Operator >>.~ incorrectly formatted

[CPardi]

I have found that the operator >>.~ is incorrectly changed to >> after formatting. The example below

module Scratch

let (>>.~) (g : int) (h : int) : int = g + h
let output = 2 >>.~ 3

results in the following:

module Scratch

let (>>) (g : int) (h : int) : int = g + h
let output = 2 >> 3

This happens when using the online formatting tool and the version 2.8.0 Nuget package.

Thanks,
Chris

[jindraivanek]

When investigating this bug, I ended up on an unexpected place :)

It turns out that it is caused by tokenizer, which output >> and rest of operator is thrown out. Same behavior for operators like >>...... or >>.^^^~. Guessing from comments in FSharp.Compiler.Service code https://github.com/fsharp/FSharp.Compiler.Service/blob/79e77bbf75666d980ee105f3e305ba7803f834dd/src/fsharp/service/ServiceLexing.fs#L606, https://github.com/fsharp/FSharp.Compiler.Service/blob/79e77bbf75666d980ee105f3e305ba7803f834dd/src/fsharp/service/ServiceLexing.fs#L627 and https://github.com/fsharp/FSharp.Compiler.Service/blob/79e77bbf75666d980ee105f3e305ba7803f834dd/src/fsharp/service/ServiceLexing.fsi#L207 - problem will be with any operator containing >.

It looks like a bug in F# tokenizer, but maybe its just state of things and we need to workaround it.

I will create an issue in FSharp.Compiler.Service, meanwhile I have workaround PR prepared.

[CPardi]

Hi jindraivanek, thanks for looking into this.
It's interesting that the bug stems from FSharp.Compiler.Service. I use the Rider IDE, which is built on top of FSharp.Compiler.Service, and in newer versions has trouble highlighting files when I use this operator. I know nothing about the FSharp.Compiler.Service but this being a bug there would explain why this operator causes problems for both Fantomas and Rider.

[nojaf]

Should be fixed in 2.8.1.