FeatureRange.cjs•2.68 kB
'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;