[d565449] | 1 | /**
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| 2 | * SetArray acts like a `Set` (allowing only one occurrence of a string `key`), but provides the
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| 3 | * index of the `key` in the backing array.
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| 4 | *
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| 5 | * This is designed to allow synchronizing a second array with the contents of the backing array,
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| 6 | * like how in a sourcemap `sourcesContent[i]` is the source content associated with `source[i]`,
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| 7 | * and there are never duplicates.
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| 8 | */
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| 9 | class SetArray {
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| 10 | constructor() {
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| 11 | this._indexes = { __proto__: null };
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| 12 | this.array = [];
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| 13 | }
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| 14 | }
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| 15 | /**
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| 16 | * Typescript doesn't allow friend access to private fields, so this just casts the set into a type
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| 17 | * with public access modifiers.
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| 18 | */
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| 19 | function cast(set) {
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| 20 | return set;
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| 21 | }
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| 22 | /**
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| 23 | * Gets the index associated with `key` in the backing array, if it is already present.
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| 24 | */
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| 25 | function get(setarr, key) {
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| 26 | return cast(setarr)._indexes[key];
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| 27 | }
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| 28 | /**
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| 29 | * Puts `key` into the backing array, if it is not already present. Returns
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| 30 | * the index of the `key` in the backing array.
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| 31 | */
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| 32 | function put(setarr, key) {
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| 33 | // The key may or may not be present. If it is present, it's a number.
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| 34 | const index = get(setarr, key);
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| 35 | if (index !== undefined)
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| 36 | return index;
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| 37 | const { array, _indexes: indexes } = cast(setarr);
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| 38 | const length = array.push(key);
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| 39 | return (indexes[key] = length - 1);
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| 40 | }
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| 41 | /**
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| 42 | * Pops the last added item out of the SetArray.
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| 43 | */
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| 44 | function pop(setarr) {
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| 45 | const { array, _indexes: indexes } = cast(setarr);
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| 46 | if (array.length === 0)
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| 47 | return;
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| 48 | const last = array.pop();
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| 49 | indexes[last] = undefined;
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| 50 | }
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| 51 | /**
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| 52 | * Removes the key, if it exists in the set.
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| 53 | */
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| 54 | function remove(setarr, key) {
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| 55 | const index = get(setarr, key);
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| 56 | if (index === undefined)
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| 57 | return;
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| 58 | const { array, _indexes: indexes } = cast(setarr);
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| 59 | for (let i = index + 1; i < array.length; i++) {
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| 60 | const k = array[i];
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| 61 | array[i - 1] = k;
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| 62 | indexes[k]--;
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| 63 | }
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| 64 | indexes[key] = undefined;
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| 65 | array.pop();
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| 66 | }
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| 67 |
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| 68 | export { SetArray, get, pop, put, remove };
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| 69 | //# sourceMappingURL=set-array.mjs.map
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