| 'use strict'; |
| |
| const types = require('../../tokenizer/types.cjs'); |
| const charCodeDefinitions = require('../../tokenizer/char-code-definitions.cjs'); |
| |
| const SOLIDUS = 0x002F; // U+002F SOLIDUS (/) |
| const 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.skipSC(); |
| |
| const value = this.consume(types.Number); |
| |
| for (let i = 0; i < value.length; i++) { |
| const code = value.charCodeAt(i); |
| if (!charCodeDefinitions.isDigit(code) && code !== FULLSTOP) { |
| this.error('Unsigned number is expected', this.tokenStart - value.length + i); |
| } |
| } |
| |
| if (Number(value) === 0) { |
| this.error('Zero number is not allowed', this.tokenStart - value.length); |
| } |
| |
| return value; |
| } |
| |
| const name = 'Ratio'; |
| const structure = { |
| left: String, |
| right: String |
| }; |
| |
| // <positive-integer> S* '/' S* <positive-integer> |
| function parse() { |
| const start = this.tokenStart; |
| const left = consumeNumber.call(this); |
| let right; |
| |
| this.skipSC(); |
| this.eatDelim(SOLIDUS); |
| right = consumeNumber.call(this); |
| |
| return { |
| type: 'Ratio', |
| loc: this.getLocation(start, this.tokenStart), |
| left, |
| right |
| }; |
| } |
| |
| function generate(node) { |
| this.token(types.Number, node.left); |
| this.token(types.Delim, '/'); |
| this.token(types.Number, node.right); |
| } |
| |
| exports.generate = generate; |
| exports.name = name; |
| exports.parse = parse; |
| exports.structure = structure; |