| 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 |
| 17 | ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 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))))) |