Add an option to remove unneeded parenthesis about fantomas HOT 10 CLOSED

I like the second option.

But it's tricky to make it safe. For example, you can't remove paretheses in the following pattern

List.map (fun (x, y) -> x + y)

There might be an issue with removing parentheses because we rely on matching tokens to insert comments and compiler directives in the post-processing step. I think we should keep the first option default for now.

from fantomas.

Brainstorming for this proposal:

Where can we remove parentheses safely?

• Around simple values or literals in functional application e.g. Console.WriteLine(x)
• Around tuple construction and deconstruction e.g. let (x, y) = (1, 2)
• Around tuples in patterns e.g. match (x, y) with (1, 2) -> ...

Where should we NOT remove parentheses?

• Around pattern matching of complex expressions e.g. let (Ident x) = y
• Around inline pattern matching of anonymous functions e.g. fun (x, y) -> x + y
• Around nested parentheses of units e.g. member x.Yield(()) = ...

This may suffer from unmatched token issues as #42 but it is easier to bypass (some workarounds have been implemented).

from fantomas.

We can also remove parentheses safely in DU constructors with only one field:

• let y = Some(x) -> let y = Some x ->
• math x with | Some(y) -> y -> math x with | Some y -> y

from fantomas.

This is specially important when you're generating code manually, and to be safe put parenthesis around everything, so you might get stuff like let x = (if true then "foo" else "bar")

from fantomas.

I agree it's a nice addition.

Can you take a look at this? I will take care of formatting around cursor position (part of #54).

from fantomas.

Yes, but I'll probably be only able to pick this up by the end of next week

from fantomas.

I plan to upload a new version of VS extension next week. Do you have time to work on this feature?

from fantomas.

No, I'll probably only have time for fantomas again in September

from fantomas.

Take your time. I have vacation next week, so I have more time to work on the project.

from fantomas.

In the (long) process of integrating Fantomas into FCS I will close enhancement requests like this - once things are in shape we can start to take enhancement request issues in either Microsoft\visualfsharp or FCS repo

from fantomas.