fp-pipe-ref

name	fp-pipe-ref
description	ALWAYS use this when the user mentions FP Pipe REF, asks to build, debug, review, document, automate, test, configure, migrate, or make decisions in this domain, or the task clearly depends on FP Pipe REF; scope: Quick reference for pipe and flow. Apply the bundled workflow, references, scripts, Senior Master standard, and Codex strict review gate before final output.

pipe & flow Quick Reference

Selective Reading Rule

Start with:

• references/senior-master-standard.md
• references/usage-routing.md
• references/quality-checklist.md

Then load only the inherited docs, scripts, assets, or examples that match the user's actual task.

pipe - Transform a Value

import { pipe } from 'fp-ts/function'

// pipe(startValue, fn1, fn2, fn3)
// = fn3(fn2(fn1(startValue)))

const result = pipe(
  '  hello world  ',
  s => s.trim(),
  s => s.toUpperCase(),
  s => s.split(' ')
)
// ['HELLO', 'WORLD']

flow - Create Reusable Pipeline

import { flow } from 'fp-ts/function'

// flow(fn1, fn2, fn3) returns a new function
const process = flow(
  (s: string) => s.trim(),
  s => s.toUpperCase(),
  s => s.split(' ')
)

process('  hello world  ') // ['HELLO', 'WORLD']
process('  foo bar  ')     // ['FOO', 'BAR']

When to Use

Use	When
pipe	Transform a specific value now
flow	Create reusable transformation

With fp-ts Types

import * as O from 'fp-ts/Option'
import * as A from 'fp-ts/Array'

// Option chain
pipe(
  O.fromNullable(user),
  O.map(u => u.email),
  O.getOrElse(() => 'no email')
)

// Array chain
pipe(
  users,
  A.filter(u => u.active),
  A.map(u => u.name)
)

Common Pattern

// Data last enables partial application
const getActiveNames = flow(
  A.filter((u: User) => u.active),
  A.map(u => u.name)
)

// Reuse anywhere
getActiveNames(users1)
getActiveNames(users2)

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.