dmdscript.utf source code

1 /*
2  * Excert from Phobos standart library for D2, this one uses immutable destanation string
3 */
4 module dmdscript.utf;
5 public import std.utf;
6 
7 ///encodes dchar ch and appends it to array s
8 void encode(ref immutable(char)[] s, dchar c)
9 {
10     immutable(char)[] r = s;
11 
12     if(c <= 0x7F)
13     {
14         assert(isValidDchar(c));
15         r ~= cast(char)c;
16     }
17     else
18     {
19         char[4] buf;
20         uint L;
21 
22         if(c <= 0x7FF)
23         {
24             assert(isValidDchar(c));
25             buf[0] = cast(char)(0xC0 | (c >> 6));
26             buf[1] = cast(char)(0x80 | (c & 0x3F));
27             L = 2;
28         }
29         else if(c <= 0xFFFF)
30         {
31             if(0xD800 <= c && c <= 0xDFFF)
32                 throw new UTFException(
33                     "encoding a surrogate code point in UTF-8", c);
34             assert(isValidDchar(c));
35             buf[0] = cast(char)(0xE0 | (c >> 12));
36             buf[1] = cast(char)(0x80 | ((c >> 6) & 0x3F));
37             buf[2] = cast(char)(0x80 | (c & 0x3F));
38             L = 3;
39         }
40         else if(c <= 0x10FFFF)
41         {
42             assert(isValidDchar(c));
43             buf[0] = cast(char)(0xF0 | (c >> 18));
44             buf[1] = cast(char)(0x80 | ((c >> 12) & 0x3F));
45             buf[2] = cast(char)(0x80 | ((c >> 6) & 0x3F));
46             buf[3] = cast(char)(0x80 | (c & 0x3F));
47             L = 4;
48         }
49         else
50         {
51             assert(!isValidDchar(c));
52             throw new UTFException(
53                 "encoding an invalid code point in UTF-8", c);
54         }
55         r ~= buf[0 .. L];
56     }
57     s = r;
58 }