[Ur] Functional infix operators ?

[Gabriel Riba]

A functional language cannot lack functional infix operators :)

They enhance code readability and save parenthesis.

The reverse functional application, which I like the most, gives a data
navigation aspect

   val expr = xs |> filter isEven
                 |> map double
                 |> foldl myop z
                 |> show

The left-to-right composition shows the composition as a sequence.

   In Haskell (with Arrow operators from Data.Category)):

   rebalance = decreaseLevel >>> skew >>> skewRight >>> skewRightRight >>>
split >>> splitRight

Haskell's backtick quoting converts any function in infix. (Scala does it
without backticks)

   val rebalance = decreaseLevel `andThen` skew `andThen` skewRight

Others operators:

* Functional aplication (forward and reverse)

OCaml (@@) and (|>)
http://caml.inria.fr/pub/docs/manual-ocaml/libref/Pervasives.html#6_Compositionoperators

FSharp (<|) and (|>) https://msdn.microsoft.com/en-us/library/dd233228.aspx
Haskell ($) and (proposed (.$))
Elm (<|) and (|>)  http://elm-lang.org/learn/Syntax.elm

* Functional composition (right-to-left and left-to-right)

Standard ML (o)
Haskell ( . )
FSharp (<<) and (>>)
OCaml Batteries (%) and (%>) 
http://ocaml-batteries-team.github.io/batteries-included/hdoc2/BatPervasives.html

Haskell Category (<<<) and (>>>)
Scala (compose) and (andThen)