calist.el

   1 ;;; calist.el --- Condition functions
   2
   3 ;; Copyright (C) 1998 MORIOKA Tomohiko.
   4
   5 ;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
   6 ;; Keywords: condition, alist, tree
   7
   8 ;; This file is part of APEL (A Portable Emacs Library).
   9
  10 ;; This program is free software; you can redistribute it and/or
  11 ;; modify it under the terms of the GNU General Public License as
  12 ;; published by the Free Software Foundation; either version 2, or (at
  13 ;; your option) any later version.
  14
  15 ;; This program is distributed in the hope that it will be useful, but
  16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 ;; General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28
  29 (defvar calist-field-match-method-obarray [nil])
  30
  31 (defun define-calist-field-match-method (field-type function)
  32   "Set field-match-method for FIELD-TYPE to FUNCTION."
  33   (fset (intern (symbol-name field-type) calist-field-match-method-obarray)
  34         function))
  35
  36 (defun calist-default-field-match-method (calist field-type field-value)
  37   (let ((s-field (assoc field-type calist)))
  38     (cond ((null s-field)
  39            (cons (cons field-type field-value) calist)
  40            )
  41           ((eq field-value t)
  42            calist)
  43           ((equal (cdr s-field) field-value)
  44            calist))))
  45
  46 (defsubst calist-field-match-method (field-type)
  47   (condition-case nil
  48       (symbol-function
  49        (intern-soft
  50         (symbol-name field-type) calist-field-match-method-obarray))
  51     (error (symbol-function 'calist-default-field-match-method))
  52     ))
  53
  54 (defsubst calist-field-match (calist field-type field-value)
  55   (funcall (calist-field-match-method field-type)
  56            calist field-type field-value))
  57
  58 (defun ctree-match-calist (rule-tree alist)
  59   "Return matched condition-alist if ALIST matches RULE-TREE."
  60   (if (null rule-tree)
  61       alist
  62     (let ((type (car rule-tree))
  63           (choices (cdr rule-tree))
  64           default)
  65       (catch 'tag
  66         (while choices
  67           (let* ((choice (car choices))
  68                  (choice-value (car choice)))
  69             (if (eq choice-value t)
  70                 (setq default choice)
  71               (let ((ret-alist (calist-field-match alist type (car choice))))
  72                 (if ret-alist
  73                     (throw 'tag
  74                            (if (cdr choice)
  75                                (ctree-match-calist (cdr choice) ret-alist)
  76                              ret-alist))
  77                   ))))
  78           (setq choices (cdr choices)))
  79         (if default
  80             (let ((ret-alist (calist-field-match alist type t)))
  81               (if ret-alist
  82                   (if (cdr default)
  83                       (ctree-match-calist (cdr default) ret-alist)
  84                     ret-alist))))
  85         ))))
  86
  87 (defun ctree-find-calist (rule-tree alist &optional all)
  88   "Return list of condition-alist which matches ALIST in RULE-TREE."
  89   (if (null rule-tree)
  90       (list alist)
  91     (let ((type (car rule-tree))
  92           (choices (cdr rule-tree))
  93           default dest)
  94       (while choices
  95         (let* ((choice (car choices))
  96                (choice-value (car choice)))
  97           (if (eq choice-value t)
  98               (setq default choice)
  99             (let ((ret-alist (calist-field-match alist type (car choice))))
 100               (if ret-alist
 101                   (if (cdr choice)
 102                       (setq dest
 103                             (append (ctree-find-calist
 104                                      (cdr choice) ret-alist all)
 105                                     dest))
 106                     (setq dest (cons ret-alist dest))
 107                     )))))
 108         (setq choices (cdr choices)))
 109       (or (and (not all) dest)
 110           (if default
 111               (let ((ret-alist (calist-field-match alist type t)))
 112                 (if ret-alist
 113                     (if (cdr default)
 114                         (setq dest
 115                               (append (ctree-find-calist
 116                                        (cdr default) ret-alist all)
 117                                       dest))
 118                       (setq dest (cons ret-alist dest))
 119                       ))))
 120           )
 121       dest)))
 122
 123 (defun calist-to-ctree (calist)
 124   "Convert condition-alist CALIST to condition-tree."
 125   (if calist
 126       (let* ((cell (car calist)))
 127         (cons (car cell)
 128               (list (cons (cdr cell)
 129                           (calist-to-ctree (cdr calist))
 130                           ))))))
 131
 132 (defun ctree-add-calist-strictly (ctree calist)
 133   "Add condition CALIST to condition-tree CTREE without default clause."
 134   (cond ((null calist) ctree)
 135         ((null ctree)
 136          (calist-to-ctree calist)
 137          )
 138         (t
 139          (let* ((type (car ctree))
 140                 (values (cdr ctree))
 141                 (ret (assoc type calist)))
 142            (if ret
 143                (catch 'tag
 144                  (while values
 145                    (let ((cell (car values)))
 146                      (if (equal (car cell)(cdr ret))
 147                          (throw 'tag
 148                                 (setcdr cell
 149                                         (ctree-add-calist-strictly
 150                                          (cdr cell)
 151                                          (delete ret (copy-alist calist)))
 152                                         ))))
 153                    (setq values (cdr values)))
 154                  (setcdr ctree (cons (cons (cdr ret)
 155                                            (calist-to-ctree
 156                                             (delete ret (copy-alist calist))))
 157                                      (cdr ctree)))
 158                  )
 159              (catch 'tag
 160                (while values
 161                  (let ((cell (car values)))
 162                    (setcdr cell
 163                            (ctree-add-calist-strictly (cdr cell) calist))
 164                    )
 165                  (setq values (cdr values))))
 166              )
 167            ctree))))
 168
 169 (defun ctree-add-calist-with-default (ctree calist)
 170   "Add condition CALIST to condition-tree CTREE with default clause."
 171   (cond ((null calist) ctree)
 172         ((null ctree)
 173          (let* ((cell (car calist))
 174                 (type (car cell))
 175                 (value (cdr cell)))
 176            (cons type
 177                  (list '(t)
 178                        (cons value (calist-to-ctree (cdr calist)))))
 179            ))
 180         (t
 181          (let* ((type (car ctree))
 182                 (values (cdr ctree))
 183                 (ret (assoc type calist)))
 184            (if ret
 185                (catch 'tag
 186                  (while values
 187                    (let ((cell (car values)))
 188                      (if (equal (car cell)(cdr ret))
 189                          (throw 'tag
 190                                 (setcdr cell
 191                                         (ctree-add-calist-with-default
 192                                          (cdr cell)
 193                                          (delete ret (copy-alist calist)))
 194                                         ))))
 195                    (setq values (cdr values)))
 196                  (setcdr ctree (list* '(t)
 197                                       (cons (cdr ret)
 198                                             (calist-to-ctree
 199                                              (delete ret (copy-alist calist))))
 200                                       (cdr ctree)))
 201                  )
 202              (catch 'tag
 203                (while values
 204                  (let ((cell (car values)))
 205                    (setcdr cell
 206                            (ctree-add-calist-with-default (cdr cell) calist))
 207                    )
 208                  (setq values (cdr values)))
 209                (let ((elt (cons t (calist-to-ctree calist))))
 210                  (or (member elt (cdr ctree))
 211                      (setcdr ctree (cons elt (cdr ctree)))
 212                      )))
 213              )
 214            ctree))))
 215
 216 (defun ctree-set-calist-strictly (ctree-var calist)
 217   "Set condition CALIST in CTREE-VAR without default clause."
 218   (set ctree-var
 219        (ctree-add-calist-strictly (symbol-value ctree-var) calist)))
 220
 221 (defun ctree-set-calist-with-default (ctree-var calist)
 222   "Set condition CALIST to CTREE-VAR with default clause."
 223   (set ctree-var
 224        (ctree-add-calist-with-default (symbol-value ctree-var) calist)))
 225
 226
 227 ;;; @ end
 228 ;;;
 229
 230 (provide 'calist)
 231
 232 ;;; calist.el ends here