var isHexDigit = require('../../tokenizer').isHexDigit; var cmpChar = require('../../tokenizer').cmpChar; var TYPE = require('../../tokenizer').TYPE; var NAME = require('../../tokenizer').NAME; var CHARCODE = require('../../tokenizer').CHARCODE; var IDENT = TYPE.Ident; var NUMBER = TYPE.Number; var DIMENSION = TYPE.Dimension; var PLUSSIGN = CHARCODE.PlusSign; var HYPHENMINUS = CHARCODE.HyphenMinus; var QUESTIONMARK = CHARCODE.QuestionMark; var U = 117; // 'u'.charCodeAt() function eatHexSequence(offset, allowDash) { for (var pos = this.scanner.tokenStart + offset, len = 0; pos < this.scanner.tokenEnd; pos++) { var code = this.scanner.source.charCodeAt(pos); if (code === HYPHENMINUS && allowDash && len !== 0) { if (eatHexSequence.call(this, offset + len + 1, false) === 0) { this.error(); } return -1; } if (!isHexDigit(code)) { this.error( allowDash && len !== 0 ? 'HyphenMinus' + (len < 6 ? ' or hex digit' : '') + ' is expected' : (len < 6 ? 'Hex digit is expected' : 'Unexpected input'), pos ); } if (++len > 6) { this.error('Too many hex digits', pos); }; } this.scanner.next(); return len; } function eatQuestionMarkSequence(max) { var count = 0; while (this.scanner.isDelim(QUESTIONMARK)) { if (++count > max) { this.error('Too many question marks'); } this.scanner.next(); } } function startsWith(code) { if (this.scanner.source.charCodeAt(this.scanner.tokenStart) !== code) { this.error(NAME[code] + ' is expected'); } } // https://drafts.csswg.org/css-syntax/#urange // Informally, the production has three forms: // U+0001 // Defines a range consisting of a single code point, in this case the code point "1". // U+0001-00ff // Defines a range of codepoints between the first and the second value, in this case // the range between "1" and "ff" (255 in decimal) inclusive. // U+00?? // Defines a range of codepoints where the "?" characters range over all hex digits, // in this case defining the same as the value U+0000-00ff. // In each form, a maximum of 6 digits is allowed for each hexadecimal number (if you treat "?" as a hexadecimal digit). // // = // u '+' '?'* | // u '?'* | // u '?'* | // u | // u | // u '+' '?'+ function scanUnicodeRange() { var hexLength = 0; // u '+' '?'* // u '+' '?'+ if (this.scanner.isDelim(PLUSSIGN)) { this.scanner.next(); if (this.scanner.tokenType === IDENT) { hexLength = eatHexSequence.call(this, 0, true); if (hexLength > 0) { eatQuestionMarkSequence.call(this, 6 - hexLength); } return; } if (this.scanner.isDelim(QUESTIONMARK)) { this.scanner.next(); eatQuestionMarkSequence.call(this, 5); return; } this.error('Hex digit or question mark is expected'); return; } // u '?'* // u // u if (this.scanner.tokenType === NUMBER) { startsWith.call(this, PLUSSIGN); hexLength = eatHexSequence.call(this, 1, true); if (this.scanner.isDelim(QUESTIONMARK)) { eatQuestionMarkSequence.call(this, 6 - hexLength); return; } if (this.scanner.tokenType === DIMENSION || this.scanner.tokenType === NUMBER) { startsWith.call(this, HYPHENMINUS); eatHexSequence.call(this, 1, false); return; } return; } // u '?'* if (this.scanner.tokenType === DIMENSION) { startsWith.call(this, PLUSSIGN); hexLength = eatHexSequence.call(this, 1, true); if (hexLength > 0) { eatQuestionMarkSequence.call(this, 6 - hexLength); } return; } this.error(); } module.exports = { name: 'UnicodeRange', structure: { value: String }, parse: function() { var start = this.scanner.tokenStart; // U or u if (!cmpChar(this.scanner.source, start, U)) { this.error('U is expected'); } if (!cmpChar(this.scanner.source, start + 1, PLUSSIGN)) { this.error('Plus sign is expected'); } this.scanner.next(); scanUnicodeRange.call(this); return { type: 'UnicodeRange', loc: this.getLocation(start, this.scanner.tokenStart), value: this.scanner.substrToCursor(start) }; }, generate: function(node) { this.chunk(node.value); } };