2019-08-31 20:51:14 -07:00

263 lines
10 KiB
TypeScript

import { identity, not } from 'wherehows-web/utils/helpers/functions';
/**
* Composable function that will in turn consume an item from a list an emit a result of equal or same type
* @type Iteratee
*/
export type Iteratee<A, R> = (a: A) => R;
/**
* Aliases a type T or an array of type T
* @template T
* @alias
*/
export type Many<T> = T | Array<T>;
/**
* Takes a number of elements in the list from the start up to the length of the list
* @template T type of elements in array
* @param {number} [n=0] number of elements to take from the start of the array
*/
export const take = <T>(n: number = 0): ((list: Array<T>) => Array<T>) => (list: Array<T>): Array<T> =>
Array.prototype.slice.call(list, 0, n < 0 ? 0 : n);
/**
* Convenience utility takes a type-safe mapping function, and returns a list mapping function
* @template T
* @template U
* @param {(param: T, index: number, collection: Array<T>) => U} predicate maps a type T to type U
* @returns {((array: Array<T>) => Array<U>)}
*/
export const arrayMap = <T, U>(
predicate: (param: T, index: number, collection: Array<T>) => U
): ((array: Array<T>) => Array<U>) => (array = []) => array.map(predicate);
/**
* Iteratee-first data-last each function
* @template T type of elements in array
* @param {(param: T) => void} predicate iteratee
* @returns {((array: Array<T>) => void)}
*/
export const arrayEach = <T>(predicate: (param: T) => void): ((array: Array<T>) => void) => (array = []) =>
array.forEach(predicate);
/**
* Partitions an array into a tuple containing elements that meet the predicate in the zeroth index,
* and excluded elements in the next
* `iterate-first data-last` function
* @template T type of source element list
* @template U subtype of T in first partition
* @param {(param: T) => param is U} predicate is a type guard function
* @returns {((array: Array<T>) => [Array<U>, Array<Exclude<T, U>>])}
*/
export const arrayPartition = <T, U extends T>(
predicate: (param: T) => param is U
): ((array: Array<T>) => [Array<U>, Array<Exclude<T, U>>]) => (array = []) => [
array.filter(predicate),
array.filter<Exclude<T, U>>((v: T): v is Exclude<T, U> => not(predicate)(v))
];
/**
* Convenience utility takes a type-safe filter function, and returns a list filtering function
* @param {(param: T) => boolean} predicate
* @return {(array: Array<T>) => Array<T>}
*/
export const arrayFilter = <T>(predicate: (param: T) => boolean): ((array: Array<T>) => Array<T>) => (array = []) =>
array.filter(predicate);
/**
* Type safe utility `iterate-first data-last` function for array every
* @template T
* @param {(param: T) => boolean} predicate
* @returns {((array: Array<T>) => boolean)}
*/
export const arrayEvery = <T>(predicate: (param: T) => boolean): ((array: Array<T>) => boolean) => (array = []) =>
array.every(predicate);
/**
* Type safe utility `iterate-first data-last` function for array some
* @template T
* @param {(param: T) => boolean} predicate
* @return {(array: Array<T>) => boolean}
*/
export const arraySome = <T>(predicate: (param: T) => boolean): ((array: Array<T>) => boolean) => (array = []) =>
array.some(predicate);
/**
* Composable reducer abstraction, curries a reducing iteratee and returns a reducing function that takes a list
* @template U
* @param {(acc: U) => U} iteratee
* @param {U} init the initial value in the reduction sequence
* @return {(arr: Array<T>) => U}
*/
export const arrayReduce = <T, U>(
iteratee: (accumulator: U, element: T, index: number, collection: Array<T>) => U,
init: U
): ((arr: Array<T>) => U) => (array = []) => array.reduce(iteratee, init);
// arrayPipe overloads
export function arrayPipe<T, R1 = T>(f1: (a1: T) => R1): (x: T) => R1;
export function arrayPipe<T, R1 = T, R2 = T>(f1: (a1: T) => R1, f2: (a2: R1) => R2): (x: T) => R2;
export function arrayPipe<T, R1 = T, R2 = T, R3 = T>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3
): (x: T) => R3;
export function arrayPipe<T, R1 = T, R2 = T, R3 = T, R4 = T>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3,
f4: (a4: R3) => R4
): (x: T) => R4;
export function arrayPipe<T, R1 = T, R2 = T, R3 = T, R4 = T, R5 = T>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3,
f4: (a4: R3) => R4,
f5: (a5: R4) => R5
): (x: T) => R5;
export function arrayPipe<T, R1, R2, R3, R4, R5, R6>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3,
f4: (a4: R3) => R4,
f5: (a5: R4) => R5,
f6: (a6: R5) => R6
): (x: T) => R6;
export function arrayPipe<T, R1, R2, R3, R4, R5, R6, R7>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3,
f4: (a4: R3) => R4,
f5: (a5: R4) => R5,
f6: (a6: R5) => R6,
f7: (a7: R6) => R7
): (x: T) => R7;
/**
* overload to handle case of too many functions being piped, provides less type safety once args exceeds 7 iteratees
* @param {(a1: T) => R1} f1
* @param {(a2: R1) => R2} f2
* @param {(a3: R2) => R3} f3
* @param {(a4: R3) => R4} f4
* @param {(a5: R4) => R5} f5
* @param {(a6: R5) => R6} f6
* @param {(a7: R6) => R7} f7
* @param {Many<Iteratee<any, any>>} fns
* @return {(arg: T) => any}
*/
export function arrayPipe<T, R1, R2, R3, R4, R5, R6, R7>(
f1: (a1: T) => R1,
f2: (a2: R1) => R2,
f3: (a3: R2) => R3,
f4: (a4: R3) => R4,
f5: (a5: R4) => R5,
f6: (a6: R5) => R6,
f7: (a7: R6) => R7,
// eslint-disable-next-line @typescript-eslint/no-explicit-any
...fns: Array<Many<Iteratee<any, any>>>
): // eslint-disable-next-line @typescript-eslint/no-explicit-any
(arg: T) => any;
/**
* Takes a list (array / separate args) of iteratee functions, with each successive iteratee is
* invoked with the result of the previous iteratee invocation
* @template T the type of elements in the array
* @template R the result of executing the last iteratee
* @param {Many<Iteratee<any, any>>} fns
* @return {(x: T) => R}
*/
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export function arrayPipe<T, R>(...fns: Array<Many<Iteratee<any, any>>>): (x: T) => R {
// eslint-disable-next-line @typescript-eslint/no-explicit-any
return arrayReduce<(a: T) => any, (x: any) => R>((acc, f) => (x): R => acc(f(x)), identity)(
// eslint-disable-next-line @typescript-eslint/no-explicit-any
([] as Array<Iteratee<any, any>>).concat(...fns.reverse()) // flatten if arg is of type Array<>
);
}
/**
* Duplicate check using every to short-circuit iteration
* @template T
* @param {Array<T>} [list = []] list to check for dupes
* @return {boolean} true is unique
*/
export const isListUnique = <T>(list: Array<T> = []): boolean => new Set(list).size === list.length;
/**
* Extracts all non falsey values from a list.
* @template T
* @param {Array<T>} list the list of items to compact
* @return {Array<T>}
*/
export const compact = <T>(list: Array<T> = []): Array<T> => list.filter(item => item);
/**
* Defines the interface for options that may be passed into the chunk function
* @interface {IChunkArrayOptions}
*/
interface IChunkArrayOptions {
chunkSize?: 50 | 100;
context?: null | object;
}
/**
* Asynchronously traverses a list in small chunks ensuring that a list can be iterated over without
* blocking the browser main thread.
* @template T type of values in list to be iterated over
* @template U the type of the value that is produced by an iteration of the list
* @param {(arr?: Array<T>) => U} iterateeSync an iteratee that consumes an list and returns a value of type U
* @param {(res: U) => U} accumulator a function that combines the result of successive iterations of the original list
* @param {IChunkArrayOptions} [{chunkSize = 50, context = null}={chunkSize: 50, context: null}]
* @param {50 | 100} chunkSize the maximum size to chunk at a time
* @param {object | null} [context] the optional execution context for the iteratee invocation
* @return {(list: Array<T>) => Promise<U>}
*/
export const chunkArrayAsync = <T, U>(
iterateeSync: (arr?: Array<T>) => U,
accumulator: (res: U) => U,
{ chunkSize = 50, context = null }: IChunkArrayOptions = { chunkSize: 50, context: null }
): ((list: Array<T>) => Promise<U>) => (list: Array<T>) =>
new Promise<U>(function(resolve) {
const queue = list.slice(0); // creates a shallow copy of the original list
let result: U;
requestAnimationFrame(function chunk() {
const startTime = +new Date();
do {
result = accumulator(iterateeSync.call(context, queue.splice(0, chunkSize)));
} while (queue.length && +new Date() + startTime < 18);
// recurse through list if there are more items left
return queue.length ? requestAnimationFrame(chunk) : resolve(result);
});
});
/**
* Asynchronously traverse a list and accumulate another list based on the iteratee
* @template T the type of values in the original list
* @template U the type of values in the transformed list
* @param {(arr?: Array<T>) => Array<U>} iteratee consumes a list and returns a new list of values
* @return {(list: Array<T>, context?: any) => Promise<Array<U>>}
*/
export const iterateArrayAsync = <T, U = T>(
iteratee: (arr?: Array<T>) => Array<U>
): ((list: Array<T>, context?: null) => Promise<Array<U>>) => (list: Array<T>, context = null): Promise<Array<U>> => {
const accumulator = (base: Array<U>): ((arr: Array<U>) => Array<U>) => (arr: Array<U>) => (base = [...base, ...arr]);
return chunkArrayAsync(iteratee, accumulator([]), { chunkSize: 50, context })(list);
};
/**
* Asynchronously traverse a list and accumulate a value of type U, applies to cases of reduction or accumulation
* @template T the type of values in the original list
* @template U the type of value to be produced by reducing the list
* @param {(arr?: Array<T>) => U} reducer consumes a list and produces a single value
* @return {(list: Array<T>, context?: any) => Promise<U>}
*/
export const reduceArrayAsync = <T, U>(
reducer: (arr?: Array<T>) => U
): ((list: Array<T>, context?: null) => Promise<U>) => (list: Array<T>, context = null): Promise<U> => {
const accumulator = (base: U): ((int: U) => U) => (int: U) => Object.assign(base, int);
return chunkArrayAsync(reducer, accumulator(reducer.call(context)))(list);
};