[6a3a178] | 1 | var EOF = 0;
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| 2 |
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| 3 | // https://drafts.csswg.org/css-syntax-3/
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| 4 | // § 4.2. Definitions
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| 5 |
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| 6 | // digit
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| 7 | // A code point between U+0030 DIGIT ZERO (0) and U+0039 DIGIT NINE (9).
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| 8 | function isDigit(code) {
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| 9 | return code >= 0x0030 && code <= 0x0039;
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| 10 | }
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| 11 |
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| 12 | // hex digit
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| 13 | // A digit, or a code point between U+0041 LATIN CAPITAL LETTER A (A) and U+0046 LATIN CAPITAL LETTER F (F),
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| 14 | // or a code point between U+0061 LATIN SMALL LETTER A (a) and U+0066 LATIN SMALL LETTER F (f).
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| 15 | function isHexDigit(code) {
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| 16 | return (
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| 17 | isDigit(code) || // 0 .. 9
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| 18 | (code >= 0x0041 && code <= 0x0046) || // A .. F
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| 19 | (code >= 0x0061 && code <= 0x0066) // a .. f
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| 20 | );
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| 21 | }
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| 22 |
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| 23 | // uppercase letter
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| 24 | // A code point between U+0041 LATIN CAPITAL LETTER A (A) and U+005A LATIN CAPITAL LETTER Z (Z).
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| 25 | function isUppercaseLetter(code) {
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| 26 | return code >= 0x0041 && code <= 0x005A;
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| 27 | }
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| 28 |
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| 29 | // lowercase letter
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| 30 | // A code point between U+0061 LATIN SMALL LETTER A (a) and U+007A LATIN SMALL LETTER Z (z).
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| 31 | function isLowercaseLetter(code) {
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| 32 | return code >= 0x0061 && code <= 0x007A;
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| 33 | }
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| 34 |
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| 35 | // letter
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| 36 | // An uppercase letter or a lowercase letter.
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| 37 | function isLetter(code) {
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| 38 | return isUppercaseLetter(code) || isLowercaseLetter(code);
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| 39 | }
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| 40 |
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| 41 | // non-ASCII code point
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| 42 | // A code point with a value equal to or greater than U+0080 <control>.
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| 43 | function isNonAscii(code) {
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| 44 | return code >= 0x0080;
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| 45 | }
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| 46 |
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| 47 | // name-start code point
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| 48 | // A letter, a non-ASCII code point, or U+005F LOW LINE (_).
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| 49 | function isNameStart(code) {
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| 50 | return isLetter(code) || isNonAscii(code) || code === 0x005F;
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| 51 | }
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| 52 |
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| 53 | // name code point
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| 54 | // A name-start code point, a digit, or U+002D HYPHEN-MINUS (-).
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| 55 | function isName(code) {
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| 56 | return isNameStart(code) || isDigit(code) || code === 0x002D;
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| 57 | }
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| 58 |
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| 59 | // non-printable code point
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| 60 | // A code point between U+0000 NULL and U+0008 BACKSPACE, or U+000B LINE TABULATION,
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| 61 | // or a code point between U+000E SHIFT OUT and U+001F INFORMATION SEPARATOR ONE, or U+007F DELETE.
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| 62 | function isNonPrintable(code) {
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| 63 | return (
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| 64 | (code >= 0x0000 && code <= 0x0008) ||
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| 65 | (code === 0x000B) ||
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| 66 | (code >= 0x000E && code <= 0x001F) ||
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| 67 | (code === 0x007F)
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| 68 | );
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| 69 | }
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| 70 |
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| 71 | // newline
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| 72 | // U+000A LINE FEED. Note that U+000D CARRIAGE RETURN and U+000C FORM FEED are not included in this definition,
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| 73 | // as they are converted to U+000A LINE FEED during preprocessing.
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| 74 | // TODO: we doesn't do a preprocessing, so check a code point for U+000D CARRIAGE RETURN and U+000C FORM FEED
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| 75 | function isNewline(code) {
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| 76 | return code === 0x000A || code === 0x000D || code === 0x000C;
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| 77 | }
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| 78 |
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| 79 | // whitespace
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| 80 | // A newline, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
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| 81 | function isWhiteSpace(code) {
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| 82 | return isNewline(code) || code === 0x0020 || code === 0x0009;
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| 83 | }
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| 84 |
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| 85 | // § 4.3.8. Check if two code points are a valid escape
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| 86 | function isValidEscape(first, second) {
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| 87 | // If the first code point is not U+005C REVERSE SOLIDUS (\), return false.
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| 88 | if (first !== 0x005C) {
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| 89 | return false;
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| 90 | }
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| 91 |
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| 92 | // Otherwise, if the second code point is a newline or EOF, return false.
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| 93 | if (isNewline(second) || second === EOF) {
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| 94 | return false;
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| 95 | }
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| 96 |
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| 97 | // Otherwise, return true.
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| 98 | return true;
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| 99 | }
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| 100 |
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| 101 | // § 4.3.9. Check if three code points would start an identifier
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| 102 | function isIdentifierStart(first, second, third) {
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| 103 | // Look at the first code point:
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| 104 |
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| 105 | // U+002D HYPHEN-MINUS
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| 106 | if (first === 0x002D) {
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| 107 | // If the second code point is a name-start code point or a U+002D HYPHEN-MINUS,
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| 108 | // or the second and third code points are a valid escape, return true. Otherwise, return false.
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| 109 | return (
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| 110 | isNameStart(second) ||
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| 111 | second === 0x002D ||
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| 112 | isValidEscape(second, third)
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| 113 | );
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| 114 | }
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| 115 |
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| 116 | // name-start code point
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| 117 | if (isNameStart(first)) {
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| 118 | // Return true.
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| 119 | return true;
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| 120 | }
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| 121 |
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| 122 | // U+005C REVERSE SOLIDUS (\)
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| 123 | if (first === 0x005C) {
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| 124 | // If the first and second code points are a valid escape, return true. Otherwise, return false.
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| 125 | return isValidEscape(first, second);
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| 126 | }
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| 127 |
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| 128 | // anything else
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| 129 | // Return false.
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| 130 | return false;
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| 131 | }
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| 132 |
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| 133 | // § 4.3.10. Check if three code points would start a number
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| 134 | function isNumberStart(first, second, third) {
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| 135 | // Look at the first code point:
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| 136 |
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| 137 | // U+002B PLUS SIGN (+)
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| 138 | // U+002D HYPHEN-MINUS (-)
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| 139 | if (first === 0x002B || first === 0x002D) {
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| 140 | // If the second code point is a digit, return true.
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| 141 | if (isDigit(second)) {
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| 142 | return 2;
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| 143 | }
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| 144 |
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| 145 | // Otherwise, if the second code point is a U+002E FULL STOP (.)
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| 146 | // and the third code point is a digit, return true.
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| 147 | // Otherwise, return false.
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| 148 | return second === 0x002E && isDigit(third) ? 3 : 0;
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| 149 | }
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| 150 |
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| 151 | // U+002E FULL STOP (.)
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| 152 | if (first === 0x002E) {
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| 153 | // If the second code point is a digit, return true. Otherwise, return false.
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| 154 | return isDigit(second) ? 2 : 0;
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| 155 | }
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| 156 |
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| 157 | // digit
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| 158 | if (isDigit(first)) {
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| 159 | // Return true.
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| 160 | return 1;
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| 161 | }
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| 162 |
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| 163 | // anything else
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| 164 | // Return false.
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| 165 | return 0;
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| 166 | }
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| 167 |
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| 168 | //
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| 169 | // Misc
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| 170 | //
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| 171 |
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| 172 | // detect BOM (https://en.wikipedia.org/wiki/Byte_order_mark)
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| 173 | function isBOM(code) {
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| 174 | // UTF-16BE
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| 175 | if (code === 0xFEFF) {
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| 176 | return 1;
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| 177 | }
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| 178 |
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| 179 | // UTF-16LE
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| 180 | if (code === 0xFFFE) {
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| 181 | return 1;
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| 182 | }
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| 183 |
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| 184 | return 0;
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| 185 | }
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| 186 |
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| 187 | // Fast code category
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| 188 | //
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| 189 | // https://drafts.csswg.org/css-syntax/#tokenizer-definitions
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| 190 | // > non-ASCII code point
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| 191 | // > A code point with a value equal to or greater than U+0080 <control>
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| 192 | // > name-start code point
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| 193 | // > A letter, a non-ASCII code point, or U+005F LOW LINE (_).
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| 194 | // > name code point
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| 195 | // > A name-start code point, a digit, or U+002D HYPHEN-MINUS (-)
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| 196 | // That means only ASCII code points has a special meaning and we define a maps for 0..127 codes only
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| 197 | var CATEGORY = new Array(0x80);
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| 198 | charCodeCategory.Eof = 0x80;
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| 199 | charCodeCategory.WhiteSpace = 0x82;
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| 200 | charCodeCategory.Digit = 0x83;
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| 201 | charCodeCategory.NameStart = 0x84;
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| 202 | charCodeCategory.NonPrintable = 0x85;
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| 203 |
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| 204 | for (var i = 0; i < CATEGORY.length; i++) {
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| 205 | switch (true) {
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| 206 | case isWhiteSpace(i):
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| 207 | CATEGORY[i] = charCodeCategory.WhiteSpace;
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| 208 | break;
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| 209 |
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| 210 | case isDigit(i):
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| 211 | CATEGORY[i] = charCodeCategory.Digit;
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| 212 | break;
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| 213 |
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| 214 | case isNameStart(i):
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| 215 | CATEGORY[i] = charCodeCategory.NameStart;
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| 216 | break;
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| 217 |
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| 218 | case isNonPrintable(i):
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| 219 | CATEGORY[i] = charCodeCategory.NonPrintable;
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| 220 | break;
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| 221 |
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| 222 | default:
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| 223 | CATEGORY[i] = i || charCodeCategory.Eof;
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| 224 | }
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| 225 | }
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| 226 |
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| 227 | function charCodeCategory(code) {
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| 228 | return code < 0x80 ? CATEGORY[code] : charCodeCategory.NameStart;
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| 229 | };
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| 230 |
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| 231 | module.exports = {
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| 232 | isDigit: isDigit,
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| 233 | isHexDigit: isHexDigit,
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| 234 | isUppercaseLetter: isUppercaseLetter,
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| 235 | isLowercaseLetter: isLowercaseLetter,
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| 236 | isLetter: isLetter,
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| 237 | isNonAscii: isNonAscii,
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| 238 | isNameStart: isNameStart,
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| 239 | isName: isName,
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| 240 | isNonPrintable: isNonPrintable,
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| 241 | isNewline: isNewline,
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| 242 | isWhiteSpace: isWhiteSpace,
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| 243 | isValidEscape: isValidEscape,
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| 244 | isIdentifierStart: isIdentifierStart,
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| 245 | isNumberStart: isNumberStart,
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| 246 |
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| 247 | isBOM: isBOM,
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| 248 | charCodeCategory: charCodeCategory
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| 249 | };
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