Infix.elm

{-| Helper function to partially apply an "infix" a function. Same as flip but is more comprehensable for some cases, imho.

Unfortunatly you can not to partial function application with infix functions, let a lone use any function as infix.

So this is not possible in elm, which is unfortunate because the Haskell way is much more tacit.

    -- Haskell, not possible in elm
    List.map (- 10) [ 10, 20, 30 ] --> [0,10,20]

    -- Purecript, not possible in elm
    List.map (_ - 10) [ 10, 20, 30 ] --> [0,10,20]

    -- Substract 10. Reads as if the `-` is actually partially applied the infixed way like in the haskell example.
    -- It also losely resembleds purescripts anonymous function arguments
    List.map (i_ (-) 10) [ 10, 20, 30 ]
    --> [0,10,20] : List number

    -- Does the same as before, but is harder to comprehend
    List.map (flip (-) 10) [ 10, 20, 30 ]
    --> [0,10,20] : List number

    -- Without "correction", accidently substract x from 10.
    List.map ((-) 10) [ 10, 20, 30 ]
    --> [0,-10,-20] : List number

    -- Substract 10, without any helpers. Very noisy.
    List.map (\x -> x - 10) [ 10, 20, 30 ]
    --> [0,-10,-20] : List number

-}
i_ : (c -> b -> a) -> b -> c -> a
i_ =
    flip


flip : (c -> b -> a) -> b -> c -> a
flip a b c =
    a c b


{-| Examples used in the description
-}
examples : List (List number)
examples =
    -- Substract 10. Reads as if the `-` is actually partially applied the infixed way like in the haskell example.
    -- It also losely resembleds purescripts anonymous function arguments
    [ List.map (i_ (-) 10) [ 10, 20, 30 ] --> [0,10,20] : List number

    -- Does the same as before, but is harder to comprehend
    , List.map (flip (-) 10) [ 10, 20, 30 ] --> [0,10,20] : List number

    -- Substract 10, without any helpers. Very noisy.
    , List.map (\x -> x - 10) [ 10, 20, 30 ] --> [0,-10,-20] : List number

    -- Without "correction", accidently substract x from 10.
    , List.map ((-) 10) [ 10, 20, 30 ] --> [0,-10,-20] : List number
    ]