ReaderIO overview

Utility functions to accommodate fp-ts/ReaderIO.

Added in v0.16.0

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Table of contents

• 3 Functions
  • asksIO
  • runReaderIO

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3 Functions

asksIO

Effectfully accesses the environment outside of the Reader layer.

Signature

export declare const asksIO: <R, A>(f: (r: R) => IO<A>) => ReaderIO<R, A>

asksIO :: (r -> IO a) -> ReaderIO r a

Example

import { asksIO } from 'fp-ts-std/ReaderIO'

const lucky = asksIO<number, boolean>((n) => () => n === Date.now())

assert.strictEqual(lucky(42)(), false)

Added in v0.16.0

runReaderIO

Runs a ReaderIO and extracts the final IO from it.

Signature

export declare const runReaderIO: <R, A>(r: R) => (m: ReaderIO<R, A>) => IO<A>

runReaderIO :: r -> ReaderIO r a -> IO a

Example

import { runReaderIO } from 'fp-ts-std/ReaderIO'
import { pipe } from 'fp-ts/function'
import * as RIO from 'fp-ts/ReaderIO'

assert.strictEqual(pipe(RIO.of<string, number>(123), runReaderIO('env'))(), 123)

Added in v0.16.0