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