113 lines
2.7 KiB
JavaScript
113 lines
2.7 KiB
JavaScript
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'use strict';
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const types = require('../../../tokenizer/types.cjs');
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const LESSTHANSIGN = 60; // <
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const EQUALSIGN = 61; // =
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const GREATERTHANSIGN = 62; // >
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const structure = {
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left: ['Identifier', 'Number', 'Dimension', 'Ratio'],
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leftComparison: String,
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middle: ['Identifier', 'Number', 'Dimension', 'Ratio'],
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rightComparison: [String, null],
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right: ['Identifier', 'Number', 'Dimension', 'Ratio', null]
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};
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function readTerm() {
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this.skipSC();
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switch (this.tokenType) {
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case types.Number:
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if (this.lookupNonWSType(1) === types.Delim) {
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return this.Ratio();
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} else {
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return this.Number();
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}
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case types.Dimension:
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return this.Dimension();
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case types.Ident:
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return this.Identifier();
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default:
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this.error('Number, dimension, ratio or identifier is expected');
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}
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}
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function readComparison(expectColon) {
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this.skipSC();
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if (this.isDelim(LESSTHANSIGN) ||
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this.isDelim(GREATERTHANSIGN)) {
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const value = this.source[this.tokenStart];
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this.next();
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if (this.isDelim(EQUALSIGN)) {
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this.next();
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return value + '=';
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}
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return value;
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}
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if (this.isDelim(EQUALSIGN)) {
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return '=';
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}
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this.error(`Expected ${expectColon ? '":", ' : ''}"<", ">", "=" or ")"`);
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}
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function createParse(type) {
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return function parse() {
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const start = this.tokenStart;
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this.skipSC();
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this.eat(types.LeftParenthesis);
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const left = readTerm.call(this);
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const leftComparison = readComparison.call(this, left.type === 'Identifier');
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const middle = readTerm.call(this);
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let rightComparison = null;
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let right = null;
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if (this.lookupNonWSType(0) !== types.RightParenthesis) {
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rightComparison = readComparison.call(this);
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right = readTerm.call(this);
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}
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this.skipSC();
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this.eat(types.RightParenthesis);
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return {
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type,
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loc: this.getLocation(start, this.tokenStart),
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left,
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leftComparison,
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middle,
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rightComparison,
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right
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};
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};
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}
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function generate(node) {
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this.token(types.LeftParenthesis, '(');
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this.node(node.left);
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this.tokenize(node.leftComparison);
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this.node(node.middle);
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if (node.right) {
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this.tokenize(node.rightComparison);
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this.node(node.right);
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}
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this.token(types.RightParenthesis, ')');
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}
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exports.createParse = createParse;
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exports.generate = generate;
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exports.structure = structure;
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