idris type-directed overloading

Overloading.idr

f : String -> String
f x = x ++ "!"

namespace maybe
    f : Maybe String -> String
    f (Just x) = x ++ "!"
    f Nothing = "_"


test1 : String
test1 = f "foo"

test2 : String
test2 = f (Just "bar")

test3 : String
test3 = f Nothing