egison-4.0.0: test/lib/core/maybe.egi

--
-- Maybe
--

assertEqual "nothing pattern and Just"
  (matchAll Just 1 as maybe integer with
    | nothing -> "error")
  []

assertEqual "just pattern and Just"
  (matchAll Just 1 as maybe integer with
    | just $x -> x)
  [1]

assert "nothing pattern and Nothing"
  (match Nothing as maybe integer with
    | nothing -> True)

assertEqual "just pattern and Nothing"
  (matchAll Nothing as maybe integer with
    | just $x -> "error")
  []