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