@hackage slot-lambda0.1.0.2

Write lambdas without naming the parameters. Example:

[s| ı : ı : _ı : ı : _ı : _ı : _0 : [] |] 'a' 'b' 'c'
=  (\x y z -> x:y:y:z:z:z:x:[]) 'a' 'b' 'c'
=  "abbccca"

The unicode character ı(305) representing a 'slot' can be input in vim with the digraph 'i.'

Just import Syntax.Slot and use either [s| ... |] or [slot| ... |], which are the same thing given two names just for convenience.