var{args-name}. If @var{tail?} is true, code
- ;; for accessing the list-tail is generated, otherwise for accessing
- ;; the list element itself.
- ;;
- (define (accessor args-name index tail?)
- (if tail?
- (case index
- ((0) `,args-name)
- ((1) `(cdr ,args-name))
- ((2) `(cddr ,args-name))
- ((3) `(cdddr ,args-name))
- ((4) `(cddddr ,args-name))
- (else `(list-tail ,args-name ,index)))
- (case index
- ((0) `(car ,args-name))
- ((1) `(cadr ,args-name))
- ((2) `(caddr ,args-name))
- ((3) `(cadddr ,args-name))
- (else `(list-ref ,args-name ,index)))))
+;; Case-lambda is now provided by code psyntax.
- ;; Generate the binding lists of the variables of one case-lambda
- ;; clause. @var{vars} is the (possibly dotted) list of variables
- ;; and @var{args-name} is the generated name used for the argument
- ;; list.
- ;;
- (define (gen-temps vars args-name)
- (let lp ((v vars) (i 0))
- (cond ((null? v) '())
- ((pair? v)
- (cons `(,(car v) ,(accessor args-name i #f))
- (lp (cdr v) (+ i 1))))
- (else `((,v ,(accessor args-name i #t)))))))
-
- ;; Generate the cond clauses for each of the clauses of case-lambda,
- ;; including the parameter count check, binding of the parameters
- ;; and the code of the corresponding body.
- ;;
- (define (gen-clauses l length-name args-name)
- (cond ((null? l) (list '(else (error "too few arguments"))))
- (else
- (cons
- `((,(if (dotted? (caar l)) '>= '=)
- ,length-name ,(alength (caar l)))
- (let ,(gen-temps (caar l) args-name)
- ,@(cdar l)))
- (gen-clauses (cdr l) length-name args-name)))))
-
- (let ((args-name (gensym))
- (length-name (gensym)))
- (let ((proc
- `(lambda ,args-name
- (let ((,length-name (length ,args-name)))
- (cond ,@(gen-clauses clauses length-name args-name))))))
- proc)))
-
-;;; srfi-16.scm ends here
+(cond-expand-provide (current-module) '(srfi-16))