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Pipeable

The Pipeable module defines the shared interface and implementation helpers for values that support Effect-style method chaining with .pipe(...).

A Pipeable value can pass itself through a sequence of unary functions from left to right, so code can be written as value.pipe(f, g, h) instead of deeply nesting calls. This is the method form used by many Effect data types to compose transformations, validations, and effectful operations while keeping the original value as the starting point of the pipeline.

6 exports Since v2.0.0 Source

Combinators

pipeArguments

Since v2.0.0

Applies a pipe method's variadic arguments to an initial value from left to right.

When to use

Use to implement a custom .pipe(...) method from JavaScript's arguments object.

Details

This helper is intended for implementing Pipeable.pipe methods that receive JavaScript's arguments object. With no functions it returns the original value; otherwise it feeds each result into the next function.

Signature

declare function pipeArguments<A>(self: A, args: IArguments): unknown

Example Implementing a pipe method 

import { Pipeable } from "effect"


class NumberBox {
  constructor(readonly value: number) {}


  pipe(..._fns: ReadonlyArray<(value: number) => number>): number {
    return Pipeable.pipeArguments(this.value, arguments) as number
  }
}


const result = new NumberBox(5).pipe(
  (n) => n + 2,
  (n) => n * 3
)
result // => 21

Constructors

Class

Since v3.15.0

Provides a base constructor whose instances implement the standard Pipeable.pipe method.

When to use

Use when you need to define a class that supports Effect-style method chaining through .pipe(...).

Signature

declare const Class: () => Pipeable

Mixin

Since v4.0.0

Returns a subclass of the provided class that adds the standard pipe method.

When to use

Use to add pipe support to an existing class without extending a base class or modifying its prototype.

Details

The original constructor and instance members are preserved, and the added method delegates to pipeArguments.

See

  • Prototype for a reusable prototype object
  • Class for a base constructor to extend

Signature

declare function Mixin<TBase extends (...args: readonly Array<any>) => any>(klass: TBase): TBase & PipeableConstructor

Models

Pipeable

interface
Since v2.0.0

Interface for values that support method-style pipe composition.

When to use

Use to type values that expose an Effect-style .pipe(...) method.

Details

Calling value.pipe(f, g, h) passes the value through each function from left to right, returning the final result. Many Effect data types implement this so operations can be chained without nesting function calls.

Signature

interface Pipeable {
  pipe<A>(this: A): A;
  pipe<A, B = never>(this: A, ab: (_: A) => B): B;
  pipe<A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C;
  pipe<A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D;
  pipe<A, B = never, C = never, D = never, E = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E): E;
  pipe<A, B = never, C = never, D = never, E = never, F = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F): F;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G): G;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H): H;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I): I;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J): J;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K): K;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L): L;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M): M;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N): N;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O): O;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P): P;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q): Q;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never, R = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q, qr: (_: Q) => R): R;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never, R = never, S = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q, qr: (_: Q) => R, rs: (_: R) => S): S;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never, R = never, S = never, T = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q, qr: (_: Q) => R, rs: (_: R) => S, st: (_: S) => T): T;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never, R = never, S = never, T = never, U = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q, qr: (_: Q) => R, rs: (_: R) => S, st: (_: S) => T, tu: (_: T) => U): U;
  pipe<A, B = never, C = never, D = never, E = never, F = never, G = never, H = never, I = never, J = never, K = never, L = never, M = never, N = never, O = never, P = never, Q = never, R = never, S = never, T = never, U = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D, de: (_: D) => E, ef: (_: E) => F, fg: (_: F) => G, gh: (_: G) => H, hi: (_: H) => I, ij: (_: I) => J, jk: (_: J) => K, kl: (_: K) => L, lm: (_: L) => M, mn: (_: M) => N, no: (_: N) => O, op: (_: O) => P, pq: (_: P) => Q, qr: (_: Q) => R, rs: (_: R) => S, st: (_: S) => T, tu: (_: T) => U): U;
}

Example Chaining operations with pipe 

import { Effect } from "effect"


// The Pipeable interface allows Effect values to be chained using the pipe method
const program = Effect.succeed(1).pipe(
  Effect.map((x) => x + 1),
  Effect.flatMap((x) => Effect.succeed(x * 2))
)


Effect.runSync(program) // => 4

PipeableConstructor

interface
Since v3.15.0

Constructor type for classes whose instances implement Pipeable.

When to use

Use as the constructor-side type when a class value should be known to create instances that support Effect-style method chaining with .pipe(...).

See

  • Pipeable for the instance-side contract
  • Class for the base constructor
  • Mixin for wrapping an existing class constructor

Signature

interface PipeableConstructor {
  constructor(...args: readonly Array<any>);
}

Prototypes

Prototype

Since v3.15.0

Reusable prototype that implements Pipeable.pipe.

When to use

Use when classes or object prototypes can reuse this value when they need the standard pipe implementation backed by pipeArguments.

Signature

declare const Prototype: Pipeable