Fix types

lib/array.d.ts

@@ -0,0 +1,8 @@
+/**
+ * Flatten array, one level deep.
+ *
+ * @param arr
+ *
+ * @return
+ */
+export function flatten<T extends any[]>(arr: T[]): T;

lib/array.js

@@ -2,9 +2,11 @@
 /**
  * Flatten array, one level deep.
  *
- * @param {Array<?>} arr
+ * @template T
  *
- * @return {Array<?>}
+ * @param {T[][]} arr
+ *
+ * @return {T[]}
  */
 export function flatten(arr) {
   return Array.prototype.concat.apply([], arr);

lib/collection.d.ts

@@ -0,0 +1,174 @@
+
+export type Matcher<T> =
+  ((e: T) => boolean) |
+  ((e: T, idx: number) => boolean) |
+  ((e: T, key: string) => boolean) |
+  any;
+
+export type Extractor<T, U=T[keyof T]> = ((e: T) => U) | string | number;
+
+export type ArrayCollection<T> = Array<T>;
+export type StringKeyValueCollection<T> = { [key: string]: T };
+export type NumberKeyValueCollection<T> = { [key: number]: T };
+export type KeyValueCollection<T> = StringKeyValueCollection<T> | NumberKeyValueCollection<T>;
+export type Collection<T> = KeyValueCollection<T> | ArrayCollection<T>;
+
+/**
+ * Find element in collection.
+ *
+ * @param collection
+ * @param matcher
+ *
+ * @return
+ */
+export function find<T>(collection: Collection<T>, matcher: Matcher<T>): T | undefined;
+
+/**
+ * Find element index in collection.
+ *
+ * @param collection
+ * @param matcher
+ *
+ * @return
+ */
+export function findIndex<T>(collection: Collection<T>, matcher: Matcher<T>): number | undefined;
+
+/**
+ * Find element in collection.
+ *
+ * @param collection
+ * @param matcher
+ *
+ * @return result
+ */
+export function filter<T>(collection: Collection<T>, matcher: Matcher<T>): T[];
+
+/**
+ * Iterate over collection; returning something
+ * (non-undefined) will stop iteration.
+ *
+ * @param collection
+ * @param iterator
+ *
+ * @return return result that stopped the iteration
+ */
+export function forEach<T>(collection: Collection<T>, iterator: (item: T, convertKey: any /* TODO */) => boolean | void): T;
+
+/**
+ * Return collection without element.
+ *
+ * @param arr
+ * @param matcher
+ *
+ * @return
+ */
+export function without<T>(arr: T[], matcher: Matcher<T>): T[];
+
+/**
+ * Reduce collection, returning a single result.
+ *
+ * @param collection
+ * @param iterator
+ * @param result
+ *
+ * @return result returned from last iterator
+ */
+export function reduce<T, V>(collection: Collection<T>, iterator: (result: V, entry: T, index: any) => V, result: V): V;
+
+/**
+ * Return true if every element in the collection
+ * matches the criteria.
+ *
+ * @param collection
+ * @param matcher
+ *
+ * @return
+ */
+export function every<T>(collection: Collection<T>, matcher: Matcher<T>): boolean;
+
+/**
+ * Return true if some elements in the collection
+ * match the criteria.
+ *
+ * @param collection
+ * @param matcher
+ *
+ * @return
+ */
+export function some<T>(collection: Collection<T>, matcher: Matcher<T>): boolean;
+
+/**
+ * Transform a collection into another collection
+ * by piping each member through the given fn.
+ *
+ * @param collection
+ * @param fn
+ *
+ * @return transformed collection
+ */
+export function map<T, U>(collection: Collection<T>, fn: (value: T, key: number) => U): U[];
+
+/**
+ * Get the collections keys.
+ *
+ * @param collection
+ *
+ * @return
+ */
+export function keys<T>(collection: Collection<T>): T extends Array<any> ? number[] : (keyof T)[];
+
+/**
+ * Shorthand for `keys(o).length`.
+ *
+ * @param collection
+ *
+ * @return
+ */
+export function size<T>(collection: Collection<T>): number;
+
+/**
+ * Get the values in the collection.
+ *
+ * @param collection
+ *
+ * @return
+ */
+export function values<T>(collection: Collection<T>): T[];
+
+/**
+ * Group collection members by attribute.
+ *
+ * @param collection
+ * @param extractor
+ *
+ * @return map with { attrValue => [ a, b, c ] }
+ */
+export function groupBy<T>(collection: Collection<T>, extractor: Extractor<T>, grouped?: any): { [attrValue: string]: any[] };
+
+export function uniqueBy<T>(extractor: Extractor<T>, ...collections: Collection<T>[]): T[];
+export function unionBy<T>(extractor: Extractor<T>, ...collections: Collection<T>[]): T[];
+
+/**
+ * Sort collection by criteria.
+ *
+ * @param collection
+ * @param extractor
+ *
+ * @return
+ */
+export function sortBy<T>(collection: Collection<T>, extractor: Extractor<T, number | string>): T[];
+
+/**
+ * Create an object pattern matcher.
+ *
+ * @example
+ *
+ * const matcher = matchPattern({ id: 1 });
+ *
+ * let element = find(elements, matcher);
+ *
+ * @param pattern
+ *
+ * @return matcherFn
+ */
+export function matchPattern<T>(pattern: T): (e: any) => boolean;