Fancy if-then-else with triangles!

Triangles.hs

module Triangles ((<|), (|>)) where

(<|) :: a -> Bool -> Maybe a
a <| True  = Just a
_ <| False = Nothing
infix 2 <|

(|>) :: Maybe a -> a -> a
Just a  |> _ = a
Nothing |> a = a
infix 1 |>

_green, _blue :: String
_green = "green" <| True  |> "blue"
_blue  = "green" <| False |> "blue"