gcc/ada/libgnat/g-arrspl.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     G N A T . A R R A Y _ S P L I T                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2002-2017, 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 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  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 with Ada.Unchecked_Deallocation;
  33
  34 package body GNAT.Array_Split is
  35
  36    procedure Free is
  37       new Ada.Unchecked_Deallocation (Slices_Indexes, Slices_Access);
  38
  39    procedure Free is
  40       new Ada.Unchecked_Deallocation (Separators_Indexes, Indexes_Access);
  41
  42    function Count
  43      (Source  : Element_Sequence;
  44       Pattern : Element_Set) return Natural;
  45    --  Returns the number of occurrences of Pattern elements in Source, 0 is
  46    --  returned if no occurrence is found in Source.
  47
  48    ------------
  49    -- Adjust --
  50    ------------
  51
  52    procedure Adjust (S : in out Slice_Set) is
  53    begin
  54       S.D.Ref_Counter := S.D.Ref_Counter + 1;
  55    end Adjust;
  56
  57    ------------
  58    -- Create --
  59    ------------
  60
  61    procedure Create
  62      (S          : out Slice_Set;
  63       From       : Element_Sequence;
  64       Separators : Element_Sequence;
  65       Mode       : Separator_Mode := Single)
  66    is
  67    begin
  68       Create (S, From, To_Set (Separators), Mode);
  69    end Create;
  70
  71    ------------
  72    -- Create --
  73    ------------
  74
  75    procedure Create
  76      (S          : out Slice_Set;
  77       From       : Element_Sequence;
  78       Separators : Element_Set;
  79       Mode       : Separator_Mode := Single)
  80    is
  81       Result : Slice_Set;
  82    begin
  83       Result.D.Source := new Element_Sequence'(From);
  84       Set (Result, Separators, Mode);
  85       S := Result;
  86    end Create;
  87
  88    -----------
  89    -- Count --
  90    -----------
  91
  92    function Count
  93      (Source  : Element_Sequence;
  94       Pattern : Element_Set) return Natural
  95    is
  96       C : Natural := 0;
  97    begin
  98       for K in Source'Range loop
  99          if Is_In (Source (K), Pattern) then
 100             C := C + 1;
 101          end if;
 102       end loop;
 103
 104       return C;
 105    end Count;
 106
 107    --------------
 108    -- Finalize --
 109    --------------
 110
 111    procedure Finalize (S : in out Slice_Set) is
 112
 113       procedure Free is
 114          new Ada.Unchecked_Deallocation (Element_Sequence, Element_Access);
 115
 116       procedure Free is
 117          new Ada.Unchecked_Deallocation (Data, Data_Access);
 118
 119       D : Data_Access := S.D;
 120
 121    begin
 122       --  Ensure call is idempotent
 123
 124       S.D := null;
 125
 126       if D /= null then
 127          D.Ref_Counter := D.Ref_Counter - 1;
 128
 129          if D.Ref_Counter = 0 then
 130             Free (D.Source);
 131             Free (D.Indexes);
 132             Free (D.Slices);
 133             Free (D);
 134          end if;
 135       end if;
 136    end Finalize;
 137
 138    ----------------
 139    -- Initialize --
 140    ----------------
 141
 142    procedure Initialize (S : in out Slice_Set) is
 143    begin
 144       S.D := new Data'(1, null, 0, null, null);
 145    end Initialize;
 146
 147    ----------------
 148    -- Separators --
 149    ----------------
 150
 151    function Separators
 152      (S     : Slice_Set;
 153       Index : Slice_Number) return Slice_Separators
 154    is
 155    begin
 156       if Index > S.D.N_Slice then
 157          raise Index_Error;
 158
 159       elsif Index = 0
 160         or else (Index = 1 and then S.D.N_Slice = 1)
 161       then
 162          --  Whole string, or no separator used
 163
 164          return (Before => Array_End,
 165                  After  => Array_End);
 166
 167       elsif Index = 1 then
 168          return (Before => Array_End,
 169                  After  => S.D.Source (S.D.Slices (Index).Stop + 1));
 170
 171       elsif Index = S.D.N_Slice then
 172          return (Before => S.D.Source (S.D.Slices (Index).Start - 1),
 173                  After  => Array_End);
 174
 175       else
 176          return (Before => S.D.Source (S.D.Slices (Index).Start - 1),
 177                  After  => S.D.Source (S.D.Slices (Index).Stop + 1));
 178       end if;
 179    end Separators;
 180
 181    ----------------
 182    -- Separators --
 183    ----------------
 184
 185    function Separators (S : Slice_Set) return Separators_Indexes is
 186    begin
 187       return S.D.Indexes.all;
 188    end Separators;
 189
 190    ---------
 191    -- Set --
 192    ---------
 193
 194    procedure Set
 195      (S          : in out Slice_Set;
 196       Separators : Element_Sequence;
 197       Mode       : Separator_Mode := Single)
 198    is
 199    begin
 200       Set (S, To_Set (Separators), Mode);
 201    end Set;
 202
 203    ---------
 204    -- Set --
 205    ---------
 206
 207    procedure Set
 208      (S          : in out Slice_Set;
 209       Separators : Element_Set;
 210       Mode       : Separator_Mode := Single)
 211    is
 212
 213       procedure Copy_On_Write (S : in out Slice_Set);
 214       --  Make a copy of S if shared with another variable
 215
 216       -------------------
 217       -- Copy_On_Write --
 218       -------------------
 219
 220       procedure Copy_On_Write (S : in out Slice_Set) is
 221       begin
 222          if S.D.Ref_Counter > 1 then
 223             --  First let's remove our count from the current data
 224
 225             S.D.Ref_Counter := S.D.Ref_Counter - 1;
 226
 227             --  Then duplicate the data
 228
 229             S.D := new Data'(S.D.all);
 230             S.D.Ref_Counter := 1;
 231
 232             if S.D.Source /= null then
 233                S.D.Source := new Element_Sequence'(S.D.Source.all);
 234                S.D.Indexes := null;
 235                S.D.Slices := null;
 236             end if;
 237
 238          else
 239             --  If there is a single reference to this variable, free it now
 240             --  as it will be redefined below.
 241
 242             Free (S.D.Indexes);
 243             Free (S.D.Slices);
 244          end if;
 245       end Copy_On_Write;
 246
 247       Count_Sep : constant Natural := Count (S.D.Source.all, Separators);
 248       J         : Positive;
 249
 250    begin
 251       Copy_On_Write (S);
 252
 253       --  Compute all separator's indexes
 254
 255       S.D.Indexes := new Separators_Indexes (1 .. Count_Sep);
 256       J := S.D.Indexes'First;
 257
 258       for K in S.D.Source'Range loop
 259          if Is_In (S.D.Source (K), Separators) then
 260             S.D.Indexes (J) := K;
 261             J := J + 1;
 262          end if;
 263       end loop;
 264
 265       --  Compute slice info for fast slice access
 266
 267       declare
 268          S_Info      : Slices_Indexes (1 .. Slice_Number (Count_Sep) + 1);
 269          K           : Natural := 1;
 270          Start, Stop : Natural;
 271
 272       begin
 273          S.D.N_Slice := 0;
 274
 275          Start := S.D.Source'First;
 276          Stop  := 0;
 277
 278          loop
 279             if K > Count_Sep then
 280
 281                --  No more separators, last slice ends at end of source string
 282
 283                Stop := S.D.Source'Last;
 284
 285             else
 286                Stop := S.D.Indexes (K) - 1;
 287             end if;
 288
 289             --  Add slice to the table
 290
 291             S.D.N_Slice := S.D.N_Slice + 1;
 292             S_Info (S.D.N_Slice) := (Start, Stop);
 293
 294             exit when K > Count_Sep;
 295
 296             case Mode is
 297                when Single =>
 298
 299                   --  In this mode just set start to character next to the
 300                   --  current separator, advance the separator index.
 301
 302                   Start := S.D.Indexes (K) + 1;
 303                   K := K + 1;
 304
 305                when Multiple =>
 306
 307                   --  In this mode skip separators following each other
 308
 309                   loop
 310                      Start := S.D.Indexes (K) + 1;
 311                      K := K + 1;
 312                      exit when K > Count_Sep
 313                        or else S.D.Indexes (K) > S.D.Indexes (K - 1) + 1;
 314                   end loop;
 315             end case;
 316          end loop;
 317
 318          S.D.Slices := new Slices_Indexes'(S_Info (1 .. S.D.N_Slice));
 319       end;
 320    end Set;
 321
 322    -----------
 323    -- Slice --
 324    -----------
 325
 326    function Slice
 327      (S     : Slice_Set;
 328       Index : Slice_Number) return Element_Sequence
 329    is
 330    begin
 331       if Index = 0 then
 332          return S.D.Source.all;
 333
 334       elsif Index > S.D.N_Slice then
 335          raise Index_Error;
 336
 337       else
 338          return
 339            S.D.Source (S.D.Slices (Index).Start .. S.D.Slices (Index).Stop);
 340       end if;
 341    end Slice;
 342
 343    -----------------
 344    -- Slice_Count --
 345    -----------------
 346
 347    function Slice_Count (S : Slice_Set) return Slice_Number is
 348    begin
 349       return S.D.N_Slice;
 350    end Slice_Count;
 351
 352 end GNAT.Array_Split;