1 | ;;; alist.el --- utility functions for association list |
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2 | |
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3 | ;; Copyright (C) 1993,1994,1995,1996,1998,2000 Free Software Foundation, Inc. |
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4 | |
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5 | ;; Author: MORIOKA Tomohiko <tomo@m17n.org> |
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6 | ;; Keywords: alist |
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7 | |
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8 | ;; This file is part of GNU Emacs. |
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9 | |
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10 | ;; This program is free software; you can redistribute it and/or |
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11 | ;; modify it under the terms of the GNU General Public License as |
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12 | ;; published by the Free Software Foundation; either version 2, or (at |
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13 | ;; your option) any later version. |
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14 | |
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15 | ;; This program is distributed in the hope that it will be useful, but |
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16 | ;; WITHOUT ANY WARRANTY; without even the implied warranty of |
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17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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18 | ;; General Public License for more details. |
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19 | |
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20 | ;; You should have received a copy of the GNU General Public License |
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21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
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22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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23 | ;; Boston, MA 02111-1307, USA. |
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24 | |
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25 | ;;; Code: |
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26 | |
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27 | ;;;###autoload |
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28 | (defun put-alist (key value alist) |
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29 | "Set cdr of an element (KEY . ...) in ALIST to VALUE and return ALIST. |
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30 | If there is no such element, create a new pair (KEY . VALUE) and |
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31 | return a new alist whose car is the new pair and cdr is ALIST." |
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32 | (let ((elm (assoc key alist))) |
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33 | (if elm |
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34 | (progn |
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35 | (setcdr elm value) |
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36 | alist) |
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37 | (cons (cons key value) alist)))) |
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38 | |
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39 | ;;;###autoload |
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40 | (defun del-alist (key alist) |
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41 | "Delete an element whose car equals KEY from ALIST. |
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42 | Return the modified ALIST." |
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43 | (let ((pair (assoc key alist))) |
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44 | (if pair |
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45 | (delq pair alist) |
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46 | alist))) |
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47 | |
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48 | ;;;###autoload |
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49 | (defun set-alist (symbol key value) |
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50 | "Set cdr of an element (KEY . ...) in the alist bound to SYMBOL to VALUE." |
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51 | (or (boundp symbol) |
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52 | (set symbol nil)) |
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53 | (set symbol (put-alist key value (symbol-value symbol)))) |
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54 | |
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55 | ;;;###autoload |
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56 | (defun remove-alist (symbol key) |
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57 | "Delete an element whose car equals KEY from the alist bound to SYMBOL." |
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58 | (and (boundp symbol) |
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59 | (set symbol (del-alist key (symbol-value symbol))))) |
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60 | |
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61 | ;;;###autoload |
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62 | (defun modify-alist (modifier default) |
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63 | "Store elements in the alist MODIFIER in the alist DEFAULT. |
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64 | Return the modified alist." |
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65 | (mapcar (function |
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66 | (lambda (as) |
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67 | (setq default (put-alist (car as)(cdr as) default)))) |
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68 | modifier) |
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69 | default) |
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70 | |
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71 | ;;;###autoload |
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72 | (defun set-modified-alist (symbol modifier) |
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73 | "Store elements in the alist MODIFIER in an alist bound to SYMBOL. |
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74 | If SYMBOL is not bound, set it to nil at first." |
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75 | (if (not (boundp symbol)) |
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76 | (set symbol nil)) |
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77 | (set symbol (modify-alist modifier (eval symbol)))) |
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78 | |
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79 | |
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80 | ;;; @ association-vector-list |
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81 | ;;; |
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82 | |
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83 | ;;;###autoload |
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84 | (defun vassoc (key avlist) |
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85 | "Search AVLIST for an element whose first element equals KEY. |
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86 | AVLIST is a list of vectors. |
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87 | See also `assoc'." |
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88 | (while (and avlist |
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89 | (not (equal key (aref (car avlist) 0)))) |
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90 | (setq avlist (cdr avlist))) |
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91 | (and avlist |
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92 | (car avlist))) |
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93 | |
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94 | |
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95 | ;;; @ end |
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96 | ;;; |
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97 | |
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98 | (require 'product) |
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99 | (product-provide (provide 'alist) (require 'apel-ver)) |
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100 | |
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101 | ;;; alist.el ends here |
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