stringencoding
Version:
Encode to/from Typed Array buffers
81 lines (77 loc) • 2.48 kB
JavaScript
// 11.1 euc.jp
/**
* @constructor
* @param {{fatal: boolean}} options
*/
function EUCJPDecoder(options) {
var fatal = options.fatal;
var /** @type {number} */ eucjp_first = 0x00,
/** @type {number} */ eucjp_second = 0x00;
/**
* @param {ByteInputStream} byte_pointer The byte stream to decode.
* @return {?number} The next code point decoded, or null if not enough
* data exists in the input stream to decode a complete code point.
*/
this.decode = function(byte_pointer) {
var bite = byte_pointer.get();
if (bite === EOF_byte) {
if (eucjp_first === 0x00 && eucjp_second === 0x00) {
return EOF_code_point;
}
eucjp_first = 0x00;
eucjp_second = 0x00;
return decoderError(fatal);
}
byte_pointer.offset(1);
var lead, code_point;
if (eucjp_second !== 0x00) {
lead = eucjp_second;
eucjp_second = 0x00;
code_point = null;
if (inRange(lead, 0xA1, 0xFE) && inRange(bite, 0xA1, 0xFE)) {
code_point = indexCodePointFor((lead - 0xA1) * 94 + bite - 0xA1,
indexes['jis0212']);
}
if (!inRange(bite, 0xA1, 0xFE)) {
byte_pointer.offset(-1);
}
if (code_point === null) {
return decoderError(fatal);
}
return code_point;
}
if (eucjp_first === 0x8E && inRange(bite, 0xA1, 0xDF)) {
eucjp_first = 0x00;
return 0xFF61 + bite - 0xA1;
}
if (eucjp_first === 0x8F && inRange(bite, 0xA1, 0xFE)) {
eucjp_first = 0x00;
eucjp_second = bite;
return null;
}
if (eucjp_first !== 0x00) {
lead = eucjp_first;
eucjp_first = 0x00;
code_point = null;
if (inRange(lead, 0xA1, 0xFE) && inRange(bite, 0xA1, 0xFE)) {
code_point = indexCodePointFor((lead - 0xA1) * 94 + bite - 0xA1,
indexes['jis0208']);
}
if (!inRange(bite, 0xA1, 0xFE)) {
byte_pointer.offset(-1);
}
if (code_point === null) {
return decoderError(fatal);
}
return code_point;
}
if (inRange(bite, 0x00, 0x7F)) {
return bite;
}
if (bite === 0x8E || bite === 0x8F || (inRange(bite, 0xA1, 0xFE))) {
eucjp_first = bite;
return null;
}
return decoderError(fatal);
};
}