Functional

Functional is just a library for Functional Programming in TypeScript with optimal tree-shaking support.

Installation

npm install @keienla/functional

Usage

This library is designed with optimal tree-shaking in mind. You can import functions in two ways:

Tree-Shaking Optimized (Recommended)

Import only the functions you need for the smallest possible bundle size:

// Individual imports (best for tree-shaking)
import curry from '@keienla/functional/curry';
import add from '@keienla/functional/add';
import pipe from '@keienla/functional/pipe';

// Usage
const addCurried = curry(add);
const result = pipe(
  addCurried(1),
  addCurried(2)
)(5); // 8

Barrel Import

Import multiple functions from the main entry point:

// Multiple imports from main entry
import { curry, add, pipe, map, filter } from '@keienla/functional';

// Usage
const numbers = [1, 2, 3, 4, 5];
const result = pipe(
  filter((x: number) => x > 2),
  map(add(10))
)(numbers); // [13, 14, 15]

Available Import Paths

For optimal tree-shaking, you can import any function directly:

// Direct function imports
import curry from '@keienla/functional/curry';
import compose from '@keienla/functional/compose';
import map from '@keienla/functional/map';
import filter from '@keienla/functional/filter';
import { _ } from '@keienla/functional/blank';

// Type utilities
import { isString, isNumber } from '@keienla/functional/isType';

Tree-Shaking Benefits

This library is configured with:

• ✅ ESM modules for optimal bundler support
• ✅ "sideEffects": false to ensure safe tree-shaking
• ✅ Individual exports for direct function imports
• ✅ TypeScript declarations with proper type inference

When using individual imports, bundlers like Webpack, Rollup, and Vite will only include the functions you actually use, resulting in significantly smaller bundle sizes.

Methods

• add
• and
• arity
• arrayIs
• compose
• constant
• curry
• deepFreeze
• divide
• filter
• filterObject
• flipArgs
• freeze
• gatherArgs
• identity
• is
• isLength
• isnt
• isType
• length
• map
• mapObject
• memoize
• multiply
• nAry
• not
• notSameLength
• objectIs
• or
• partial
• pick
• pickAll
• pipe
• reduce
• reduceObject
• reverseArgs
• sameLength
• spreadArgs
• substract
• transpoline
• type
• unAry
• uncurry
• when
• whenElse

Maybe todo one day

• [ ] Monades
• [ ] Map/Filter function with Transducers?

Build

After npm run build, if want to create a pack folder, go to the dist folder and run "npm pack" -->