| 1 | /* GNU Emacs routines to deal with case tables. |
| 2 | Copyright (C) 1993 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU Emacs. |
| 5 | |
| 6 | GNU Emacs is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 1, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GNU Emacs is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU Emacs; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | /* Written by Howard Gayle. See chartab.c for details. */ |
| 21 | |
| 22 | #include "config.h" |
| 23 | #include "lisp.h" |
| 24 | #include "buffer.h" |
| 25 | |
| 26 | Lisp_Object Qcase_table_p; |
| 27 | Lisp_Object Vascii_downcase_table, Vascii_upcase_table; |
| 28 | Lisp_Object Vascii_canon_table, Vascii_eqv_table; |
| 29 | |
| 30 | void compute_trt_inverse (); |
| 31 | |
| 32 | DEFUN ("case-table-p", Fcase_table_p, Scase_table_p, 1, 1, 0, |
| 33 | "Return t iff ARG is a case table.\n\ |
| 34 | See `set-case-table' for more information on these data structures.") |
| 35 | (table) |
| 36 | Lisp_Object table; |
| 37 | { |
| 38 | Lisp_Object down, up, canon, eqv; |
| 39 | down = Fcar_safe (table); |
| 40 | up = Fcar_safe (Fcdr_safe (table)); |
| 41 | canon = Fcar_safe (Fcdr_safe (Fcdr_safe (table))); |
| 42 | eqv = Fcar_safe (Fcdr_safe (Fcdr_safe (Fcdr_safe (table)))); |
| 43 | |
| 44 | #define STRING256_P(obj) \ |
| 45 | (XTYPE (obj) == Lisp_String && XSTRING (obj)->size == 256) |
| 46 | |
| 47 | return (STRING256_P (down) |
| 48 | && (NILP (up) || STRING256_P (up)) |
| 49 | && ((NILP (canon) && NILP (eqv)) |
| 50 | || (STRING256_P (canon) && STRING256_P (eqv))) |
| 51 | ? Qt : Qnil); |
| 52 | } |
| 53 | |
| 54 | static Lisp_Object |
| 55 | check_case_table (obj) |
| 56 | Lisp_Object obj; |
| 57 | { |
| 58 | register Lisp_Object tem; |
| 59 | |
| 60 | while (tem = Fcase_table_p (obj), NILP (tem)) |
| 61 | obj = wrong_type_argument (Qcase_table_p, obj); |
| 62 | return (obj); |
| 63 | } |
| 64 | |
| 65 | DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0, |
| 66 | "Return the case table of the current buffer.") |
| 67 | () |
| 68 | { |
| 69 | Lisp_Object down, up, canon, eqv; |
| 70 | |
| 71 | down = current_buffer->downcase_table; |
| 72 | up = current_buffer->upcase_table; |
| 73 | canon = current_buffer->case_canon_table; |
| 74 | eqv = current_buffer->case_eqv_table; |
| 75 | |
| 76 | return Fcons (down, Fcons (up, Fcons (canon, Fcons (eqv, Qnil)))); |
| 77 | } |
| 78 | |
| 79 | DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0, |
| 80 | "Return the standard case table.\n\ |
| 81 | This is the one used for new buffers.") |
| 82 | () |
| 83 | { |
| 84 | return Fcons (Vascii_downcase_table, |
| 85 | Fcons (Vascii_upcase_table, |
| 86 | Fcons (Vascii_canon_table, |
| 87 | Fcons (Vascii_eqv_table, Qnil)))); |
| 88 | } |
| 89 | |
| 90 | static Lisp_Object set_case_table (); |
| 91 | |
| 92 | DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0, |
| 93 | "Select a new case table for the current buffer.\n\ |
| 94 | A case table is a list (DOWNCASE UPCASE CANONICALIZE EQUIVALENCES)\n\ |
| 95 | where each element is either nil or a string of length 256.\n\ |
| 96 | DOWNCASE maps each character to its lower-case equivalent.\n\ |
| 97 | UPCASE maps each character to its upper-case equivalent;\n\ |
| 98 | if lower and upper case characters are in 1-1 correspondence,\n\ |
| 99 | you may use nil and the upcase table will be deduced from DOWNCASE.\n\ |
| 100 | CANONICALIZE maps each character to a canonical equivalent;\n\ |
| 101 | any two characters that are related by case-conversion have the same\n\ |
| 102 | canonical equivalent character.\n\ |
| 103 | EQUIVALENCES is a map that cyclicly permutes each equivalence class\n\ |
| 104 | (of characters with the same canonical equivalent).\n\ |
| 105 | Both CANONICALIZE and EQUIVALENCES may be nil, in which case\n\ |
| 106 | both are deduced from DOWNCASE and UPCASE.") |
| 107 | (table) |
| 108 | Lisp_Object table; |
| 109 | { |
| 110 | return set_case_table (table, 0); |
| 111 | } |
| 112 | |
| 113 | DEFUN ("set-standard-case-table", Fset_standard_case_table, Sset_standard_case_table, 1, 1, 0, |
| 114 | "Select a new standard case table for new buffers.\n\ |
| 115 | See `set-case-table' for more info on case tables.") |
| 116 | (table) |
| 117 | Lisp_Object table; |
| 118 | { |
| 119 | return set_case_table (table, 1); |
| 120 | } |
| 121 | |
| 122 | static Lisp_Object |
| 123 | set_case_table (table, standard) |
| 124 | Lisp_Object table; |
| 125 | int standard; |
| 126 | { |
| 127 | Lisp_Object down, up, canon, eqv; |
| 128 | |
| 129 | check_case_table (table); |
| 130 | |
| 131 | down = Fcar_safe (table); |
| 132 | up = Fcar_safe (Fcdr_safe (table)); |
| 133 | canon = Fcar_safe (Fcdr_safe (Fcdr_safe (table))); |
| 134 | eqv = Fcar_safe (Fcdr_safe (Fcdr_safe (Fcdr_safe (table)))); |
| 135 | |
| 136 | if (NILP (up)) |
| 137 | { |
| 138 | up = Fmake_string (make_number (256), make_number (0)); |
| 139 | compute_trt_inverse (XSTRING (down)->data, XSTRING (up)->data); |
| 140 | } |
| 141 | |
| 142 | if (NILP (canon)) |
| 143 | { |
| 144 | register int i; |
| 145 | unsigned char *upvec = XSTRING (up)->data; |
| 146 | unsigned char *downvec = XSTRING (down)->data; |
| 147 | |
| 148 | canon = Fmake_string (make_number (256), make_number (0)); |
| 149 | eqv = Fmake_string (make_number (256), make_number (0)); |
| 150 | |
| 151 | /* Set up the CANON vector; for each character, |
| 152 | this sequence of upcasing and downcasing ought to |
| 153 | get the "preferred" lowercase equivalent. */ |
| 154 | for (i = 0; i < 256; i++) |
| 155 | XSTRING (canon)->data[i] = downvec[upvec[downvec[i]]]; |
| 156 | |
| 157 | compute_trt_inverse (XSTRING (canon)->data, XSTRING (eqv)->data); |
| 158 | } |
| 159 | |
| 160 | if (standard) |
| 161 | { |
| 162 | Vascii_downcase_table = down; |
| 163 | Vascii_upcase_table = up; |
| 164 | Vascii_canon_table = canon; |
| 165 | Vascii_eqv_table = eqv; |
| 166 | } |
| 167 | else |
| 168 | { |
| 169 | current_buffer->downcase_table = down; |
| 170 | current_buffer->upcase_table = up; |
| 171 | current_buffer->case_canon_table = canon; |
| 172 | current_buffer->case_eqv_table = eqv; |
| 173 | } |
| 174 | return table; |
| 175 | } |
| 176 | \f |
| 177 | /* Given a translate table TRT, store the inverse mapping into INVERSE. |
| 178 | Since TRT is not one-to-one, INVERSE is not a simple mapping. |
| 179 | Instead, it divides the space of characters into equivalence classes. |
| 180 | All characters in a given class form one circular list, chained through |
| 181 | the elements of INVERSE. */ |
| 182 | |
| 183 | void |
| 184 | compute_trt_inverse (trt, inverse) |
| 185 | register unsigned char *trt; |
| 186 | register unsigned char *inverse; |
| 187 | { |
| 188 | register int i = 0400; |
| 189 | register unsigned char c, q; |
| 190 | |
| 191 | while (i--) |
| 192 | inverse[i] = i; |
| 193 | i = 0400; |
| 194 | while (i--) |
| 195 | { |
| 196 | if ((q = trt[i]) != (unsigned char) i) |
| 197 | { |
| 198 | c = inverse[q]; |
| 199 | inverse[q] = i; |
| 200 | inverse[i] = c; |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | \f |
| 205 | init_casetab_once () |
| 206 | { |
| 207 | register int i; |
| 208 | Lisp_Object tem; |
| 209 | |
| 210 | tem = Fmake_string (make_number (256), make_number (0)); |
| 211 | Vascii_downcase_table = tem; |
| 212 | Vascii_canon_table = tem; |
| 213 | |
| 214 | for (i = 0; i < 256; i++) |
| 215 | XSTRING (tem)->data[i] = (i >= 'A' && i <= 'Z') ? i + 040 : i; |
| 216 | |
| 217 | tem = Fmake_string (make_number (256), make_number (0)); |
| 218 | Vascii_upcase_table = tem; |
| 219 | Vascii_eqv_table = tem; |
| 220 | |
| 221 | for (i = 0; i < 256; i++) |
| 222 | XSTRING (tem)->data[i] |
| 223 | = ((i >= 'A' && i <= 'Z') |
| 224 | ? i + ('a' - 'A') |
| 225 | : ((i >= 'a' && i <= 'z') |
| 226 | ? i + ('A' - 'a') |
| 227 | : i)); |
| 228 | } |
| 229 | |
| 230 | syms_of_casetab () |
| 231 | { |
| 232 | Qcase_table_p = intern ("case-table-p"); |
| 233 | staticpro (&Qcase_table_p); |
| 234 | staticpro (&Vascii_downcase_table); |
| 235 | staticpro (&Vascii_upcase_table); |
| 236 | staticpro (&Vascii_canon_table); |
| 237 | staticpro (&Vascii_eqv_table); |
| 238 | |
| 239 | defsubr (&Scase_table_p); |
| 240 | defsubr (&Scurrent_case_table); |
| 241 | defsubr (&Sstandard_case_table); |
| 242 | defsubr (&Sset_case_table); |
| 243 | defsubr (&Sset_standard_case_table); |
| 244 | |
| 245 | #if 0 |
| 246 | DEFVAR_LISP ("ascii-downcase-table", &Vascii_downcase_table, |
| 247 | "String mapping ASCII characters to lowercase equivalents."); |
| 248 | DEFVAR_LISP ("ascii-upcase-table", &Vascii_upcase_table, |
| 249 | "String mapping ASCII characters to uppercase equivalents."); |
| 250 | #endif |
| 251 | } |