sequence-js/src/equality-map/impl.ts

import { asAsyncEqualityComparer } from "../equality-comparer/async.js";
import { asEqualityComparer } from "../equality-comparer/sync.js";
import { AsyncEqualityComparer, EqualityComparer, EqualityComparisonOrComparer, MaybeAsyncEqualityComparisonOrComparer } from "../equality-comparer/types.js";
import { MaybeAsyncIterable } from "../types.js";
import { AsyncEqualityMap, EqualityMap, EqualityMapEntry } from "./types.js";

export class NativeEqualityMap<K, V> implements EqualityMap<K, V> {
  readonly #map = new Map<K, V>();

  get size() {
    return this.#map.size;
  }

  get(key: K) {
    return this.#map.get(key);
  }

  set(key: K, value: V) {
    const existing = this.get(key);
    this.#map.set(key, value);
    return existing;
  }

  setAll(entries: Iterable<EqualityMapEntry<K, V>>) {
    for (const [key, value] of entries) {
      this.set(key, value);
    }
  }

  contains(key: K) {
    return this.#map.has(key);
  }

  remove(key: K) {
    const existing = this.get(key);
    this.#map.delete(key);
    return existing;
  }

  clear() {
    this.#map.clear();
  }

  keys() {
    return this.#map.keys();
  }

  values() {
    return this.#map.values();
  }

  entries() {
    return this.#map.entries();
  }

  [Symbol.iterator]() {
    return this.#map[Symbol.iterator]();
  }
}

export class CustomEqualityMap<K, V> implements EqualityMap<K, V> {
  readonly #list: EqualityMapEntry<K, V>[] = [];
  readonly #keyComparer: EqualityComparer<K>;

  constructor(keyComparer: EqualityComparisonOrComparer<K>) {
    this.#keyComparer = asEqualityComparer(keyComparer);
  }

  get size() {
    return this.#list.length;
  }

  get(key: K) {
    for (const entry of this.#list) {
      if (this.#keyComparer.equals(key, entry[0])) {
        return entry[1];
      }
    }

    return undefined;
  }

  set(key: K, value: V) {
    for (const entry of this.#list) {
      if (this.#keyComparer.equals(key, entry[0])) {
        const previous = entry[1];
        entry[1] = value;
        return previous;
      }
    }

    this.#list.push([key, value]);

    return undefined;
  }

  setAll(entries: Iterable<EqualityMapEntry<K, V>>) {
    for (const [key, value] of entries) {
      this.set(key, value);
    }
  }

  contains(key: K) {
    for (const entry of this.#list) {
      if (this.#keyComparer.equals(key, entry[0])) {
        return true;
      }
    }

    return false;
  }

  remove(key: K) {
    for (let i = 0; i < this.#list.length; i++) {
      if (this.#keyComparer.equals(key, this.#list[i][0])) {
        const removed = this.#list.splice(i, 1);
        return removed[0][1];
      }
    }

    return undefined;
  }

  clear() {
    this.#list.length = 0;
  }

  *keys() {
    for (const entry of this.#list) {
      yield entry[0];
    }
  }

  *values() {
    for (const entry of this.#list) {
      yield entry[1];
    }
  }

  entries() {
    return this[Symbol.iterator]();
  }

  *[Symbol.iterator]() {
    for (const entry of this.#list) {
      yield entry.slice() as EqualityMapEntry<K, V>; // no entry mutation allowed!
    }
  }
}

export class NativeAsyncEqualityMap<K, V> implements AsyncEqualityMap<K, V> {
  readonly #map = new Map<K, V>();

  get size() {
    return this.#map.size;
  }

  async get(key: K) {
    return this.#map.get(key);
  }

  async set(key: K, value: V) {
    const existing = await this.get(key);
    this.#map.set(key, value);
    return existing;
  }

  async setAll(entries: MaybeAsyncIterable<EqualityMapEntry<K, V>>) {
    for await (const [key, value] of entries) {
      await this.set(key, value);
    }
  }

  async contains(key: K) {
    return this.#map.has(key);
  }

  async remove(key: K) {
    const existing = await this.get(key);
    this.#map.delete(key);
    return existing;
  }

  clear() {
    this.#map.clear();
  }

  keys() {
    return this.#map.keys();
  }

  values() {
    return this.#map.values();
  }

  entries() {
    return this.#map.entries();
  }

  [Symbol.iterator]() {
    return this.#map[Symbol.iterator]();
  }
}

export class CustomAsyncEqualityMap<K, V> implements AsyncEqualityMap<K, V> {
  readonly #list: EqualityMapEntry<K, V>[] = [];
  readonly #keyComparer: AsyncEqualityComparer<K>;

  constructor(keyComparer: MaybeAsyncEqualityComparisonOrComparer<K>) {
    this.#keyComparer = asAsyncEqualityComparer(keyComparer);
  }

  get size() {
    return this.#list.length;
  }

  async get(key: K) {
    for (const entry of this.#list) {
      if (await this.#keyComparer.equals(key, entry[0])) {
        return entry[1];
      }
    }

    return undefined;
  }

  async set(key: K, value: V) {
    for (const entry of this.#list) {
      if (await this.#keyComparer.equals(key, entry[0])) {
        const previous = entry[1];
        entry[1] = value;
        return previous;
      }
    }

    this.#list.push([key, value]);

    return undefined;
  }

  async setAll(entries: MaybeAsyncIterable<EqualityMapEntry<K, V>>) {
    for await (const [key, value] of entries) {
      await this.set(key, value);
    }
  }

  async contains(key: K) {
    for (const entry of this.#list) {
      if (await this.#keyComparer.equals(key, entry[0])) {
        return true;
      }
    }

    return false;
  }

  async remove(key: K) {
    for (let i = 0; i < this.#list.length; i++) {
      if (await this.#keyComparer.equals(key, this.#list[i][0])) {
        const removed = this.#list.splice(i, 1);
        return removed[0][1];
      }
    }

    return undefined;
  }

  clear() {
    this.#list.length = 0;
  }

  *keys() {
    for (const entry of this.#list) {
      yield entry[0];
    }
  }

  *values() {
    for (const entry of this.#list) {
      yield entry[1];
    }
  }

  entries() {
    return this[Symbol.iterator]();
  }

  *[Symbol.iterator]() {
    for (const entry of this.#list) {
      yield entry.slice() as EqualityMapEntry<K, V>; // no entry mutation allowed!
    }
  }
}