68 lines
1.8 KiB
JavaScript
68 lines
1.8 KiB
JavaScript
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'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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