gcc/ada/a-strmap.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUNTIME COMPONENTS                          --
   4 --                                                                          --
   5 --                     A D A . S T R I N G S . M A P S                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  Note: parts of this code are derived from the ADAR.CSH public domain
  35 --  Ada 83 versions of the Appendix C string handling packages. The main
  36 --  differences are that we avoid the use of the minimize function which
  37 --  is bit-by-bit or character-by-character and therefore rather slow.
  38 --  Generally for character sets we favor the full 32-byte representation.
  39
  40 package body Ada.Strings.Maps is
  41
  42    use Ada.Characters.Latin_1;
  43
  44    ---------
  45    -- "-" --
  46    ---------
  47
  48    function "-" (Left, Right : Character_Set) return Character_Set is
  49    begin
  50       return Left and not Right;
  51    end "-";
  52
  53    ---------
  54    -- "=" --
  55    ---------
  56
  57    function "=" (Left, Right : Character_Set) return Boolean is
  58    begin
  59       return Character_Set_Internal (Left) = Character_Set_Internal (Right);
  60    end "=";
  61
  62    -----------
  63    -- "and" --
  64    -----------
  65
  66    function "and" (Left, Right : Character_Set) return Character_Set is
  67    begin
  68       return Character_Set
  69         (Character_Set_Internal (Left) and Character_Set_Internal (Right));
  70    end "and";
  71
  72    -----------
  73    -- "not" --
  74    -----------
  75
  76    function "not" (Right : Character_Set) return Character_Set is
  77    begin
  78       return Character_Set (not Character_Set_Internal (Right));
  79    end "not";
  80
  81    ----------
  82    -- "or" --
  83    ----------
  84
  85    function "or" (Left, Right : Character_Set) return Character_Set is
  86    begin
  87       return Character_Set
  88         (Character_Set_Internal (Left) or Character_Set_Internal (Right));
  89    end "or";
  90
  91    -----------
  92    -- "xor" --
  93    -----------
  94
  95    function "xor" (Left, Right : Character_Set) return Character_Set is
  96    begin
  97       return Character_Set
  98         (Character_Set_Internal (Left) xor Character_Set_Internal (Right));
  99    end "xor";
 100
 101    -----------
 102    -- Is_In --
 103    -----------
 104
 105    function Is_In
 106      (Element : Character;
 107       Set     : Character_Set) return Boolean
 108    is
 109    begin
 110       return Set (Element);
 111    end Is_In;
 112
 113    ---------------
 114    -- Is_Subset --
 115    ---------------
 116
 117    function Is_Subset
 118      (Elements : Character_Set;
 119       Set      : Character_Set) return Boolean
 120    is
 121    begin
 122       return (Elements and Set) = Elements;
 123    end Is_Subset;
 124
 125    ---------------
 126    -- To_Domain --
 127    ---------------
 128
 129    function To_Domain (Map : Character_Mapping) return Character_Sequence
 130    is
 131       Result : String (1 .. Map'Length);
 132       J      : Natural;
 133
 134    begin
 135       J := 0;
 136       for C in Map'Range loop
 137          if Map (C) /= C then
 138             J := J + 1;
 139             Result (J) := C;
 140          end if;
 141       end loop;
 142
 143       return Result (1 .. J);
 144    end To_Domain;
 145
 146    ----------------
 147    -- To_Mapping --
 148    ----------------
 149
 150    function To_Mapping
 151      (From, To : Character_Sequence) return Character_Mapping
 152    is
 153       Result   : Character_Mapping;
 154       Inserted : Character_Set := Null_Set;
 155       From_Len : constant Natural := From'Length;
 156       To_Len   : constant Natural := To'Length;
 157
 158    begin
 159       if From_Len /= To_Len then
 160          raise Strings.Translation_Error;
 161       end if;
 162
 163       for Char in Character loop
 164          Result (Char) := Char;
 165       end loop;
 166
 167       for J in From'Range loop
 168          if Inserted (From (J)) then
 169             raise Strings.Translation_Error;
 170          end if;
 171
 172          Result   (From (J)) := To (J - From'First + To'First);
 173          Inserted (From (J)) := True;
 174       end loop;
 175
 176       return Result;
 177    end To_Mapping;
 178
 179    --------------
 180    -- To_Range --
 181    --------------
 182
 183    function To_Range (Map : Character_Mapping) return Character_Sequence
 184    is
 185       Result : String (1 .. Map'Length);
 186       J      : Natural;
 187    begin
 188       J := 0;
 189       for C in Map'Range loop
 190          if Map (C) /= C then
 191             J := J + 1;
 192             Result (J) := Map (C);
 193          end if;
 194       end loop;
 195
 196       return Result (1 .. J);
 197    end To_Range;
 198
 199    ---------------
 200    -- To_Ranges --
 201    ---------------
 202
 203    function To_Ranges (Set : Character_Set) return Character_Ranges is
 204       Max_Ranges : Character_Ranges (1 .. Set'Length / 2 + 1);
 205       Range_Num  : Natural;
 206       C          : Character;
 207
 208    begin
 209       C := Character'First;
 210       Range_Num := 0;
 211
 212       loop
 213          --  Skip gap between subsets
 214
 215          while not Set (C) loop
 216             exit when C = Character'Last;
 217             C := Character'Succ (C);
 218          end loop;
 219
 220          exit when not Set (C);
 221
 222          Range_Num := Range_Num + 1;
 223          Max_Ranges (Range_Num).Low := C;
 224
 225          --  Span a subset
 226
 227          loop
 228             exit when not Set (C) or else C = Character'Last;
 229             C := Character'Succ (C);
 230          end loop;
 231
 232          if Set (C) then
 233             Max_Ranges (Range_Num). High := C;
 234             exit;
 235          else
 236             Max_Ranges (Range_Num). High := Character'Pred (C);
 237          end if;
 238       end loop;
 239
 240       return Max_Ranges (1 .. Range_Num);
 241    end To_Ranges;
 242
 243    -----------------
 244    -- To_Sequence --
 245    -----------------
 246
 247    function To_Sequence (Set : Character_Set) return Character_Sequence is
 248       Result : String (1 .. Character'Pos (Character'Last) + 1);
 249       Count  : Natural := 0;
 250    begin
 251       for Char in Set'Range loop
 252          if Set (Char) then
 253             Count := Count + 1;
 254             Result (Count) := Char;
 255          end if;
 256       end loop;
 257
 258       return Result (1 .. Count);
 259    end To_Sequence;
 260
 261    ------------
 262    -- To_Set --
 263    ------------
 264
 265    function To_Set (Ranges : Character_Ranges) return Character_Set is
 266       Result : Character_Set;
 267    begin
 268       for C in Result'Range loop
 269          Result (C) := False;
 270       end loop;
 271
 272       for R in Ranges'Range loop
 273          for C in Ranges (R).Low .. Ranges (R).High loop
 274             Result (C) := True;
 275          end loop;
 276       end loop;
 277
 278       return Result;
 279    end To_Set;
 280
 281    function To_Set (Span : Character_Range) return Character_Set is
 282       Result : Character_Set;
 283    begin
 284       for C in Result'Range loop
 285          Result (C) := False;
 286       end loop;
 287
 288       for C in Span.Low .. Span.High loop
 289          Result (C) := True;
 290       end loop;
 291
 292       return Result;
 293    end To_Set;
 294
 295    function To_Set (Sequence : Character_Sequence) return Character_Set is
 296       Result : Character_Set := Null_Set;
 297    begin
 298       for J in Sequence'Range loop
 299          Result (Sequence (J)) := True;
 300       end loop;
 301
 302       return Result;
 303    end To_Set;
 304
 305    function To_Set (Singleton : Character) return Character_Set is
 306       Result : Character_Set := Null_Set;
 307    begin
 308       Result (Singleton) := True;
 309       return Result;
 310    end To_Set;
 311
 312    -----------
 313    -- Value --
 314    -----------
 315
 316    function Value
 317      (Map     : Character_Mapping;
 318       Element : Character) return Character
 319    is
 320    begin
 321       return Map (Element);
 322    end Value;
 323
 324 end Ada.Strings.Maps;