| var isNumber = require('../../tokenizer').isNumber; |
| var TYPE = require('../../tokenizer').TYPE; |
| var NUMBER = TYPE.Number; |
| var SOLIDUS = TYPE.Solidus; |
| var FULLSTOP = TYPE.FullStop; |
| |
| // Terms of <ratio> should to be a positive number (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 exponent part. |
| // Additional checks may to be applied on lexer validation. |
| function consumeNumber(scanner) { |
| var value = scanner.consumeNonWS(NUMBER); |
| |
| for (var i = 0; i < value.length; i++) { |
| var code = value.charCodeAt(i); |
| if (!isNumber(code) && code !== FULLSTOP) { |
| scanner.error('Unsigned number is expected', scanner.tokenStart - value.length + i); |
| } |
| } |
| |
| if (Number(value) === 0) { |
| scanner.error('Zero number is not allowed', 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(this.scanner); |
| var right; |
| |
| this.scanner.eatNonWS(SOLIDUS); |
| right = consumeNumber(this.scanner); |
| |
| 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); |
| } |
| }; |