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fd1517d8 KR |
1 | ;;; srfi-26.scm --- specializing parameters without currying. |
2 | ||
3 | ;; Copyright (C) 2002 Free Software Foundation, Inc. | |
4 | ;; | |
5 | ;; This library is free software; you can redistribute it and/or | |
6 | ;; modify it under the terms of the GNU Lesser General Public | |
7 | ;; License as published by the Free Software Foundation; either | |
8 | ;; version 2.1 of the License, or (at your option) any later version. | |
9 | ;; | |
10 | ;; This library is distributed in the hope that it will be useful, | |
11 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | ;; Lesser General Public License for more details. | |
14 | ;; | |
15 | ;; You should have received a copy of the GNU Lesser General Public | |
16 | ;; License along with this library; if not, write to the Free Software | |
92205699 | 17 | ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
fd1517d8 | 18 | |
feeef4fb MV |
19 | (define-module (srfi srfi-26) |
20 | :export (cut cute)) | |
21 | ||
22 | (cond-expand-provide (current-module) '(srfi-26)) | |
23 | ||
24 | (define-macro (cut slot . slots) | |
25 | (let loop ((slots (cons slot slots)) | |
26 | (params '()) | |
27 | (args '())) | |
28 | (if (null? slots) | |
29 | `(lambda ,(reverse! params) ,(reverse! args)) | |
30 | (let ((s (car slots)) | |
31 | (rest (cdr slots))) | |
32 | (case s | |
33 | ((<>) | |
34 | (let ((var (gensym))) | |
35 | (loop rest (cons var params) (cons var args)))) | |
36 | ((<...>) | |
37 | (if (pair? rest) | |
38 | (error "<...> not on the end of cut expression")) | |
39 | (let ((var (gensym))) | |
40 | `(lambda ,(append! (reverse! params) var) | |
41 | (apply ,@(reverse! (cons var args)))))) | |
42 | (else | |
43 | (loop rest params (cons s args)))))))) | |
44 | ||
45 | (define-macro (cute . slots) | |
46 | (let ((temp (map (lambda (s) (and (not (memq s '(<> <...>))) (gensym))) | |
47 | slots))) | |
48 | `(let ,(delq! #f (map (lambda (t s) (and t (list t s))) temp slots)) | |
49 | (cut ,@(map (lambda (t s) (or t s)) temp slots))))) |