128 lines
3.5 KiB
JavaScript
128 lines
3.5 KiB
JavaScript
'use strict';
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const types = require('../../tokenizer/types.cjs');
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const MediaFeatureToken = new Set([types.Colon, types.RightParenthesis, types.EOF]);
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const SupportsFeatureToken = new Set([types.Colon, types.EOF]);
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const name = 'Condition';
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const structure = {
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kind: String,
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children: [[
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'Identifier',
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'Feature',
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'FeatureRange'
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]]
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};
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const conditions = {
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media() {
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if (this.tokenType === types.LeftParenthesis) {
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const firstToken = this.lookupTypeNonSC(1);
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if (firstToken === types.Ident && MediaFeatureToken.has(this.lookupTypeNonSC(2))) {
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return this.Feature('media');
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} else if (firstToken !== types.LeftParenthesis) {
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return this.parseWithFallback(() => this.FeatureRange('media'), (startIndex) => {
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this.skip(startIndex - this.tokenIndex);
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});
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}
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}
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},
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supports() {
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if (this.tokenType === types.LeftParenthesis) {
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if (this.lookupTypeNonSC(1) === types.Ident && SupportsFeatureToken.has(this.lookupTypeNonSC(2))) {
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return this.Declaration();
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}
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}
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},
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container() {
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if (this.tokenType === types.LeftParenthesis) {
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if (this.lookupTypeNonSC(1) === types.Ident && MediaFeatureToken.has(this.lookupTypeNonSC(2))) {
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return this.Feature('size');
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} else if (this.lookupTypeNonSC(1) !== types.LeftParenthesis) {
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return this.FeatureRange('size');
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}
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}
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}
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};
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function parse(kind = 'media') {
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const children = this.createList();
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const termParser = conditions[kind];
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scan: while (!this.eof) {
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switch (this.tokenType) {
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case types.Comment:
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case types.WhiteSpace:
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this.next();
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continue;
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case types.Ident:
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children.push(this.Identifier());
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break;
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case types.LeftParenthesis: {
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let term = termParser.call(this);
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if (!term) {
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term = this.parseWithFallback(() => {
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this.next();
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const res = this.Condition(kind);
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this.eat(types.RightParenthesis);
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return res;
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}, (startIndex) => {
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this.skip(startIndex - this.tokenIndex);
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return this.GeneralEnclosed();
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});
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}
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children.push(term);
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break;
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}
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case types.Function: {
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let term = termParser.call(this);
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if (!term) {
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term = this.GeneralEnclosed();
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}
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children.push(term);
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break;
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}
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default:
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break scan;
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}
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}
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if (children.isEmpty) {
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this.error('Condition can\'t be empty');
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}
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return {
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type: 'Condition',
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loc: this.getLocationFromList(children),
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kind,
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children
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};
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}
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function generate(node) {
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node.children.forEach(child => {
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if (child.type === 'Condition') {
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this.token(types.LeftParenthesis, '(');
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this.node(child);
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this.token(types.RightParenthesis, ')');
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} else {
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this.node(child);
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}
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});
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}
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exports.conditions = conditions;
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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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