@formatjs/ecma402-abstract/PartitionPattern.js

A collection of implementation for ECMAScript abstract operations

import { invariant } from "./utils.js";
/**
* Partition a pattern into a list of literals and placeholders
* https://tc39.es/ecma402/#sec-partitionpattern
* @param pattern
*/
export function PartitionPattern(pattern) {
	const result = [];
	let beginIndex = pattern.indexOf("{");
	let endIndex = 0;
	let nextIndex = 0;
	const length = pattern.length;
	while (beginIndex < pattern.length && beginIndex > -1) {
		endIndex = pattern.indexOf("}", beginIndex);
		invariant(endIndex > beginIndex, `Invalid pattern ${pattern}`);
		if (beginIndex > nextIndex) {
			result.push({
				type: "literal",
				value: pattern.substring(nextIndex, beginIndex)
			});
		}
		result.push({
			type: pattern.substring(beginIndex + 1, endIndex),
			value: undefined
		});
		nextIndex = endIndex + 1;
		beginIndex = pattern.indexOf("{", nextIndex);
	}
	if (nextIndex < length) {
		result.push({
			type: "literal",
			value: pattern.substring(nextIndex, length)
		});
	}
	return result;
}