244 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			244 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
var charCodeDef = require('./char-code-definitions');
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var isDigit = charCodeDef.isDigit;
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var isHexDigit = charCodeDef.isHexDigit;
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var isUppercaseLetter = charCodeDef.isUppercaseLetter;
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var isName = charCodeDef.isName;
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var isWhiteSpace = charCodeDef.isWhiteSpace;
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var isValidEscape = charCodeDef.isValidEscape;
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function getCharCode(source, offset) {
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    return offset < source.length ? source.charCodeAt(offset) : 0;
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}
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function getNewlineLength(source, offset, code) {
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    if (code === 13 /* \r */ && getCharCode(source, offset + 1) === 10 /* \n */) {
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        return 2;
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    }
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    return 1;
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}
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function cmpChar(testStr, offset, referenceCode) {
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    var code = testStr.charCodeAt(offset);
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    // code.toLowerCase() for A..Z
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    if (isUppercaseLetter(code)) {
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        code = code | 32;
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    }
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    return code === referenceCode;
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}
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function cmpStr(testStr, start, end, referenceStr) {
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    if (end - start !== referenceStr.length) {
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        return false;
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    }
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    if (start < 0 || end > testStr.length) {
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        return false;
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    }
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    for (var i = start; i < end; i++) {
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        var testCode = testStr.charCodeAt(i);
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        var referenceCode = referenceStr.charCodeAt(i - start);
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        // testCode.toLowerCase() for A..Z
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        if (isUppercaseLetter(testCode)) {
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            testCode = testCode | 32;
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        }
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        if (testCode !== referenceCode) {
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            return false;
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        }
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    }
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    return true;
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}
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function findWhiteSpaceStart(source, offset) {
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    for (; offset >= 0; offset--) {
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        if (!isWhiteSpace(source.charCodeAt(offset))) {
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            break;
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        }
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    }
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    return offset + 1;
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}
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function findWhiteSpaceEnd(source, offset) {
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    for (; offset < source.length; offset++) {
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        if (!isWhiteSpace(source.charCodeAt(offset))) {
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            break;
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        }
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    }
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    return offset;
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}
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function findDecimalNumberEnd(source, offset) {
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    for (; offset < source.length; offset++) {
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        if (!isDigit(source.charCodeAt(offset))) {
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            break;
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        }
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    }
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    return offset;
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}
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// § 4.3.7. Consume an escaped code point
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function consumeEscaped(source, offset) {
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    // It assumes that the U+005C REVERSE SOLIDUS (\) has already been consumed and
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    // that the next input code point has already been verified to be part of a valid escape.
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    offset += 2;
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    // hex digit
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    if (isHexDigit(getCharCode(source, offset - 1))) {
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        // Consume as many hex digits as possible, but no more than 5.
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        // Note that this means 1-6 hex digits have been consumed in total.
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        for (var maxOffset = Math.min(source.length, offset + 5); offset < maxOffset; offset++) {
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            if (!isHexDigit(getCharCode(source, offset))) {
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                break;
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            }
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        }
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        // If the next input code point is whitespace, consume it as well.
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        var code = getCharCode(source, offset);
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        if (isWhiteSpace(code)) {
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            offset += getNewlineLength(source, offset, code);
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        }
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    }
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    return offset;
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}
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// §4.3.11. Consume a name
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// Note: This algorithm does not do the verification of the first few code points that are necessary
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// to ensure the returned code points would constitute an <ident-token>. If that is the intended use,
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// ensure that the stream starts with an identifier before calling this algorithm.
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function consumeName(source, offset) {
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    // Let result initially be an empty string.
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    // Repeatedly consume the next input code point from the stream:
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    for (; offset < source.length; offset++) {
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        var code = source.charCodeAt(offset);
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        // name code point
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        if (isName(code)) {
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            // Append the code point to result.
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            continue;
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        }
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        // the stream starts with a valid escape
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        if (isValidEscape(code, getCharCode(source, offset + 1))) {
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            // Consume an escaped code point. Append the returned code point to result.
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            offset = consumeEscaped(source, offset) - 1;
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            continue;
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        }
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        // anything else
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        // Reconsume the current input code point. Return result.
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        break;
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    }
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    return offset;
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}
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// §4.3.12. Consume a number
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function consumeNumber(source, offset) {
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    var code = source.charCodeAt(offset);
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    // 2. If the next input code point is U+002B PLUS SIGN (+) or U+002D HYPHEN-MINUS (-),
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    // consume it and append it to repr.
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    if (code === 0x002B || code === 0x002D) {
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        code = source.charCodeAt(offset += 1);
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    }
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    // 3. While the next input code point is a digit, consume it and append it to repr.
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    if (isDigit(code)) {
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        offset = findDecimalNumberEnd(source, offset + 1);
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        code = source.charCodeAt(offset);
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    }
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    // 4. If the next 2 input code points are U+002E FULL STOP (.) followed by a digit, then:
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    if (code === 0x002E && isDigit(source.charCodeAt(offset + 1))) {
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        // 4.1 Consume them.
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        // 4.2 Append them to repr.
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        code = source.charCodeAt(offset += 2);
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        // 4.3 Set type to "number".
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        // TODO
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        // 4.4 While the next input code point is a digit, consume it and append it to repr.
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        offset = findDecimalNumberEnd(source, offset);
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    }
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    // 5. If the next 2 or 3 input code points are U+0045 LATIN CAPITAL LETTER E (E)
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    // or U+0065 LATIN SMALL LETTER E (e), ... , followed by a digit, then:
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    if (cmpChar(source, offset, 101 /* e */)) {
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        var sign = 0;
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        code = source.charCodeAt(offset + 1);
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        // ... optionally followed by U+002D HYPHEN-MINUS (-) or U+002B PLUS SIGN (+) ...
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        if (code === 0x002D || code === 0x002B) {
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            sign = 1;
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            code = source.charCodeAt(offset + 2);
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        }
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        // ... followed by a digit
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        if (isDigit(code)) {
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            // 5.1 Consume them.
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            // 5.2 Append them to repr.
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            // 5.3 Set type to "number".
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            // TODO
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            // 5.4 While the next input code point is a digit, consume it and append it to repr.
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            offset = findDecimalNumberEnd(source, offset + 1 + sign + 1);
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        }
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    }
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    return offset;
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}
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// § 4.3.14. Consume the remnants of a bad url
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// ... its sole use is to consume enough of the input stream to reach a recovery point
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// where normal tokenizing can resume.
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function consumeBadUrlRemnants(source, offset) {
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    // Repeatedly consume the next input code point from the stream:
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    for (; offset < source.length; offset++) {
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        var code = source.charCodeAt(offset);
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        // U+0029 RIGHT PARENTHESIS ())
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        // EOF
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        if (code === 0x0029) {
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            // Return.
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            offset++;
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            break;
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        }
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        if (isValidEscape(code, getCharCode(source, offset + 1))) {
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            // Consume an escaped code point.
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            // Note: This allows an escaped right parenthesis ("\)") to be encountered
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            // without ending the <bad-url-token>. This is otherwise identical to
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            // the "anything else" clause.
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            offset = consumeEscaped(source, offset);
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        }
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    }
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    return offset;
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}
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module.exports = {
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    consumeEscaped: consumeEscaped,
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    consumeName: consumeName,
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    consumeNumber: consumeNumber,
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    consumeBadUrlRemnants: consumeBadUrlRemnants,
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    cmpChar: cmpChar,
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    cmpStr: cmpStr,
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    getNewlineLength: getNewlineLength,
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    findWhiteSpaceStart: findWhiteSpaceStart,
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    findWhiteSpaceEnd: findWhiteSpaceEnd
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};
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