File : a-strunb.adb


------------------------------------------------------------------------------

--                                                                          --

--                          GNAT RUNTIME COMPONENTS                         --

--                                                                          --

--                A D A . S T R I N G S . U N B O U N D E D                 --

--                                                                          --

--                                 B o d y                                  --

--                                                                          --

--          Copyright (C) 1992-2002 Free Software Foundation, Inc.          --

--                                                                          --

-- GNAT is free software;  you can  redistribute it  and/or modify it under --

-- terms of the  GNU General Public License as published  by the Free Soft- --

-- ware  Foundation;  either version 2,  or (at your option) any later ver- --

-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --

-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --

-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --

-- for  more details.  You should have  received  a copy of the GNU General --

-- Public License  distributed with GNAT;  see file COPYING.  If not, write --

-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --

-- MA 02111-1307, USA.                                                      --

--                                                                          --

-- As a special exception,  if other files  instantiate  generics from this --

-- unit, or you link  this unit with other files  to produce an executable, --

-- this  unit  does not  by itself cause  the resulting  executable  to  be --

-- covered  by the  GNU  General  Public  License.  This exception does not --

-- however invalidate  any other reasons why  the executable file  might be --

-- covered by the  GNU Public License.                                      --

--                                                                          --

-- GNAT was originally developed  by the GNAT team at  New York University. --

-- Extensive contributions were provided by Ada Core Technologies Inc.      --

--                                                                          --

------------------------------------------------------------------------------


with Ada.Strings.Fixed;
with Ada.Strings.Search;
with Ada.Unchecked_Deallocation;

package body Ada.Strings.Unbounded is

   use Ada.Finalization;

   procedure Realloc_For_Chunk
     (Source     : in out Unbounded_String;
      Chunk_Size : Natural);
   pragma Inline (Realloc_For_Chunk);
   --  Adjust the size allocated for the string. Add at least Chunk_Size so it

   --  is safe to add a string of this size at the end of the current

   --  content. The real size allocated for the string is Chunk_Size + x %

   --  of the current string size. This buffered handling makes the Append

   --  unbounded string routines very fast.


   ---------

   -- "&" --

   ---------


   function "&" (Left, Right : Unbounded_String) return Unbounded_String is
      L_Length : constant Natural := Left.Last;
      R_Length : constant Natural := Right.Last;
      Result   : Unbounded_String;

   begin
      Result.Last := L_Length + R_Length;

      Result.Reference := new String (1 .. Result.Last);

      Result.Reference (1 .. L_Length) :=
        Left.Reference (1 .. Left.Last);
      Result.Reference (L_Length + 1 .. Result.Last) :=
        Right.Reference (1 .. Right.Last);

      return Result;
   end "&";

   function "&"
     (Left  : Unbounded_String;
      Right : String)
      return  Unbounded_String
   is
      L_Length : constant Natural := Left.Last;
      Result   : Unbounded_String;

   begin
      Result.Last := L_Length + Right'Length;

      Result.Reference := new String (1 .. Result.Last);

      Result.Reference (1 .. L_Length) := Left.Reference (1 .. Left.Last);
      Result.Reference (L_Length + 1 .. Result.Last) := Right;

      return Result;
   end "&";

   function "&"
     (Left  : String;
      Right : Unbounded_String)
      return  Unbounded_String
   is
      R_Length : constant Natural := Right.Last;
      Result   : Unbounded_String;

   begin
      Result.Last := Left'Length + R_Length;

      Result.Reference := new String (1 .. Result.Last);

      Result.Reference (1 .. Left'Length) := Left;
      Result.Reference (Left'Length + 1 .. Result.Last) :=
        Right.Reference (1 .. Right.Last);

      return Result;
   end "&";

   function "&"
     (Left  : Unbounded_String;
      Right : Character)
      return  Unbounded_String
   is
      Result : Unbounded_String;

   begin
      Result.Last := Left.Last + 1;

      Result.Reference := new String (1 .. Result.Last);

      Result.Reference (1 .. Result.Last - 1) :=
        Left.Reference (1 .. Left.Last);
      Result.Reference (Result.Last) := Right;

      return Result;
   end "&";

   function "&"
     (Left  : Character;
      Right : Unbounded_String)
      return  Unbounded_String
   is
      Result : Unbounded_String;

   begin
      Result.Last := Right.Last + 1;

      Result.Reference := new String (1 .. Result.Last);
      Result.Reference (1) := Left;
      Result.Reference (2 .. Result.Last) :=
        Right.Reference (1 .. Right.Last);
      return Result;
   end "&";

   ---------

   -- "*" --

   ---------


   function "*"
     (Left  : Natural;
      Right : Character)
      return  Unbounded_String
   is
      Result : Unbounded_String;

   begin
      Result.Last   := Left;

      Result.Reference := new String (1 .. Left);
      for J in Result.Reference'Range loop
         Result.Reference (J) := Right;
      end loop;

      return Result;
   end "*";

   function "*"
     (Left  : Natural;
      Right : String)
     return   Unbounded_String
   is
      Len    : constant Natural := Right'Length;
      K      : Positive;
      Result : Unbounded_String;

   begin
      Result.Last := Left * Len;

      Result.Reference := new String (1 .. Result.Last);

      K := 1;
      for J in 1 .. Left loop
         Result.Reference (K .. K + Len - 1) := Right;
         K := K + Len;
      end loop;

      return Result;
   end "*";

   function "*"
     (Left  : Natural;
      Right : Unbounded_String)
      return  Unbounded_String
   is
      Len    : constant Natural := Right.Last;
      K      : Positive;
      Result : Unbounded_String;

   begin
      Result.Last := Left * Len;

      Result.Reference := new String (1 .. Result.Last);

      K := 1;
      for I in 1 .. Left loop
         Result.Reference (K .. K + Len - 1) :=
           Right.Reference (1 .. Right.Last);
         K := K + Len;
      end loop;

      return Result;
   end "*";

   ---------

   -- "<" --

   ---------


   function "<" (Left, Right : Unbounded_String) return Boolean is
   begin
      return
        Left.Reference (1 .. Left.Last) < Right.Reference (1 .. Right.Last);
   end "<";

   function "<"
     (Left  : Unbounded_String;
      Right : String)
      return  Boolean
   is
   begin
      return Left.Reference (1 .. Left.Last) < Right;
   end "<";

   function "<"
     (Left  : String;
      Right : Unbounded_String)
      return  Boolean
   is
   begin
      return Left < Right.Reference (1 .. Right.Last);
   end "<";

   ----------

   -- "<=" --

   ----------


   function "<=" (Left, Right : Unbounded_String) return Boolean is
   begin
      return
        Left.Reference (1 .. Left.Last) <= Right.Reference (1 .. Right.Last);
   end "<=";

   function "<="
     (Left  : Unbounded_String;
      Right : String)
      return  Boolean
   is
   begin
      return Left.Reference (1 .. Left.Last) <= Right;
   end "<=";

   function "<="
     (Left  : String;
      Right : Unbounded_String)
      return  Boolean
   is
   begin
      return Left <= Right.Reference (1 .. Right.Last);
   end "<=";

   ---------

   -- "=" --

   ---------


   function "=" (Left, Right : Unbounded_String) return Boolean is
   begin
      return
        Left.Reference (1 .. Left.Last) = Right.Reference (1 .. Right.Last);
   end "=";

   function "="
     (Left  : Unbounded_String;
      Right : String)
      return  Boolean
   is
   begin
      return Left.Reference (1 .. Left.Last) = Right;
   end "=";

   function "="
     (Left  : String;
      Right : Unbounded_String)
      return  Boolean
   is
   begin
      return Left = Right.Reference (1 .. Right.Last);
   end "=";

   ---------

   -- ">" --

   ---------


   function ">"  (Left, Right : Unbounded_String) return Boolean is
   begin
      return
        Left.Reference (1 .. Left.Last) > Right.Reference (1 .. Right.Last);
   end ">";

   function ">"
     (Left  : Unbounded_String;
      Right : String)
      return  Boolean
   is
   begin
      return Left.Reference (1 .. Left.Last) > Right;
   end ">";

   function ">"
     (Left  : String;
      Right : Unbounded_String)
      return  Boolean
   is
   begin
      return Left > Right.Reference (1 .. Right.Last);
   end ">";

   ----------

   -- ">=" --

   ----------


   function ">=" (Left, Right : Unbounded_String) return Boolean is
   begin
      return
        Left.Reference (1 .. Left.Last) >= Right.Reference (1 .. Right.Last);
   end ">=";

   function ">="
     (Left  : Unbounded_String;
      Right : String)
      return  Boolean
   is
   begin
      return Left.Reference (1 .. Left.Last) >= Right;
   end ">=";

   function ">="
     (Left  : String;
      Right : Unbounded_String)
      return  Boolean
   is
   begin
      return Left >= Right.Reference (1 .. Right.Last);
   end ">=";

   ------------

   -- Adjust --

   ------------


   procedure Adjust (Object : in out Unbounded_String) is
   begin
      --  Copy string, except we do not copy the statically allocated null

      --  string, since it can never be deallocated.

      --  Note that we do not copy extra string room here to avoid dragging

      --  unused allocated memory.


      if Object.Reference /= Null_String'Access then
         Object.Reference := new String'(Object.Reference (1 .. Object.Last));
      end if;
   end Adjust;

   ------------

   -- Append --

   ------------


   procedure Append
     (Source   : in out Unbounded_String;
      New_Item : Unbounded_String)
   is
   begin
      Realloc_For_Chunk (Source, New_Item.Last);
      Source.Reference (Source.Last + 1 .. Source.Last + New_Item.Last) :=
        New_Item.Reference (1 .. New_Item.Last);
      Source.Last := Source.Last + New_Item.Last;
   end Append;

   procedure Append
     (Source   : in out Unbounded_String;
      New_Item : String)
   is
   begin
      Realloc_For_Chunk (Source, New_Item'Length);
      Source.Reference (Source.Last + 1 .. Source.Last + New_Item'Length) :=
        New_Item;
      Source.Last := Source.Last + New_Item'Length;
   end Append;

   procedure Append
     (Source   : in out Unbounded_String;
      New_Item : Character)
   is
   begin
      Realloc_For_Chunk (Source, 1);
      Source.Reference (Source.Last + 1) := New_Item;
      Source.Last := Source.Last + 1;
   end Append;

   -----------

   -- Count --

   -----------


   function Count
     (Source   : Unbounded_String;
      Pattern  : String;
      Mapping  : Maps.Character_Mapping := Maps.Identity)
      return     Natural
   is
   begin
      return
        Search.Count (Source.Reference (1 .. Source.Last), Pattern, Mapping);
   end Count;

   function Count
     (Source   : Unbounded_String;
      Pattern  : String;
      Mapping  : Maps.Character_Mapping_Function)
      return     Natural
   is
   begin
      return
        Search.Count (Source.Reference (1 .. Source.Last), Pattern, Mapping);
   end Count;

   function Count
     (Source   : Unbounded_String;
      Set      : Maps.Character_Set)
      return     Natural
   is
   begin
      return Search.Count (Source.Reference (1 .. Source.Last), Set);
   end Count;

   ------------

   -- Delete --

   ------------


   function Delete
     (Source  : Unbounded_String;
      From    : Positive;
      Through : Natural)
      return    Unbounded_String
   is
   begin
      return
        To_Unbounded_String
          (Fixed.Delete (Source.Reference (1 .. Source.Last), From, Through));
   end Delete;

   procedure Delete
     (Source  : in out Unbounded_String;
      From    : Positive;
      Through : Natural)
   is
   begin
      if From > Through then
         null;

      elsif From < Source.Reference'First or else Through > Source.Last then
         raise Index_Error;

      else
         declare
            Len : constant Natural := Through - From + 1;

         begin
            Source.Reference (From .. Source.Last - Len) :=
              Source.Reference (Through + 1 .. Source.Last);
            Source.Last := Source.Last - Len;
         end;
      end if;
   end Delete;

   -------------

   -- Element --

   -------------


   function Element
     (Source : Unbounded_String;
      Index  : Positive)
      return   Character
   is
   begin
      if Index <= Source.Last then
         return Source.Reference (Index);
      else
         raise Strings.Index_Error;
      end if;
   end Element;

   --------------

   -- Finalize --

   --------------


   procedure Finalize (Object : in out Unbounded_String) is
      procedure Deallocate is
         new Ada.Unchecked_Deallocation (String, String_Access);

   begin
      --  Note: Don't try to free statically allocated null string


      if Object.Reference /= Null_String'Access then
         Deallocate (Object.Reference);
         Object.Reference := Null_Unbounded_String.Reference;
         Object.Last := 0;
      end if;
   end Finalize;

   ----------------

   -- Find_Token --

   ----------------


   procedure Find_Token
     (Source : Unbounded_String;
      Set    : Maps.Character_Set;
      Test   : Strings.Membership;
      First  : out Positive;
      Last   : out Natural)
   is
   begin
      Search.Find_Token
        (Source.Reference (1 .. Source.Last), Set, Test, First, Last);
   end Find_Token;

   ----------

   -- Free --

   ----------


   procedure Free (X : in out String_Access) is
      procedure Deallocate is
         new Ada.Unchecked_Deallocation (String, String_Access);

   begin
      --  Note: Do not try to free statically allocated null string


      if X /= Null_Unbounded_String.Reference then
         Deallocate (X);
      end if;
   end Free;

   ----------

   -- Head --

   ----------


   function Head
     (Source : Unbounded_String;
      Count  : Natural;
      Pad    : Character := Space)
      return   Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Head (Source.Reference (1 .. Source.Last), Count, Pad));
   end Head;

   procedure Head
     (Source : in out Unbounded_String;
      Count  : Natural;
      Pad    : Character := Space)
   is
      Old : String_Access := Source.Reference;

   begin
      Source.Reference :=
        new String'(Fixed.Head (Source.Reference (1 .. Source.Last),
                    Count, Pad));
      Source.Last := Source.Reference'Length;
      Free (Old);
   end Head;

   -----------

   -- Index --

   -----------


   function Index
     (Source   : Unbounded_String;
      Pattern  : String;
      Going    : Strings.Direction := Strings.Forward;
      Mapping  : Maps.Character_Mapping := Maps.Identity)
      return     Natural
   is
   begin
      return Search.Index
        (Source.Reference (1 .. Source.Last), Pattern, Going, Mapping);
   end Index;

   function Index
     (Source   : Unbounded_String;
      Pattern  : String;
      Going    : Direction := Forward;
      Mapping  : Maps.Character_Mapping_Function)
      return     Natural
   is
   begin
      return Search.Index
        (Source.Reference (1 .. Source.Last), Pattern, Going, Mapping);
   end Index;

   function Index
     (Source : Unbounded_String;
      Set    : Maps.Character_Set;
      Test   : Strings.Membership := Strings.Inside;
      Going  : Strings.Direction  := Strings.Forward)
      return   Natural
   is
   begin
      return Search.Index
        (Source.Reference (1 .. Source.Last), Set, Test, Going);
   end Index;

   function Index_Non_Blank
     (Source : Unbounded_String;
      Going  : Strings.Direction := Strings.Forward)
      return   Natural
   is
   begin
      return
        Search.Index_Non_Blank (Source.Reference (1 .. Source.Last), Going);
   end Index_Non_Blank;

   ----------------

   -- Initialize --

   ----------------


   procedure Initialize (Object : in out Unbounded_String) is
   begin
      Object.Reference := Null_Unbounded_String.Reference;
      Object.Last      := 0;
   end Initialize;

   ------------

   -- Insert --

   ------------


   function Insert
     (Source   : Unbounded_String;
      Before   : Positive;
      New_Item : String)
      return     Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Insert (Source.Reference (1 .. Source.Last), Before, New_Item));
   end Insert;

   procedure Insert
     (Source   : in out Unbounded_String;
      Before   : Positive;
      New_Item : String)
   is
   begin
      if Before not in Source.Reference'First .. Source.Last + 1 then
         raise Index_Error;
      end if;

      Realloc_For_Chunk (Source, New_Item'Size);

      Source.Reference
        (Before +  New_Item'Length .. Source.Last + New_Item'Length) :=
           Source.Reference (Before .. Source.Last);

      Source.Reference (Before .. Before + New_Item'Length - 1) := New_Item;
      Source.Last := Source.Last + New_Item'Length;
   end Insert;

   ------------

   -- Length --

   ------------


   function Length (Source : Unbounded_String) return Natural is
   begin
      return Source.Last;
   end Length;

   ---------------

   -- Overwrite --

   ---------------


   function Overwrite
     (Source    : Unbounded_String;
      Position  : Positive;
      New_Item  : String)
      return      Unbounded_String is

   begin
      return To_Unbounded_String
        (Fixed.Overwrite
          (Source.Reference (1 .. Source.Last), Position, New_Item));
   end Overwrite;

   procedure Overwrite
     (Source    : in out Unbounded_String;
      Position  : Positive;
      New_Item  : String)
   is
      NL : constant Natural := New_Item'Length;

   begin
      if Position <= Source.Last - NL + 1 then
         Source.Reference (Position .. Position + NL - 1) := New_Item;

      else
         declare
            Old : String_Access := Source.Reference;

         begin
            Source.Reference := new String'
              (Fixed.Overwrite
                (Source.Reference (1 .. Source.Last), Position, New_Item));
            Source.Last := Source.Reference'Length;
            Free (Old);
         end;
      end if;
   end Overwrite;

   -----------------------

   -- Realloc_For_Chunk --

   -----------------------


   procedure Realloc_For_Chunk
     (Source     : in out Unbounded_String;
      Chunk_Size : Natural)
   is
      Growth_Factor : constant := 50;
      S_Length      : constant Natural := Source.Reference'Length;

   begin
      if Chunk_Size > S_Length - Source.Last then
         declare
            Alloc_Chunk_Size : constant Positive :=
                                 Chunk_Size + (S_Length / Growth_Factor);
            Tmp : String_Access;

         begin
            Tmp := new String (1 .. S_Length + Alloc_Chunk_Size);
            Tmp (1 .. Source.Last) := Source.Reference (1 .. Source.Last);
            Free (Source.Reference);
            Source.Reference := Tmp;
         end;
      end if;
   end Realloc_For_Chunk;

   ---------------------

   -- Replace_Element --

   ---------------------


   procedure Replace_Element
     (Source : in out Unbounded_String;
      Index  : Positive;
      By     : Character)
   is
   begin
      if Index <= Source.Last then
         Source.Reference (Index) := By;
      else
         raise Strings.Index_Error;
      end if;
   end Replace_Element;

   -------------------

   -- Replace_Slice --

   -------------------


   function Replace_Slice
     (Source   : Unbounded_String;
      Low      : Positive;
      High     : Natural;
      By       : String)
      return     Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Replace_Slice
           (Source.Reference (1 .. Source.Last), Low, High, By));
   end Replace_Slice;

   procedure Replace_Slice
     (Source   : in out Unbounded_String;
      Low      : Positive;
      High     : Natural;
      By       : String)
   is
      Old : String_Access := Source.Reference;

   begin
      Source.Reference := new String'
        (Fixed.Replace_Slice
           (Source.Reference (1 .. Source.Last), Low, High, By));
      Source.Last := Source.Reference'Length;
      Free (Old);
   end Replace_Slice;

   -----------

   -- Slice --

   -----------


   function Slice
     (Source : Unbounded_String;
      Low    : Positive;
      High   : Natural)
      return   String
   is
   begin
      --  Note: test of High > Length is in accordance with AI95-00128


      if Low > Source.Last + 1 or else High > Source.Last then
         raise Index_Error;
      else
         return Source.Reference (Low .. High);
      end if;
   end Slice;

   ----------

   -- Tail --

   ----------


   function Tail
     (Source : Unbounded_String;
      Count  : Natural;
      Pad    : Character := Space)
      return   Unbounded_String is

   begin
      return To_Unbounded_String
        (Fixed.Tail (Source.Reference (1 .. Source.Last), Count, Pad));
   end Tail;

   procedure Tail
     (Source : in out Unbounded_String;
      Count  : Natural;
      Pad    : Character := Space)
   is
      Old : String_Access := Source.Reference;

   begin
      Source.Reference := new String'
        (Fixed.Tail (Source.Reference (1 .. Source.Last), Count, Pad));
      Source.Last := Source.Reference'Length;
      Free (Old);
   end Tail;

   ---------------

   -- To_String --

   ---------------


   function To_String (Source : Unbounded_String) return String is
   begin
      return Source.Reference (1 .. Source.Last);
   end To_String;

   -------------------------

   -- To_Unbounded_String --

   -------------------------


   function To_Unbounded_String (Source : String) return Unbounded_String is
      Result : Unbounded_String;

   begin
      Result.Last          := Source'Length;
      Result.Reference     := new String (1 .. Source'Length);
      Result.Reference.all := Source;
      return Result;
   end To_Unbounded_String;

   function To_Unbounded_String
     (Length : Natural)
      return   Unbounded_String
   is
      Result : Unbounded_String;

   begin
      Result.Last      := Length;
      Result.Reference := new String (1 .. Length);
      return Result;
   end To_Unbounded_String;

   ---------------

   -- Translate --

   ---------------


   function Translate
     (Source  : Unbounded_String;
      Mapping : Maps.Character_Mapping)
      return    Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping));
   end Translate;

   procedure Translate
     (Source  : in out Unbounded_String;
      Mapping : Maps.Character_Mapping)
   is
   begin
      Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping);
   end Translate;

   function Translate
     (Source  : Unbounded_String;
      Mapping : Maps.Character_Mapping_Function)
      return    Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping));
   end Translate;

   procedure Translate
     (Source  : in out Unbounded_String;
      Mapping : Maps.Character_Mapping_Function)
   is
   begin
      Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping);
   end Translate;

   ----------

   -- Trim --

   ----------


   function Trim
     (Source : Unbounded_String;
      Side   : Trim_End)
      return   Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Trim (Source.Reference (1 .. Source.Last), Side));
   end Trim;

   procedure Trim
     (Source : in out Unbounded_String;
      Side   : Trim_End)
   is
      Old : String_Access := Source.Reference;

   begin
      Source.Reference := new String'
        (Fixed.Trim (Source.Reference (1 .. Source.Last), Side));
      Source.Last      := Source.Reference'Length;
      Free (Old);
   end Trim;

   function Trim
     (Source : Unbounded_String;
      Left   : Maps.Character_Set;
      Right  : Maps.Character_Set)
      return   Unbounded_String
   is
   begin
      return To_Unbounded_String
        (Fixed.Trim (Source.Reference (1 .. Source.Last), Left, Right));
   end Trim;

   procedure Trim
     (Source : in out Unbounded_String;
      Left   : Maps.Character_Set;
      Right  : Maps.Character_Set)
   is
      Old : String_Access := Source.Reference;

   begin
      Source.Reference := new String'
        (Fixed.Trim (Source.Reference (1 .. Source.Last), Left, Right));
      Source.Last      := Source.Reference'Length;
      Free (Old);
   end Trim;

end Ada.Strings.Unbounded;