| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUNTIME COMPONENTS -- |
| -- -- |
| -- A D A . S T R I N G S . S E A R C H -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992,1993,1994,1995,1996 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Note: This code is derived from the ADAR.CSH public domain Ada 83 |
| -- versions of the Appendix C string handling packages (code extracted |
| -- from Ada.Strings.Fixed). A significant change is that we optimize the |
| -- case of identity mappings for Count and Index, and also Index_Non_Blank |
| -- is specialized (rather than using the general Index routine). |
| |
| |
| with Ada.Strings.Maps; use Ada.Strings.Maps; |
| |
| package body Ada.Strings.Search is |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Belongs |
| (Element : Character; |
| Set : Maps.Character_Set; |
| Test : Membership) |
| return Boolean; |
| pragma Inline (Belongs); |
| -- Determines if the given element is in (Test = Inside) or not in |
| -- (Test = Outside) the given character set. |
| |
| ------------- |
| -- Belongs -- |
| ------------- |
| |
| function Belongs |
| (Element : Character; |
| Set : Maps.Character_Set; |
| Test : Membership) |
| return Boolean |
| is |
| begin |
| if Test = Inside then |
| return Is_In (Element, Set); |
| else |
| return not Is_In (Element, Set); |
| end if; |
| end Belongs; |
| |
| ----------- |
| -- Count -- |
| ----------- |
| |
| function Count |
| (Source : in String; |
| Pattern : in String; |
| Mapping : in Maps.Character_Mapping := Maps.Identity) |
| return Natural |
| is |
| N : Natural; |
| J : Natural; |
| |
| Mapped_Source : String (Source'Range); |
| |
| begin |
| for J in Source'Range loop |
| Mapped_Source (J) := Value (Mapping, Source (J)); |
| end loop; |
| |
| if Pattern = "" then |
| raise Pattern_Error; |
| end if; |
| |
| N := 0; |
| J := Source'First; |
| |
| while J <= Source'Last - (Pattern'Length - 1) loop |
| if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then |
| N := N + 1; |
| J := J + Pattern'Length; |
| else |
| J := J + 1; |
| end if; |
| end loop; |
| |
| return N; |
| end Count; |
| |
| function Count |
| (Source : in String; |
| Pattern : in String; |
| Mapping : in Maps.Character_Mapping_Function) |
| return Natural |
| is |
| Mapped_Source : String (Source'Range); |
| N : Natural; |
| J : Natural; |
| |
| begin |
| if Pattern = "" then |
| raise Pattern_Error; |
| end if; |
| |
| -- We make sure Access_Check is unsuppressed so that the Mapping.all |
| -- call will generate a friendly Constraint_Error if the value for |
| -- Mapping is uninitialized (and hence null). |
| |
| declare |
| pragma Unsuppress (Access_Check); |
| |
| begin |
| for J in Source'Range loop |
| Mapped_Source (J) := Mapping.all (Source (J)); |
| end loop; |
| end; |
| |
| N := 0; |
| J := Source'First; |
| |
| while J <= Source'Last - (Pattern'Length - 1) loop |
| if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then |
| N := N + 1; |
| J := J + Pattern'Length; |
| else |
| J := J + 1; |
| end if; |
| end loop; |
| |
| return N; |
| end Count; |
| |
| function Count |
| (Source : in String; |
| Set : in Maps.Character_Set) |
| return Natural |
| is |
| N : Natural := 0; |
| |
| begin |
| for J in Source'Range loop |
| if Is_In (Source (J), Set) then |
| N := N + 1; |
| end if; |
| end loop; |
| |
| return N; |
| end Count; |
| |
| ---------------- |
| -- Find_Token -- |
| ---------------- |
| |
| procedure Find_Token |
| (Source : in String; |
| Set : in Maps.Character_Set; |
| Test : in Membership; |
| First : out Positive; |
| Last : out Natural) |
| is |
| begin |
| for J in Source'Range loop |
| if Belongs (Source (J), Set, Test) then |
| First := J; |
| |
| for K in J + 1 .. Source'Last loop |
| if not Belongs (Source (K), Set, Test) then |
| Last := K - 1; |
| return; |
| end if; |
| end loop; |
| |
| -- Here if J indexes 1st char of token, and all chars |
| -- after J are in the token |
| |
| Last := Source'Last; |
| return; |
| end if; |
| end loop; |
| |
| -- Here if no token found |
| |
| First := Source'First; |
| Last := 0; |
| end Find_Token; |
| |
| ----------- |
| -- Index -- |
| ----------- |
| |
| function Index |
| (Source : in String; |
| Pattern : in String; |
| Going : in Direction := Forward; |
| Mapping : in Maps.Character_Mapping := Maps.Identity) |
| return Natural |
| is |
| Cur_Index : Natural; |
| Mapped_Source : String (Source'Range); |
| |
| |
| begin |
| if Pattern = "" then |
| raise Pattern_Error; |
| end if; |
| |
| for J in Source'Range loop |
| Mapped_Source (J) := Value (Mapping, Source (J)); |
| end loop; |
| |
| -- Forwards case |
| |
| if Going = Forward then |
| for J in 1 .. Source'Length - Pattern'Length + 1 loop |
| Cur_Index := Source'First + J - 1; |
| |
| if Pattern = Mapped_Source |
| (Cur_Index .. Cur_Index + Pattern'Length - 1) |
| then |
| return Cur_Index; |
| end if; |
| end loop; |
| |
| -- Backwards case |
| |
| else |
| for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop |
| Cur_Index := Source'First + J - 1; |
| |
| if Pattern = Mapped_Source |
| (Cur_Index .. Cur_Index + Pattern'Length - 1) |
| then |
| return Cur_Index; |
| end if; |
| end loop; |
| end if; |
| |
| -- Fall through if no match found. Note that the loops are skipped |
| -- completely in the case of the pattern being longer than the source. |
| |
| return 0; |
| end Index; |
| |
| function Index (Source : in String; |
| Pattern : in String; |
| Going : in Direction := Forward; |
| Mapping : in Maps.Character_Mapping_Function) |
| return Natural |
| is |
| Mapped_Source : String (Source'Range); |
| Cur_Index : Natural; |
| |
| begin |
| if Pattern = "" then |
| raise Pattern_Error; |
| end if; |
| |
| -- We make sure Access_Check is unsuppressed so that the Mapping.all |
| -- call will generate a friendly Constraint_Error if the value for |
| -- Mapping is uninitialized (and hence null). |
| |
| declare |
| pragma Unsuppress (Access_Check); |
| |
| begin |
| for J in Source'Range loop |
| Mapped_Source (J) := Mapping.all (Source (J)); |
| end loop; |
| end; |
| |
| -- Forwards case |
| |
| if Going = Forward then |
| for J in 1 .. Source'Length - Pattern'Length + 1 loop |
| Cur_Index := Source'First + J - 1; |
| |
| if Pattern = Mapped_Source |
| (Cur_Index .. Cur_Index + Pattern'Length - 1) |
| then |
| return Cur_Index; |
| end if; |
| end loop; |
| |
| -- Backwards case |
| |
| else |
| for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop |
| Cur_Index := Source'First + J - 1; |
| |
| if Pattern = Mapped_Source |
| (Cur_Index .. Cur_Index + Pattern'Length - 1) |
| then |
| return Cur_Index; |
| end if; |
| end loop; |
| end if; |
| |
| return 0; |
| end Index; |
| |
| function Index |
| (Source : in String; |
| Set : in Maps.Character_Set; |
| Test : in Membership := Inside; |
| Going : in Direction := Forward) |
| return Natural |
| is |
| begin |
| -- Forwards case |
| |
| if Going = Forward then |
| for J in Source'Range loop |
| if Belongs (Source (J), Set, Test) then |
| return J; |
| end if; |
| end loop; |
| |
| -- Backwards case |
| |
| else |
| for J in reverse Source'Range loop |
| if Belongs (Source (J), Set, Test) then |
| return J; |
| end if; |
| end loop; |
| end if; |
| |
| -- Fall through if no match |
| |
| return 0; |
| end Index; |
| |
| --------------------- |
| -- Index_Non_Blank -- |
| --------------------- |
| |
| function Index_Non_Blank |
| (Source : in String; |
| Going : in Direction := Forward) |
| return Natural |
| is |
| begin |
| if Going = Forward then |
| for J in Source'Range loop |
| if Source (J) /= ' ' then |
| return J; |
| end if; |
| end loop; |
| |
| else -- Going = Backward |
| for J in reverse Source'Range loop |
| if Source (J) /= ' ' then |
| return J; |
| end if; |
| end loop; |
| end if; |
| |
| -- Fall through if no match |
| |
| return 0; |
| |
| end Index_Non_Blank; |
| |
| end Ada.Strings.Search; |
