Variable isSome`Const`

isSome: <A>(fa: Option<A>) => fa is Some<A>

Returns true if the option is an instance of Some, false otherwise.

Type Declaration

- <A>(fa: Option<A>): fa is Some<A>
- Type Parameters
  - A
  Parameters
  - fa: Option<A>
  Returns fa is Some<A>

Example

import { some, none, isSome } from 'fp-ts/Option'

assert.strictEqual(isSome(some(1)), true)
assert.strictEqual(isSome(none), false)

Since

2.0.0