fontoxpath/src/selectors/arrays/ArrayConstructor.js

A minimalistic XPath 3.1 engine in JavaScript

import Selector from '../Selector';
import Specificity from '../Specificity';
import ArrayValue from '../dataTypes/ArrayValue';
import Sequence from '../dataTypes/Sequence';

/**
 * @extends {Selector}
 */
class ArrayConstructor extends Selector {
	/**
	 * @param   {string}           curlyness  Whether this constructor should use curly behaviour
	 *                                         Curly behaviour unfolds the single entry sequence, square constructor does not unfold
	 * @param   {!Array<!Selector>}  members    The selectors for the values
	 */
	constructor (curlyness, members) {
		super(new Specificity({
				[Specificity.EXTERNAL_KIND]: 1
		}), {
			canBeStaticallyEvaluated: members.every(member => member.canBeStaticallyEvaluated)
		});
		this._curlyness = curlyness;
		this._members = members;
	}


	evaluate (dynamicContext) {
		if (this._curlyness === 'curly') {
			return this._members[0].evaluateMaybeStatically(dynamicContext)
				.mapAll(allValues => Sequence.singleton(new ArrayValue(allValues.map(Sequence.singleton))));
		}

		return Sequence.singleton(
			new ArrayValue(this._members.map(entry => entry.evaluateMaybeStatically(dynamicContext))));
	}
}
export default ArrayConstructor;