effect-io-ai

Package: effect
Module: Predicate

Predicate.mapInput

Transforms the input of a predicate using a mapping function.

When to use

Use when you have a predicate on A and want to check B values by mapping each B to an A, such as checking lengths or projections.

Details

Returns a new predicate that applies f before self. There is no additional short-circuiting beyond what self does.

Example (Checking string length)

import { Predicate } from "effect"

const isLongerThan2 = Predicate.mapInput((s: string) => s.length)(
  (n: number) => n > 2
)

console.log(isLongerThan2("hello"))

See

• Predicate
• and
• not

Signature

declare const mapInput: { <B, A>(f: (b: B) => A): (self: Predicate<A>) => Predicate<B>; <A, B>(self: Predicate<A>, f: (b: B) => A): Predicate<B>; }

Source

Since v2.0.0