Function

Some useful utils.

API

lazy

Lazy<A> = () => A

Creates a lazy function.

lazy(1) ➔ () => 1

noop

() => void

A no-operation funciton.

noop() ➔ undefined

identity

<A>(a: A) => A

Identity.

identity(1) ➔ 1

constant

<A>(a: A) => Lazy<A>

A thunk returns self.

constant(1)() ➔ 1

constTrue

Lazy<boolean>

A thunk returns always true.

constTrue() ➔ true

constFalse

Lazy<boolean>

A thunk returns always false.

constFalse() ➔ false

constNull

Lazy<null>

A thunk returns always null.

constNull() ➔ null

constUndefined

Lazy<undefined>

A thunk returns always undefined.

constUndefined() ➔ undefined

constVoid

Lazy<void>

A thunk returns always void.

constVoid() ➔ undefined

isNullable

(a: unknown) => a is null | undefined

Returns whether the value is null or undefined.

isNullable(null)      ➔ true
isNullable(undefined) ➔ true
isNullable(0)         ➔ false

isNonNullable

// Exclude null and undefined from T
type NonNullable<T> = T & {}
<A>(a: A) => a is NonNullable<A>

Returns whether the value is NonNullable.

isNonNullable(null)      ➔ false
isNonNullable(undefined) ➔ false
isNonNullable(0)         ➔ true