Delegates are broken up around -> which leads to illegal code #2468

Issue created from fantomas-online

Code

type some_delegate = delegate of Func<int, int> * Guid * string * Func<Func<int, int>, int> -> Func<Func<int, int>, string, string>

Result

type some_delegate = delegate of Func<int, int> * Guid * string * Func<Func<int, int>, int> ->
    Func<Func<int, int>, string, string>

Problem description

In the example here I used some nonsense delegate just to illustrate the issue. It happens whenever the delegate definition is too wide. The result is non-compilable.

As a workaround I just place these definitions (I have a bunch of them) in a separate file and ignore it. I know delegates aren't really used that much in F# anyway.

Btw, tbh, I don't really know what a "best practice" format is for delegates, but I think the easiest fix would be to simply not format them at all. Alternatively, something like this works:

type some_delegate = delegate of 
                        Func<int, int> * Guid * string * Func<Func<int, int>, int> ->
                        Func<Func<int, int>, string, string>

Another way would be this:

type some_delegate = 
    delegate of 
       Func<int, int> * Guid * string * Func<Func<int, int>, int> ->
       Func<Func<int, int>, string, string>

Extra information

• The formatted result breaks my code.
• The formatted result gives compiler warnings errors.
• I or my company would be willing to help fix this. (I'm a bit busy, but I'll try!)

Options

Fantomas master branch at 2022-08-31T07:53:05Z - 0981dfe

Default Fantomas configuration

_{Did you know that you can ignore files when formatting from fantomas-tool or the FAKE targets by using a .fantomasignore file?}