@stopcock/fp

Pipe-based functional programming for TypeScript. Fuses array operations into single loops.

bun add @stopcock/fp

import { pipe, flow, A, S, N, O, R } from '@stopcock/fp'

const leaderboard = pipe(
  users,
  A.filter(u => u.active && u.score > 0),
  A.sortBy((a, b) => b.score - a.score),
  A.take(10),
  A.map(u => u.name),
)

filter → map fuses into a single loop. take(10) bails out early.

What's in the box

• pipe / flow — left-to-right composition, with automatic fusion for array chains
• A (Array), S (String), D (Dict), N (Number), M (Math), B (Boolean), Obj (Object), Logic — namespaced utilities, all pipe-friendly
• O (Option), R (Result) — sum types for nullable values and fallible operations, numeric tags for fast branching
• G (Guards) — type narrowing: isString, isNil, isPlainObject, etc.
• Lenses — lens, lensProp, lensIndex, lensPath, view, set, over

Every function is dual: data-first or data-last.

A.take(users, 5)       // data-first
pipe(users, A.take(5)) // data-last

Docs