@rpearce/ts-fns

Public domain (LICENSE) Typescript helper functions for copying & pasting into projects. You can try it out here: https://npm.runkit.com/%40rpearce%2Fts-fns.

Most functions export two calling styles, regular and partial application:

// Regular
hasProp('color', { color: 'blue' }) // true

// Partial application
hasPropU('color')({ color: 'blue' }) // true

Special thanks to the following for helping with some typings!

Typed functions

Note: many functions have a unary, partial application style counterpart ending in U; e.g., cond also exports condU.

TODO

both
either
ifElse
neither
sortAscBy
sortDescBy
??? Open an issue to request something!

Usage

Copy the functions and types you need into your project.

Example

import {
  doesPropEq,
  doesPropEqU,
  takeN,
  takeNU,
} from './wherever-i-copied-the-helpers-to'

takeN(3, [1, 2, 3, 4])  // [1, 2, 3]
takeNU(3)([1, 2, 3, 4]) // [1, 2, 3]

doesPropEq('color', 'blue', { a: 'foo', b: 'bar', color: 'blue' })  // true
doesPropEqU('color')('blue')({ a: 'foo', b: 'bar', color: 'blue' }) // true

More in-depth unary partial application example

import { lift2U, propOrU } from './wherever-i-copied-the-helpers-to'

const propOrNA      = propOr('N/A')
const getName       = propOrNA('name')
const getEmail      = propOrNA('email')
const joinWithPipe  = (x: string) => (y: string) => `${x} | ${y}`
const joinNameEmail = lift2U(joinWithPipe)(getName)(getEmail)
const input         = { name: 'bobert', email: 'bobert@email.com', foo: 'bar' }

console.log(joinNameEmail(input))
// 'bobert | bobert@email.com'