1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
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. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- Note: this package uses the generic subprograms in System.Wch_Cnv, which
35 -- completely encapsulate the set of wide character encoding methods, so no
36 -- modifications are required when adding new encoding methods.
40 with System.WCh_Cnv; use System.WCh_Cnv;
41 with System.WCh_Con; use System.WCh_Con;
43 package body Widechar is
45 ---------------------------
46 -- Is_Start_Of_Wide_Char --
47 ---------------------------
49 function Is_Start_Of_Wide_Char
50 (S : Source_Buffer_Ptr;
51 P : Source_Ptr) return Boolean
54 case Wide_Character_Encoding_Method is
56 -- For Hex mode, just test for an ESC character. The ESC character
57 -- cannot appear in any other context in a legal Ada program.
60 return S (P) = ASCII.ESC;
62 -- For brackets, just test ["x where x is a hex character. This is
63 -- sufficient test, since this sequence cannot otherwise appear in a
67 return P <= S'Last - 2
69 and then S (P + 1) = '"'
70 and then (S (P + 2) in '0' .. '9'
72 S (P + 2) in 'a' .. 'f'
74 S (P + 2) in 'A' .. 'F');
76 -- All other encoding methods use the upper bit set in the first
77 -- character to uniquely represent a wide character.
83 return S (P) >= Character'Val (16#80#);
85 end Is_Start_Of_Wide_Char;
91 function Length_Wide return Nat is
93 return WC_Longest_Sequence;
101 (S : Source_Buffer_Ptr;
102 P : in out Source_Ptr;
106 P_Init : constant Source_Ptr := P;
109 function In_Char return Character;
110 -- Function to obtain characters of wide character escape sequence
116 function In_Char return Character is
122 function WC_In is new Char_Sequence_To_UTF_32 (In_Char);
124 -- Start of processingf for Scan_Wide
129 -- Scan out the wide character. if the first character is a bracket,
130 -- we allow brackets encoding regardless of the standard encoding
131 -- method being used, but otherwise we use this standard method.
134 C := Char_Code (WC_In (Chr, WCEM_Brackets));
136 C := Char_Code (WC_In (Chr, Wide_Character_Encoding_Method));
140 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
143 when Constraint_Error =>
158 procedure Out_Char (C : Character);
159 -- Procedure to store one character of wide character sequence
165 procedure Out_Char (C : Character) is
171 procedure WC_Out is new UTF_32_To_Char_Sequence (Out_Char);
173 -- Start of processing for Set_Wide
176 WC_Out (UTF_32_Code (C), Wide_Character_Encoding_Method);
183 procedure Skip_Wide (S : String; P : in out Natural) is
184 P_Init : constant Natural := P;
186 function Skip_Char return Character;
187 -- Function to skip one character of wide character escape sequence
193 function Skip_Char return Character is
199 function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
201 Discard : UTF_32_Code;
202 pragma Warnings (Off, Discard);
204 -- Start of processing for Skip_Wide
207 Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
208 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
215 procedure Skip_Wide (S : Source_Buffer_Ptr; P : in out Source_Ptr) is
216 P_Init : constant Source_Ptr := P;
218 function Skip_Char return Character;
219 -- Function to skip one character of wide character escape sequence
225 function Skip_Char return Character is
231 function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
233 Discard : UTF_32_Code;
234 pragma Warnings (Off, Discard);
236 -- Start of processing for Skip_Wide
239 Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
240 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);