effect-io-ai

Package: effect
Module: Result

Result.tap

Runs a side-effect on the success value without altering the Result.

Details

• If the result is a Success, calls f with the value (return value is ignored)
• If the result is a Failure, f is not called
• Returns the original Result unchanged (same reference)
• Useful for logging, debugging, or performing mutations outside the Result chain

Example (Logging a success value)

import { pipe, Result } from "effect"

const result = pipe(
  Result.succeed(42),
  Result.tap((n) => console.log("Got:", n))
)
// Output: "Got: 42"

console.log(Result.isSuccess(result))
// Output: true

See

• map to transform the success value

Signature

declare const tap: { <A>(f: (a: A) => void): <E>(self: Result<A, E>) => Result<A, E>; <A, E>(self: Result<A, E>, f: (a: A) => void): Result<A, E>; }

Source

Since v4.0.0