File : a-strmap.adb


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME 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) 1992-2009, 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 3,  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.                                     --
  17 --                                                                          --
  18 --                                                                          --
  19 --                                                                          --
  20 --                                                                          --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31 
  32 --  Note: parts of this code are derived from the ADAR.CSH public domain
  33 --  Ada 83 versions of the Appendix C string handling packages. The main
  34 --  differences are that we avoid the use of the minimize function which
  35 --  is bit-by-bit or character-by-character and therefore rather slow.
  36 --  Generally for character sets we favor the full 32-byte representation.
  37 
  38 package body Ada.Strings.Maps is
  39 
  40    use Ada.Characters.Latin_1;
  41 
  42    ---------
  43    -- "-" --
  44    ---------
  45 
  46    function "-" (Left, Right : Character_Set) return Character_Set is
  47    begin
  48       return Left and not Right;
  49    end "-";
  50 
  51    ---------
  52    -- "=" --
  53    ---------
  54 
  55    function "=" (Left, Right : Character_Set) return Boolean is
  56    begin
  57       return Character_Set_Internal (Left) = Character_Set_Internal (Right);
  58    end "=";
  59 
  60    -----------
  61    -- "and" --
  62    -----------
  63 
  64    function "and" (Left, Right : Character_Set) return Character_Set is
  65    begin
  66       return Character_Set
  67         (Character_Set_Internal (Left) and Character_Set_Internal (Right));
  68    end "and";
  69 
  70    -----------
  71    -- "not" --
  72    -----------
  73 
  74    function "not" (Right : Character_Set) return Character_Set is
  75    begin
  76       return Character_Set (not Character_Set_Internal (Right));
  77    end "not";
  78 
  79    ----------
  80    -- "or" --
  81    ----------
  82 
  83    function "or" (Left, Right : Character_Set) return Character_Set is
  84    begin
  85       return Character_Set
  86         (Character_Set_Internal (Left) or Character_Set_Internal (Right));
  87    end "or";
  88 
  89    -----------
  90    -- "xor" --
  91    -----------
  92 
  93    function "xor" (Left, Right : Character_Set) return Character_Set is
  94    begin
  95       return Character_Set
  96         (Character_Set_Internal (Left) xor Character_Set_Internal (Right));
  97    end "xor";
  98 
  99    -----------
 100    -- Is_In --
 101    -----------
 102 
 103    function Is_In
 104      (Element : Character;
 105       Set     : Character_Set) return Boolean
 106    is
 107    begin
 108       return Set (Element);
 109    end Is_In;
 110 
 111    ---------------
 112    -- Is_Subset --
 113    ---------------
 114 
 115    function Is_Subset
 116      (Elements : Character_Set;
 117       Set      : Character_Set) return Boolean
 118    is
 119    begin
 120       return (Elements and Set) = Elements;
 121    end Is_Subset;
 122 
 123    ---------------
 124    -- To_Domain --
 125    ---------------
 126 
 127    function To_Domain (Map : Character_Mapping) return Character_Sequence
 128    is
 129       Result : String (1 .. Map'Length);
 130       J      : Natural;
 131 
 132    begin
 133       J := 0;
 134       for C in Map'Range loop
 135          if Map (C) /= C then
 136             J := J + 1;
 137             Result (J) := C;
 138          end if;
 139       end loop;
 140 
 141       return Result (1 .. J);
 142    end To_Domain;
 143 
 144    ----------------
 145    -- To_Mapping --
 146    ----------------
 147 
 148    function To_Mapping
 149      (From, To : Character_Sequence) return Character_Mapping
 150    is
 151       Result   : Character_Mapping;
 152       Inserted : Character_Set := Null_Set;
 153       From_Len : constant Natural := From'Length;
 154       To_Len   : constant Natural := To'Length;
 155 
 156    begin
 157       if From_Len /= To_Len then
 158          raise Strings.Translation_Error;
 159       end if;
 160 
 161       for Char in Character loop
 162          Result (Char) := Char;
 163       end loop;
 164 
 165       for J in From'Range loop
 166          if Inserted (From (J)) then
 167             raise Strings.Translation_Error;
 168          end if;
 169 
 170          Result   (From (J)) := To (J - From'First + To'First);
 171          Inserted (From (J)) := True;
 172       end loop;
 173 
 174       return Result;
 175    end To_Mapping;
 176 
 177    --------------
 178    -- To_Range --
 179    --------------
 180 
 181    function To_Range (Map : Character_Mapping) return Character_Sequence
 182    is
 183       Result : String (1 .. Map'Length);
 184       J      : Natural;
 185    begin
 186       J := 0;
 187       for C in Map'Range loop
 188          if Map (C) /= C then
 189             J := J + 1;
 190             Result (J) := Map (C);
 191          end if;
 192       end loop;
 193 
 194       return Result (1 .. J);
 195    end To_Range;
 196 
 197    ---------------
 198    -- To_Ranges --
 199    ---------------
 200 
 201    function To_Ranges (Set : Character_Set) return Character_Ranges is
 202       Max_Ranges : Character_Ranges (1 .. Set'Length / 2 + 1);
 203       Range_Num  : Natural;
 204       C          : Character;
 205 
 206    begin
 207       C := Character'First;
 208       Range_Num := 0;
 209 
 210       loop
 211          --  Skip gap between subsets
 212 
 213          while not Set (C) loop
 214             exit when C = Character'Last;
 215             C := Character'Succ (C);
 216          end loop;
 217 
 218          exit when not Set (C);
 219 
 220          Range_Num := Range_Num + 1;
 221          Max_Ranges (Range_Num).Low := C;
 222 
 223          --  Span a subset
 224 
 225          loop
 226             exit when not Set (C) or else C = Character'Last;
 227             C := Character'Succ (C);
 228          end loop;
 229 
 230          if Set (C) then
 231             Max_Ranges (Range_Num). High := C;
 232             exit;
 233          else
 234             Max_Ranges (Range_Num). High := Character'Pred (C);
 235          end if;
 236       end loop;
 237 
 238       return Max_Ranges (1 .. Range_Num);
 239    end To_Ranges;
 240 
 241    -----------------
 242    -- To_Sequence --
 243    -----------------
 244 
 245    function To_Sequence (Set : Character_Set) return Character_Sequence is
 246       Result : String (1 .. Character'Pos (Character'Last) + 1);
 247       Count  : Natural := 0;
 248    begin
 249       for Char in Set'Range loop
 250          if Set (Char) then
 251             Count := Count + 1;
 252             Result (Count) := Char;
 253          end if;
 254       end loop;
 255 
 256       return Result (1 .. Count);
 257    end To_Sequence;
 258 
 259    ------------
 260    -- To_Set --
 261    ------------
 262 
 263    function To_Set (Ranges : Character_Ranges) return Character_Set is
 264       Result : Character_Set;
 265    begin
 266       for C in Result'Range loop
 267          Result (C) := False;
 268       end loop;
 269 
 270       for R in Ranges'Range loop
 271          for C in Ranges (R).Low .. Ranges (R).High loop
 272             Result (C) := True;
 273          end loop;
 274       end loop;
 275 
 276       return Result;
 277    end To_Set;
 278 
 279    function To_Set (Span : Character_Range) return Character_Set is
 280       Result : Character_Set;
 281    begin
 282       for C in Result'Range loop
 283          Result (C) := False;
 284       end loop;
 285 
 286       for C in Span.Low .. Span.High loop
 287          Result (C) := True;
 288       end loop;
 289 
 290       return Result;
 291    end To_Set;
 292 
 293    function To_Set (Sequence : Character_Sequence) return Character_Set is
 294       Result : Character_Set := Null_Set;
 295    begin
 296       for J in Sequence'Range loop
 297          Result (Sequence (J)) := True;
 298       end loop;
 299 
 300       return Result;
 301    end To_Set;
 302 
 303    function To_Set (Singleton : Character) return Character_Set is
 304       Result : Character_Set := Null_Set;
 305    begin
 306       Result (Singleton) := True;
 307       return Result;
 308    end To_Set;
 309 
 310    -----------
 311    -- Value --
 312    -----------
 313 
 314    function Value
 315      (Map     : Character_Mapping;
 316       Element : Character) return Character
 317    is
 318    begin
 319       return Map (Element);
 320    end Value;
 321 
 322 end Ada.Strings.Maps;