File : s-wchstw.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- S Y S T E M . W C H _ S T W --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2009, 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 -- --
19 -- --
20 -- --
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 System.WCh_Con; use System.WCh_Con;
33 with System.WCh_Cnv; use System.WCh_Cnv;
34
35 package body System.WCh_StW is
36
37 -----------------------
38 -- Local Subprograms --
39 -----------------------
40
41 procedure Get_Next_Code
42 (S : String;
43 P : in out Natural;
44 V : out UTF_32_Code;
45 EM : WC_Encoding_Method);
46 -- Scans next character starting at S(P) and returns its value in V. On
47 -- exit P is updated past the last character read. Raises Constraint_Error
48 -- if the string is not well formed. Raises Constraint_Error if the code
49 -- value is greater than 16#7FFF_FFFF#. On entry P <= S'Last.
50
51 -------------------
52 -- Get_Next_Code --
53 -------------------
54
55 procedure Get_Next_Code
56 (S : String;
57 P : in out Natural;
58 V : out UTF_32_Code;
59 EM : WC_Encoding_Method)
60 is
61 function In_Char return Character;
62 -- Function to return a character, bumping P, raises Constraint_Error
63 -- if P > S'Last on entry.
64
65 function Get_UTF_32 is new Char_Sequence_To_UTF_32 (In_Char);
66 -- Function to get next UFT_32 value
67
68 -------------
69 -- In_Char --
70 -------------
71
72 function In_Char return Character is
73 begin
74 if P > S'Last then
75 raise Constraint_Error with "badly formed wide character code";
76 else
77 P := P + 1;
78 return S (P - 1);
79 end if;
80 end In_Char;
81
82 -- Start of processing for Get_Next_Code
83
84 begin
85 -- Check for wide character encoding
86
87 case EM is
88 when WCEM_Hex =>
89 if S (P) = ASCII.ESC then
90 V := Get_UTF_32 (In_Char, EM);
91 return;
92 end if;
93
94 when WCEM_Upper | WCEM_Shift_JIS | WCEM_EUC | WCEM_UTF8 =>
95 if S (P) >= Character'Val (16#80#) then
96 V := Get_UTF_32 (In_Char, EM);
97 return;
98 end if;
99
100 when WCEM_Brackets =>
101 if P + 2 <= S'Last
102 and then S (P) = '['
103 and then S (P + 1) = '"'
104 and then S (P + 2) /= '"'
105 then
106 V := Get_UTF_32 (In_Char, EM);
107 return;
108 end if;
109 end case;
110
111 -- If it is not a wide character code, just get it
112
113 V := Character'Pos (S (P));
114 P := P + 1;
115 end Get_Next_Code;
116
117 ---------------------------
118 -- String_To_Wide_String --
119 ---------------------------
120
121 procedure String_To_Wide_String
122 (S : String;
123 R : out Wide_String;
124 L : out Natural;
125 EM : System.WCh_Con.WC_Encoding_Method)
126 is
127 SP : Natural;
128 V : UTF_32_Code;
129
130 begin
131 pragma Assert (S'First = 1);
132
133 SP := S'First;
134 L := 0;
135 while SP <= S'Last loop
136 Get_Next_Code (S, SP, V, EM);
137
138 if V > 16#FFFF# then
139 raise Constraint_Error with
140 "out of range value for wide character";
141 end if;
142
143 L := L + 1;
144 R (L) := Wide_Character'Val (V);
145 end loop;
146 end String_To_Wide_String;
147
148 --------------------------------
149 -- String_To_Wide_Wide_String --
150 --------------------------------
151
152 procedure String_To_Wide_Wide_String
153 (S : String;
154 R : out Wide_Wide_String;
155 L : out Natural;
156 EM : System.WCh_Con.WC_Encoding_Method)
157 is
158 pragma Assert (S'First = 1);
159
160 SP : Natural;
161 V : UTF_32_Code;
162
163 begin
164 SP := S'First;
165 L := 0;
166 while SP <= S'Last loop
167 Get_Next_Code (S, SP, V, EM);
168 L := L + 1;
169 R (L) := Wide_Wide_Character'Val (V);
170 end loop;
171 end String_To_Wide_Wide_String;
172
173 end System.WCh_StW;