Add syntactic (_ + 1) sugar for functions ala Scala/Clojure

[baronfel]

Submitted by Khan Thompson on 3/21/2014 12:00:00 AM
37 votes on UserVoice prior to migration

Add in shorthand syntax for anonymous functions, even if it is only for single argument functions.
For example:

[1; 2; 3; 4] |> List.map (_ + 1)

As opposed to

[1; 2; 3; 4] |> List.map (fun i -> i + 1)

It would be great to have this shorthand so that our anonymous functions are shorter than the C#ers' :).

Original UserVoice Submission
Archived Uservoice Comments

[charlesroddie]

Presumably g(f(_+1)) would mean g(f(fun i -> i+1)), resolving to the closest brackets, but g(f <| _+1) would mean g(fun i -> f(i+1)). People would find this confusing. It will be hard to find a bracketing rule that is both consistent and unsurprising. Even something simple like (_+(1+_)) I believe would generate a lot of interpretations. If the notation didn't use round brackets then this problem would go away, but F# currently restricts itself to ascii characters and all the suitable ones got taken straight away.

Some suggestions in #168 are intermediate approaches to the same problem (shorter syntax for fun x ->) which are more readable and don't give the same ambiguities.

[dsyme]

Treating this as a duplicate of #634