/Prelude-v23.0.0/Optional/any.dhall

Copy path to clipboard

Returns True if the supplied function returns True for a present element and False otherwise

Examples

any Natural Natural/even (Some 2) ≡ True
any Natural Natural/even (None Natural) ≡ False

Source

{-|
Returns `True` if the supplied function returns `True` for a present element and
`False` otherwise
-}
let any
: ∀(a : Type) → (a → Bool) → Optional a → Bool
= λ(a : Type) →
λ(f : a → Bool) →
λ(xs : Optional a) →
merge { Some = f, None = False } xs

let example0 = assert : any Natural Natural/even (Some 2) ≡ True

let example1 = assert : any Natural Natural/even (None Natural) ≡ False

in any