Mercurial > projects > dil
view trunk/src/dil/Unicode.d @ 518:8f86bb9ef715
Added module dil.Converter and dil.FileBOM.
Moved code from dil.File to dil.FileBOM.
Added opCatAssign to class InformationManager.
Added encode() function to dil.Unicode.
author | Aziz K?ksal <aziz.koeksal@gmail.com> |
---|---|
date | Sat, 15 Dec 2007 18:55:06 +0100 |
parents | dd3ce87b3569 |
children | d050e211402b |
line wrap: on
line source
/++ Author: Aziz Köksal License: GPL3 +/ module dil.Unicode; public import std.uni : isUniAlpha; /// U+FFFD = �. Used to replace invalid Unicode characters. const dchar REPLACEMENT_CHAR = '\uFFFD'; /// Invalid character, returned on errors. const dchar ERROR_CHAR = 0xD800; /++ Returns true if this character is not a surrogate code point and not higher than 0x10FFFF. +/ bool isValidChar(dchar d) { return d < 0xD800 || d > 0xDFFF && d <= 0x10FFFF; } /++ Returns true if this is one of the There are a total of 66 noncharacters. See_also: Chapter 16.7 Noncharacters in Unicode 5.0 +/ bool isNoncharacter(dchar d) { return 0xFDD0 <= d && d <= 0xFDEF || // 32 d <= 0x10FFFF && (d & 0xFFFF) >= 0xFFFE; // 34 } /// Returns true if this is a trail byte of a UTF-8 sequence? bool isTrailByte(ubyte b) { return (b & 0xC0) == 0x80; // 10xx_xxxx } /// Returns true if this is a lead byte of a UTF-8 sequence. bool isLeadByte(ubyte b) { return (b & 0xC0) == 0xC0; // 11xx_xxxx } dchar decode(char[] str, ref size_t index) in { assert(str.length); } out(c) { assert(isValidChar(c)); } body { char* p = str.ptr + index; char* end = str.ptr + str.length; dchar c = *p; if (!(p < end)) return ERROR_CHAR; if (c < 0x80) { ++index; return c; } ++p; // Move to second byte. if (!(p < end)) return ERROR_CHAR; // Error if second byte is not a trail byte. if (!isTrailByte(*p)) return ERROR_CHAR; // Check for overlong sequences. switch (c) { case 0xE0, // 11100000 100xxxxx 0xF0, // 11110000 1000xxxx 0xF8, // 11111000 10000xxx 0xFC: // 11111100 100000xx if ((*p & c) == 0x80) return ERROR_CHAR; default: if ((c & 0xFE) == 0xC0) // 1100000x return ERROR_CHAR; } const char[] checkNextByte = "if (++p < end && !isTrailByte(*p))" " return ERROR_CHAR;"; const char[] appendSixBits = "c = (c << 6) | *p & 0b0011_1111;"; auto next_index = index; // Decode if ((c & 0b1110_0000) == 0b1100_0000) { // 110xxxxx 10xxxxxx c &= 0b0001_1111; mixin(appendSixBits); next_index += 2; } else if ((c & 0b1111_0000) == 0b1110_0000) { // 1110xxxx 10xxxxxx 10xxxxxx c &= 0b0000_1111; mixin(appendSixBits ~ checkNextByte ~ appendSixBits); next_index += 3; } else if ((c & 0b1111_1000) == 0b1111_0000) { // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx c &= 0b0000_0111; mixin(appendSixBits ~ checkNextByte ~ appendSixBits ~ checkNextByte ~ appendSixBits); next_index += 4; } else // 5 and 6 byte UTF-8 sequences are not allowed yet. // 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx // 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx return ERROR_CHAR; assert(isTrailByte(*p)); if (!isValidChar(c)) return ERROR_CHAR; index = next_index; return c; } /// Encodes a character and appends it to str. void encode(ref char[] str, dchar c) { assert(isValidChar(c), "check if character is valid before calling encode()."); char[6] b = void; if (c < 0x80) str ~= c; if (c < 0x800) { b[0] = 0xC0 | (c >> 6); b[1] = 0x80 | (c & 0x3F); str ~= b[0..2]; } else if (c < 0x10000) { b[0] = 0xE0 | (c >> 12); b[1] = 0x80 | ((c >> 6) & 0x3F); b[2] = 0x80 | (c & 0x3F); str ~= b[0..3]; } else if (c < 0x200000) { b[0] = 0xF0 | (c >> 18); b[1] = 0x80 | ((c >> 12) & 0x3F); b[2] = 0x80 | ((c >> 6) & 0x3F); b[3] = 0x80 | (c & 0x3F); str ~= b[0..4]; } /+ // There are no 5 and 6 byte UTF-8 sequences yet. else if (c < 0x4000000) { b[0] = 0xF8 | (c >> 24); b[1] = 0x80 | ((c >> 18) & 0x3F); b[2] = 0x80 | ((c >> 12) & 0x3F); b[3] = 0x80 | ((c >> 6) & 0x3F); b[4] = 0x80 | (c & 0x3F); str ~= b[0..5]; } else if (c < 0x80000000) { b[0] = 0xFC | (c >> 30); b[1] = 0x80 | ((c >> 24) & 0x3F); b[2] = 0x80 | ((c >> 18) & 0x3F); b[3] = 0x80 | ((c >> 12) & 0x3F); b[4] = 0x80 | ((c >> 6) & 0x3F); b[5] = 0x80 | (c & 0x3F); str ~= b[0..6]; } +/ else assert(0); } /// Encodes a character and appends it to str. void encode(ref wchar[] str, dchar c) in { assert(isValidChar(c)); } body { if (c < 0x10000) str ~= cast(wchar)c; else { // Encode with surrogate pair. wchar[2] pair = void; c -= 0x10000; // c' // higher10bits(c') | 0b1101_10xx_xxxx_xxxx pair[0] = (c >> 10) | 0xD800; // lower10bits(c') | 0b1101_11yy_yyyy_yyyy pair[1] = (c & 0x3FF) | 0xDC00; str ~= pair; } } /++ Returns a decoded character from a UTF-16 sequence. In case of an error in the sequence 0xD800 is returned. Params: str = the UTF-16 sequence. index = where to start from. +/ dchar decode(wchar[] str, ref size_t index) { assert(str.length && index < str.length); dchar c = str[index]; if (0xD800 > c || c > 0xDFFF) { ++index; return c; } if (c <= 0xDBFF && index+1 != str.length) { wchar c2 = str[index+1]; if (0xDC00 <= c2 && c2 <= 0xDFFF) { // (c - 0xD800) << 10 + 0x10000 -> // (c - 0xD800 + 0x40) << 10 -> c = (c - 0xD7C0) << 10; c |= (c2 & 0x3FF); index += 2; return c; } } return ERROR_CHAR; } /++ Returns a decoded character from a UTF-16 sequence. In case of an error in the sequence 0xD800 is returned. Params: p = start of the UTF-16 sequence. end = one past the end of the sequence. +/ dchar decode(ref wchar* p, wchar* end) { assert(p && p < end); dchar c = *p; if (0xD800 > c || c > 0xDFFF) { ++p; return c; } if (c <= 0xDBFF && p+1 != end) { wchar c2 = p[1]; if (0xDC00 <= c2 && c2 <= 0xDFFF) { c = (c - 0xD7C0) << 10; c |= (c2 & 0x3FF); p += 2; return c; } } return ERROR_CHAR; } /// Decode a character from a zero-terminated string. dchar decode(ref wchar* p) { assert(p); dchar c = *p; if (0xD800 > c || c > 0xDFFF) { ++p; return c; } if (c <= 0xDBFF) { wchar c2 = p[1]; if (0xDC00 <= c2 && c2 <= 0xDFFF) { c = (c - 0xD7C0) << 10; c |= (c2 & 0x3FF); p += 2; return c; } } return ERROR_CHAR; }