Files F95206522

set-array.mjs
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Created: Fri, Dec 13, 17:50

set-array.mjs
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	/**
	* Gets the index associated with `key` in the backing array, if it is already present.
	*/
	let get;
	/**
	* Puts `key` into the backing array, if it is not already present. Returns
	* the index of the `key` in the backing array.
	*/
	let put;
	/**
	* Pops the last added item out of the SetArray.
	*/
	let pop;
	/**
	* SetArray acts like a `Set` (allowing only one occurrence of a string `key`), but provides the
	* index of the `key` in the backing array.
	*
	* This is designed to allow synchronizing a second array with the contents of the backing array,
	* like how in a sourcemap `sourcesContent[i]` is the source content associated with `source[i]`,
	* and there are never duplicates.
	*/
	class SetArray {
	constructor() {
	this._indexes = { __proto__: null };
	this.array = [];
	}
	}
	(() => {
	get = (strarr, key) => strarr._indexes[key];
	put = (strarr, key) => {
	// The key may or may not be present. If it is present, it's a number.
	const index = get(strarr, key);
	if (index !== undefined)
	return index;
	const { array, _indexes: indexes } = strarr;
	return (indexes[key] = array.push(key) - 1);
	};
	pop = (strarr) => {
	const { array, _indexes: indexes } = strarr;
	if (array.length === 0)
	return;
	const last = array.pop();
	indexes[last] = undefined;
	};
	})();

	export { SetArray, get, pop, put };
	//# sourceMappingURL=set-array.mjs.map

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