@adobe/helix-pipeline
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This project provides helper functions and default implementations for creating Hypermedia Processing Pipelines.
43 lines (40 loc) • 1.61 kB
JavaScript
/*
* Copyright 2018 Adobe. All rights reserved.
* This file is licensed to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License. You may obtain a copy
* of the License at http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under
* the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
* OF ANY KIND, either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
/**
* Turns a content-expression like "heading? (paragraph|image)+" into
* a proper regular expression.
* @param {string} pattern the content expression
* @returns {RegExp} a regular expression that matches strings following
* the high-level pattern.
*/
export function compile(pattern) {
const expression = new RegExp(pattern
.replace(/(\w+)/g, '($1·)') // always match whole words
.replace(/ /g, '') // remove spaces
.toString());
// console.log('=> ' + expression);
return expression;
}
/**
* Determines if the provided list of child nodes matches the
* type expression
* @param {string[]} list a list of node types
* @param {string} pattern a content-expression like "heading? (paragraph|image)+"
* @returns true if the list matches the pattern
*/
export function match(list, pattern) {
const str = `${list.join('·')}·`;
// console.log('-> ' + str);
const matches = !!compile(pattern).test(str);
// console.log(matches);
return matches;
}