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var isDigit = require('../../tokenizer').isDigit; var TYPE = require('../../tokenizer').TYPE;
var NUMBER = TYPE.Number; var DELIM = TYPE.Delim; var SOLIDUS = 0x002F; // U+002F SOLIDUS (/)
var FULLSTOP = 0x002E; // U+002E FULL STOP (.)
// Terms of <ratio> should be a positive numbers (not zero or negative)
// (see https://drafts.csswg.org/mediaqueries-3/#values)
// However, -o-min-device-pixel-ratio takes fractional values as a ratio's term
// and this is using by various sites. Therefore we relax checking on parse
// to test a term is unsigned number without an exponent part.
// Additional checking may be applied on lexer validation.
function consumeNumber() { this.scanner.skipWS();
var value = this.consume(NUMBER);
for (var i = 0; i < value.length; i++) { var code = value.charCodeAt(i); if (!isDigit(code) && code !== FULLSTOP) { this.error('Unsigned number is expected', this.scanner.tokenStart - value.length + i); } }
if (Number(value) === 0) { this.error('Zero number is not allowed', this.scanner.tokenStart - value.length); }
return value; }
// <positive-integer> S* '/' S* <positive-integer>
module.exports = { name: 'Ratio', structure: { left: String, right: String }, parse: function() { var start = this.scanner.tokenStart; var left = consumeNumber.call(this); var right;
this.scanner.skipWS();
if (!this.scanner.isDelim(SOLIDUS)) { this.error('Solidus is expected'); } this.eat(DELIM); right = consumeNumber.call(this);
return { type: 'Ratio', loc: this.getLocation(start, this.scanner.tokenStart), left: left, right: right }; }, generate: function(node) { this.chunk(node.left); this.chunk('/'); this.chunk(node.right); } };
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