1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009 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 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. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- Note: this package uses the generic subprograms in System.Wch_Cnv, which
33 -- completely encapsulate the set of wide character encoding methods, so no
34 -- modifications are required when adding new encoding methods.
38 with System.WCh_Cnv; use System.WCh_Cnv;
39 with System.WCh_Con; use System.WCh_Con;
41 package body Widechar is
43 ---------------------------
44 -- Is_Start_Of_Wide_Char --
45 ---------------------------
47 function Is_Start_Of_Wide_Char
48 (S : Source_Buffer_Ptr;
49 P : Source_Ptr) return Boolean
52 case Wide_Character_Encoding_Method is
54 -- For Hex mode, just test for an ESC character. The ESC character
55 -- cannot appear in any other context in a legal Ada program.
58 return S (P) = ASCII.ESC;
60 -- For brackets, just test ["x where x is a hex character. This is
61 -- sufficient test, since this sequence cannot otherwise appear in a
65 return P <= S'Last - 2
67 and then S (P + 1) = '"'
68 and then (S (P + 2) in '0' .. '9'
70 S (P + 2) in 'a' .. 'f'
72 S (P + 2) in 'A' .. 'F');
74 -- All other encoding methods use the upper bit set in the first
75 -- character to uniquely represent a wide character.
81 return S (P) >= Character'Val (16#80#);
83 end Is_Start_Of_Wide_Char;
89 function Length_Wide return Nat is
91 return WC_Longest_Sequence;
99 (S : Source_Buffer_Ptr;
100 P : in out Source_Ptr;
104 P_Init : constant Source_Ptr := P;
107 function In_Char return Character;
108 -- Function to obtain characters of wide character escape sequence
114 function In_Char return Character is
120 function WC_In is new Char_Sequence_To_UTF_32 (In_Char);
122 -- Start of processing for Scan_Wide
127 -- Scan out the wide character. If the first character is a bracket,
128 -- we allow brackets encoding regardless of the standard encoding
129 -- method being used, but otherwise we use this standard method.
132 C := Char_Code (WC_In (Chr, WCEM_Brackets));
134 C := Char_Code (WC_In (Chr, Wide_Character_Encoding_Method));
138 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
141 when Constraint_Error =>
156 procedure Out_Char (C : Character);
157 -- Procedure to store one character of wide character sequence
163 procedure Out_Char (C : Character) is
169 procedure WC_Out is new UTF_32_To_Char_Sequence (Out_Char);
171 -- Start of processing for Set_Wide
174 WC_Out (UTF_32_Code (C), Wide_Character_Encoding_Method);
181 procedure Skip_Wide (S : String; P : in out Natural) is
182 P_Init : constant Natural := P;
184 function Skip_Char return Character;
185 -- Function to skip one character of wide character escape sequence
191 function Skip_Char return Character is
197 function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
199 Discard : UTF_32_Code;
200 pragma Warnings (Off, Discard);
202 -- Start of processing for Skip_Wide
205 Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
206 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);
213 procedure Skip_Wide (S : Source_Buffer_Ptr; P : in out Source_Ptr) is
214 P_Init : constant Source_Ptr := P;
216 function Skip_Char return Character;
217 -- Function to skip one character of wide character escape sequence
223 function Skip_Char return Character is
229 function WC_Skip is new Char_Sequence_To_UTF_32 (Skip_Char);
231 Discard : UTF_32_Code;
232 pragma Warnings (Off, Discard);
234 -- Start of processing for Skip_Wide
237 Discard := WC_Skip (Skip_Char, Wide_Character_Encoding_Method);
238 Wide_Char_Byte_Count := Wide_Char_Byte_Count + Nat (P - P_Init - 1);