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/**
* 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 = [];
}
}
/**
* Typescript doesn't allow friend access to private fields, so this just casts the set into a type
* with public access modifiers.
*/
function cast(set) {
return set;
}
/**
* Gets the index associated with `key` in the backing array, if it is already present.
*/
function get(setarr, key) {
return cast(setarr)._indexes[key];
}
/**
* Puts `key` into the backing array, if it is not already present. Returns
* the index of the `key` in the backing array.
*/
function put(setarr, key) {
// The key may or may not be present. If it is present, it's a number.
const index = get(setarr, key);
if (index !== undefined)
return index;
const { array, _indexes: indexes } = cast(setarr);
const length = array.push(key);
return (indexes[key] = length - 1);
}
/**
* Pops the last added item out of the SetArray.
*/
function pop(setarr) {
const { array, _indexes: indexes } = cast(setarr);
if (array.length === 0)
return;
const last = array.pop();
indexes[last] = undefined;
}
/**
* Removes the key, if it exists in the set.
*/
function remove(setarr, key) {
const index = get(setarr, key);
if (index === undefined)
return;
const { array, _indexes: indexes } = cast(setarr);
for (let i = index + 1; i < array.length; i++) {
const k = array[i];
array[i - 1] = k;
indexes[k]--;
}
indexes[key] = undefined;
array.pop();
}
export { SetArray, get, pop, put, remove };
//# sourceMappingURL=set-array.mjs.map
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