stdlib.md

Standard Library

Add-on conveniences to make writing Vanilla JavaScript more expressive.

Usage: import { ... } from 'vpweb/stdlib';

function iter(list, f)

Iterator of anything indexable with a length. Skips undefined items.

Parameters:

• list — * — What to iterate over
• f(item,i) — function(*,number):void — Operation to perform

const iter_f

Create an iterator which will skip undefined items.

Parameters:

• f(item,i) — function(*,number):void — Operation to perform

Returns: function(*):void — Function which will iterate over its argument

const iter_obj

Iterate over all keys of an object. Does not filter.

Parameters:

• obj — Object — What to iterate over
• f(key,value) — function(string,*):void — Operation to perform on each key

function map(list, f)

Filtering mapper of anything indexable with a length, skipping undefined items and undefined callback results.

Parameters:

• list — * — What to iterate over
• f(item,i) — function(*,number):* — Map an item into another value

Returns: Array — All non-undefined results of f()

const map_obj

Map an object by key to an array.

Parameters:

• obj — Object — What to iterate over
• f(key,value) — function(string,*):* — Map a key to another value

Returns: Array — All results of f()

function fold(list, acc, f)

Fold anything indexable with a length.

Parameters:

• list — * — What to iterate over
• acc — * — Initial value for your accumulator
• f(acc,item,i) — function(*,*,number):* — Update accumulator with new value

const shift

Shift operation for Array-like objects

Alias of Array.prototype.shift()

const shifter

Create a function which will shift this array-like thing

Parameters:

• list — Object — Anything

Returns: function():* — Function which will shift list at each call

const cmp

Compare two scalars, returning 1, 0 or -1 depending on whether A is greater than, equal to or less than B.

Parameters:

• a — string|number
• b — string|number

Returns: number — Result

function cmp_bool(f, a, b)

Compare two things with a callback, returning 1, 0 or -1 depending on whether f(a), both or f(b) are true.

Parameters:

• f — function(*):boolean — Evaluator

function isPlainObject(o)

Tests whether something is a plain object (a.k.a. "object literal").

Parameters:

• o — * — Anything

Returns: boolean — Result