diff options
Diffstat (limited to 'src/Data/Maybe')
| -rw-r--r-- | src/Data/Maybe/Properties.idr | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/Data/Maybe/Properties.idr b/src/Data/Maybe/Properties.idr index 99a3507..459cb8f 100644 --- a/src/Data/Maybe/Properties.idr +++ b/src/Data/Maybe/Properties.idr @@ -20,6 +20,11 @@ extractIsJust ItIsJust = (_ ** Refl) %inline export +extractIsNothing : {x : Maybe a} -> (0 _ : IsNothing x) -> x = Nothing +extractIsNothing ItIsNothing = Refl + +%inline +export mapIsJust : (0 f : a -> b) -> IsJust x -> IsJust (map f x) mapIsJust f ItIsJust = ItIsJust |