effect-io-ai

Package: effect
Module: Result

Result.isFailure

Checks whether a Result is a Failure.

When to use

Use to narrow a known Result to the Failure variant.

Details

• Acts as a TypeScript type guard, narrowing to Failure<A, E>
• After narrowing, you can access .failure to read the error value

Example (Narrowing to failure)

import { Result } from "effect"

const result = Result.fail("oops")

if (Result.isFailure(result)) {
  console.log(result.failure)
  // Output: "oops"
}

See

• isSuccess for the opposite check
• isResult to check if a value is any Result

Signature

declare const isFailure: <A, E>(self: Result<A, E>) => self is Failure<A, E>

Source

Since v4.0.0