lisp/emacs-lisp/cl-compat.el

   1 ;;; cl-compat.el --- Common Lisp extensions for GNU Emacs Lisp (compatibility)
   2
   3 ;; Copyright (C) 1993, 2001, 2002, 2003, 2004, 2005,
   4 ;;   2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   5
   6 ;; Author: Dave Gillespie <daveg@synaptics.com>
   7 ;; Version: 2.02
   8 ;; Keywords: extensions
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; These are extensions to Emacs Lisp that provide a degree of
  28 ;; Common Lisp compatibility, beyond what is already built-in
  29 ;; in Emacs Lisp.
  30 ;;
  31 ;; This package was written by Dave Gillespie; it is a complete
  32 ;; rewrite of Cesar Quiroz's original cl.el package of December 1986.
  33 ;;
  34 ;; This package works with Emacs 18, Emacs 19, and Lucid Emacs 19.
  35 ;;
  36 ;; Bug reports, comments, and suggestions are welcome!
  37
  38 ;; This file contains emulations of internal routines of the older
  39 ;; CL package which users may have called directly from their code.
  40 ;; Use (require 'cl-compat) to get these routines.
  41
  42 ;; See cl.el for Change Log.
  43
  44
  45 ;;; Code:
  46
  47 ;; This used to be:
  48 ;; (or (featurep 'cl) (require 'cl))
  49 ;; which just has the effect of fooling the byte-compiler into not
  50 ;; loading cl when compiling.  However, that leads to some bogus
  51 ;; compiler warnings.  Loading cl when compiling cannot do any harm,
  52 ;; because for a long time bootstrap-emacs contained 'cl, due to being
  53 ;; dumped from uncompiled files that eval-when-compile'd cl.  So every
  54 ;; file was compiled with 'cl loaded.
  55 (require 'cl)
  56
  57
  58 ;;; Keyword routines not supported by new package.
  59
  60 (defmacro defkeyword (x &optional doc)
  61   (list* 'defconst x (list 'quote x) (and doc (list doc))))
  62
  63 (defun keyword-of (sym)
  64   (or (keywordp sym) (keywordp (intern (format ":%s" sym)))))
  65
  66
  67 ;;; Multiple values.  Note that the new package uses a different
  68 ;;; convention for multiple values.  The following definitions
  69 ;;; emulate the old convention; all function names have been changed
  70 ;;; by capitalizing the first letter: Values, Multiple-value-*,
  71 ;;; to avoid conflict with the new-style definitions in cl-macs.
  72
  73 (put 'Multiple-value-bind  'lisp-indent-function 2)
  74 (put 'Multiple-value-setq  'lisp-indent-function 2)
  75 (put 'Multiple-value-call  'lisp-indent-function 1)
  76 (put 'Multiple-value-prog1 'lisp-indent-function 1)
  77
  78 (defvar *mvalues-values* nil)
  79
  80 (defun Values (&rest val-forms)
  81   (setq *mvalues-values* val-forms)
  82   (car val-forms))
  83
  84 (defun Values-list (val-forms)
  85   (apply 'values val-forms))
  86
  87 (defmacro Multiple-value-list (form)
  88   (list 'let* (list '(*mvalues-values* nil) (list '*mvalues-temp* form))
  89         '(or (and (eq *mvalues-temp* (car *mvalues-values*)) *mvalues-values*)
  90              (list *mvalues-temp*))))
  91
  92 (defmacro Multiple-value-call (function &rest args)
  93   (list 'apply function
  94         (cons 'append
  95               (mapcar (function (lambda (x) (list 'Multiple-value-list x)))
  96                       args))))
  97
  98 (defmacro Multiple-value-bind (vars form &rest body)
  99   (list* 'multiple-value-bind vars (list 'Multiple-value-list form) body))
 100
 101 (defmacro Multiple-value-setq (vars form)
 102   (list 'multiple-value-setq vars (list 'Multiple-value-list form)))
 103
 104 (defmacro Multiple-value-prog1 (form &rest body)
 105   (list 'prog1 form (list* 'let '((*mvalues-values* nil)) body)))
 106
 107
 108 ;;; Routines for parsing keyword arguments.
 109
 110 (defun build-klist (arglist keys &optional allow-others)
 111   (let ((res (Multiple-value-call 'mapcar* 'cons (unzip-lists arglist))))
 112     (or allow-others
 113         (let ((bad (set-difference (mapcar 'car res) keys)))
 114           (if bad (error "Bad keywords: %s not in %s" bad keys))))
 115     res))
 116
 117 (defun extract-from-klist (klist key &optional def)
 118   (let ((res (assq key klist))) (if res (cdr res) def)))
 119
 120 (defun keyword-argument-supplied-p (klist key)
 121   (assq key klist))
 122
 123 (defun elt-satisfies-test-p (item elt klist)
 124   (let ((test-not (cdr (assq ':test-not klist)))
 125         (test (cdr (assq ':test klist)))
 126         (key (cdr (assq ':key klist))))
 127     (if key (setq elt (funcall key elt)))
 128     (if test-not (not (funcall test-not item elt))
 129       (funcall (or test 'eql) item elt))))
 130
 131
 132 ;;; Rounding functions with old-style multiple value returns.
 133
 134 (defun cl-floor (a &optional b) (Values-list (floor* a b)))
 135 (defun cl-ceiling (a &optional b) (Values-list (ceiling* a b)))
 136 (defun cl-round (a &optional b) (Values-list (round* a b)))
 137 (defun cl-truncate (a &optional b) (Values-list (truncate* a b)))
 138
 139 (defun safe-idiv (a b)
 140   (let* ((q (/ (abs a) (abs b)))
 141          (s (* (signum a) (signum b))))
 142     (Values q (- a (* s q b)) s)))
 143
 144
 145 ;; Internal routines.
 146
 147 (defun pair-with-newsyms (oldforms)
 148   (let ((newsyms (mapcar (lambda (x) (make-symbol "--cl-var--")) oldforms)))
 149     (Values (mapcar* 'list newsyms oldforms) newsyms)))
 150
 151 (defun zip-lists (evens odds)
 152   (mapcan 'list evens odds))
 153
 154 (defun unzip-lists (list)
 155   (let ((e nil) (o nil))
 156     (while list
 157       (setq e (cons (car list) e) o (cons (cadr list) o) list (cddr list)))
 158     (Values (nreverse e) (nreverse o))))
 159
 160 (defun reassemble-argslists (list)
 161   (let ((n (apply 'min (mapcar 'length list))) (res nil))
 162     (while (>= (setq n (1- n)) 0)
 163       (setq res (cons (mapcar (function (lambda (x) (elt x n))) list) res)))
 164     res))
 165
 166 (defun duplicate-symbols-p (list)
 167   (let ((res nil))
 168     (while list
 169       (if (memq (car list) (cdr list)) (setq res (cons (car list) res)))
 170       (setq list (cdr list)))
 171     res))
 172
 173
 174 ;;; Setf internals.
 175
 176 (defun setnth (n list x)
 177   (setcar (nthcdr n list) x))
 178
 179 (defun setnthcdr (n list x)
 180   (setcdr (nthcdr (1- n) list) x))
 181
 182 (defun setelt (seq n x)
 183   (if (consp seq) (setcar (nthcdr n seq) x) (aset seq n x)))
 184
 185
 186 ;;; Functions omitted: case-clausify, check-do-stepforms, check-do-endforms,
 187 ;;; extract-do-inits, extract-do[*]-steps, select-stepping-forms,
 188 ;;; elt-satisfies-if[-not]-p, with-keyword-args, mv-bind-clausify,
 189 ;;; all names with embedded `$'.
 190
 191
 192 (provide 'cl-compat)
 193
 194 ;; Local variables:
 195 ;; byte-compile-warnings: (not cl-functions)
 196 ;; End:
 197
 198 ;; arch-tag: 9996bb4f-aaf5-4592-b436-bf64759a3163
 199 ;;; cl-compat.el ends here