13 lines
394 B
Text
13 lines
394 B
Text
|
--| Convert an `Optional` value into the equivalent `List`
|
||
|
|
let toList
|
||
|
|
: ∀(a : Type) → Optional a → List a
|
||
|
|
= λ(a : Type) →
|
||
|
|
λ(o : Optional a) →
|
||
|
|
merge { Some = λ(x : a) → [ x ] : List a, None = [] : List a } o
|
||
|
|
|
||
|
|
let example0 = assert : toList Natural (Some 1) ≡ [ 1 ]
|
||
|
|
|
||
|
|
let example1 = assert : toList Natural (None Natural) ≡ ([] : List Natural)
|
||
|
|
|
||
|
|
in toList
|