lambda-placeholders is a Haskell library to emulate the placeholders feature of Scala.

Background

• Placeholders in Scala act similar to those used in category theory.
• Rather than create a lambda or name a function, an underscore is used in place of a parameter and the function is abstracted over that location.
• This placeholders library doesn't use underscores, rather it leverages similar capabilities found in TupleSections.
• A description of Scala placeholders can be found here.

Example

{-# LANGUAGE
 TupleSections
 #-}
module Main where
import Language.LambdaPlaceholders
foo (a,b,c) = a + b + c
curried_foo = foo.$.(2, , )
main = do
    putStrLn $ show $ curried_foo 4 5