mirror of git://git.acid.vegas/asciiblaster.git
142 lines
3.4 KiB
JavaScript
142 lines
3.4 KiB
JavaScript
// taken from https://github.com/coolaj86/TextEncoderLite/blob/master/index.js
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// added polyfill at bottom
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function TextEncoderLite() {
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}
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function TextDecoderLite() {
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}
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(function () {
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'use strict';
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// Taken from https://github.com/feross/buffer/blob/master/index.js
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// Thanks Feross et al! :-)
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function utf8ToBytes (string, units) {
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units = units || Infinity
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var codePoint
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var length = string.length
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var leadSurrogate = null
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var bytes = []
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var i = 0
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for (; i < length; i++) {
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codePoint = string.charCodeAt(i)
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// is surrogate component
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if (codePoint > 0xD7FF && codePoint < 0xE000) {
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// last char was a lead
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if (leadSurrogate) {
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// 2 leads in a row
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if (codePoint < 0xDC00) {
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if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
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leadSurrogate = codePoint
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continue
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} else {
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// valid surrogate pair
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codePoint = leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00 | 0x10000
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leadSurrogate = null
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}
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} else {
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// no lead yet
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if (codePoint > 0xDBFF) {
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// unexpected trail
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if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
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continue
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} else if (i + 1 === length) {
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// unpaired lead
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if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
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continue
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} else {
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// valid lead
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leadSurrogate = codePoint
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continue
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}
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}
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} else if (leadSurrogate) {
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// valid bmp char, but last char was a lead
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if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
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leadSurrogate = null
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}
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// encode utf8
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if (codePoint < 0x80) {
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if ((units -= 1) < 0) break
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bytes.push(codePoint)
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} else if (codePoint < 0x800) {
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if ((units -= 2) < 0) break
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bytes.push(
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codePoint >> 0x6 | 0xC0,
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codePoint & 0x3F | 0x80
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)
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} else if (codePoint < 0x10000) {
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if ((units -= 3) < 0) break
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bytes.push(
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codePoint >> 0xC | 0xE0,
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codePoint >> 0x6 & 0x3F | 0x80,
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codePoint & 0x3F | 0x80
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)
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} else if (codePoint < 0x200000) {
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if ((units -= 4) < 0) break
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bytes.push(
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codePoint >> 0x12 | 0xF0,
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codePoint >> 0xC & 0x3F | 0x80,
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codePoint >> 0x6 & 0x3F | 0x80,
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codePoint & 0x3F | 0x80
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)
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} else {
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throw new Error('Invalid code point')
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}
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}
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return bytes
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}
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function utf8Slice (buf, start, end) {
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var res = ''
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var tmp = ''
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end = Math.min(buf.length, end || Infinity)
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start = start || 0;
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for (var i = start; i < end; i++) {
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if (buf[i] <= 0x7F) {
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res += decodeUtf8Char(tmp) + String.fromCharCode(buf[i])
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tmp = ''
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} else {
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tmp += '%' + buf[i].toString(16)
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}
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}
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return res + decodeUtf8Char(tmp)
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}
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function decodeUtf8Char (str) {
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try {
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return decodeURIComponent(str)
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} catch (err) {
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return String.fromCharCode(0xFFFD) // UTF 8 invalid char
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}
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}
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TextEncoderLite.prototype.encode = function (str) {
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var result;
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if ('undefined' === typeof Uint8Array) {
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result = utf8ToBytes(str);
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} else {
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result = new Uint8Array(utf8ToBytes(str));
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}
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return result;
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};
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TextDecoderLite.prototype.decode = function (bytes) {
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return utf8Slice(bytes, 0, bytes.length);
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}
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}());
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if (typeof TextEncoder === 'undefined') TextEncoder = TextEncoderLite
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if (typeof TextDecoder === 'undefined') TextDecoder = TextDecoderLite
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