Bug: Slice parameters are tokenized as part of the function itself

[Duckapple]

Describe the bug
Slice parameters are tokenized as part of the function itself

To Reproduce
Steps to reproduce the behaviour:

1. Insert the following test into a text file (the other numbers in the screenshot are to demonstrate the color they should have):

let test1 (word: char list) = List.rev word[0 .. 1]

Expected behaviour
I would expect the numbers to still be highlighted as numbers, though I think parsing them as expressions is the correct move.

Screenshots

Environment (please complete the following information):

• OS: Linux (6.1.6-arch1-1)
• Ionide version: v7.4.0
• VSCode version: 1.74.3
• dotnet SDK version: 7.0.102
• mono / .Net Framework version: (didn't know how to check / probably not relevant?)

Additional context
I would fix this myself, but I don't have the expertise with TextMate grammars I'd probably need.
It also seems like GitHub gets this part right with its grammar.

[MangelMaxime]

Hello,

Looking at the inspector I think the problem is not in the fsgrammar but in the semantic highlighter. The code responsible for the semantic highlight is hosted in https://github.com/fsharp/FsAutoComplete and can sometimes need a fix in https://github.com/dotnet/fsharp.

@baronfel Am I right to say the problem is in the semantic highlighter ?

[baronfel]

yeah, that's right - anything in the semantic token type is FSAC, textmate tokens are this repo.

FSAC is pretty much a straight pass-through of the semantic highlighting from the FSharp.Compiler.Service library - so it's likely that any real fix would end up in dotnet/fsharp eventually.