>>> findIndex isSpace "Hello World!" Just 5
>>> findIndex odd [0, 2, 4, 6] Nothing
>>> findIndex even [1..] Just 1
>>> findIndex odd [0, 2 ..] * hangs forever *
>>> findIndices (`elem` "aeiou") "Hello World!" [1,4,7]
>>> findIndices (\l -> length l > 3) ["a", "bcde", "fgh", "ijklmnop"] [1,3]
>>> bifind even (27, 53) Nothing
>>> bifind even (27, 52) Just 52
>>> bifind even (26, 52) Just 26Empty structures always yield Nothing:
>>> bifind even (BiList [] []) Nothing