Idempotency problem related to comments in `with`

[Smaug123]

Issue created from fantomas-online

Formatted code

namespace Foo

module Foo =
    let a =
        try
            failwith ""
        with
        // hi!
        :? Exception as e -> failwith ""

Reformatted code

namespace Foo

module Foo =
    let a =
        try
            failwith ""
        with
            // hi!
            :? Exception as e -> failwith ""

Problem description

Fantomas was not able to produce the same code after reformatting the result.

This looks like being #1647 again, maybe?
I still think the right answer here is to retain the | character, though.

Extra information

• The formatted result breaks by code.
• The formatted result gives compiler warnings.
• I or my company would be willing to help fix this.

Options

Fantomas 4.4.0

    { config with
                SpaceBeforeColon = true
                SpaceBeforeSemicolon = true
                IndentOnTryWith = true }

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

[nojaf]

This looks indeed like #1647 but with as e as a slight deviation.

I still think the right answer here is to retain the | character, though.

Yeah, working on that part from a style guide point of view first.

• https://docs.microsoft.com/en-us/dotnet/fsharp/style-guide/formatting#formatting-trywith-expressions
• https://docs.microsoft.com/en-us/dotnet/fsharp/style-guide/formatting#formatting-discriminated-union-declarations
• Prefer bars in single-case DU G-Research/fsharp-formatting-conventions#26

I'll create a follow-up issue to tackle the style change.