effect-io-ai

Package: effect
Module: Option

Option.liftNullishOr

Lifts a function that may return null or undefined into one that returns an Option.

When to use

Use to wrap existing nullable-returning functions for use in Option pipelines

Details

• Calls the original function with the given arguments
• Wraps the result via fromNullishOr

Example (Lifting a parser)

import { Option } from "effect"

const parse = (s: string): number | undefined => {
  const n = parseFloat(s)
  return isNaN(n) ? undefined : n
}

const parseOption = Option.liftNullishOr(parse)

console.log(parseOption("1"))
// Output: { _id: 'Option', _tag: 'Some', value: 1 }

console.log(parseOption("not a number"))
// Output: { _id: 'Option', _tag: 'None' }

See

• fromNullishOr for converting a single value
• liftThrowable for functions that throw instead

Signature

declare const liftNullishOr: <A extends ReadonlyArray<unknown>, B>(f: (...a: A) => B) => (...a: A) => Option<NonNullable<B>>

Source

Since v4.0.0