bug#73376: Treesitter does not rescan after indentation

bug#73376: Treesitter does not rescan after indentation

[pranshu sharma]

After indenting, treesitter does not rescan the region.  This causes
errors in the concrete syntax tree, which mess up indentation and syntax
colouring.

The issue I'm having is kind of hard to explain, but in a summary I have
the poorly indented code, where what's between '_'(which is not in the
code itself) is coloured:
---------------
f x =
               let _a_ = 2
                   _c_ = 1
  in a
--------------
Then when I indent it with haskell-ts-mode, I get:
---------------
f x =
  let _a_ = 2
      c = 1
  in a
--------------
When the 2 snippets of code have the exact same meaning.  If I revert
the buffer then the 'c' becomes coloured again.

This is not just problem with syntax highlighting, but if I was to
indent the 2nd snippet it would mess it up, as it has the wrong CST.

bug#73376: Treesitter does not rescan after indentation

[Yuan Fu]

> On Sep 20, 2024, at 12:00 AM, pranshu sharma <pranshusharma366@gmail.com> wrote:
> 
> 
> After indenting, treesitter does not rescan the region.  This causes
> errors in the concrete syntax tree, which mess up indentation and syntax
> colouring.
> 
> The issue I'm having is kind of hard to explain, but in a summary I have
> the poorly indented code, where what's between '_'(which is not in the
> code itself) is coloured:
> ---------------
> f x =
>               let _a_ = 2
>                   _c_ = 1
>  in a
> --------------
> Then when I indent it with haskell-ts-mode, I get:
> ---------------
> f x =
>  let _a_ = 2
>      c = 1
>  in a
> --------------
> When the 2 snippets of code have the exact same meaning.  If I revert
> the buffer then the 'c' becomes coloured again.
> 
> This is not just problem with syntax highlighting, but if I was to
> indent the 2nd snippet it would mess it up, as it has the wrong CST.
> 

Hi Pranshu,

Thanks for the report. I can reproduce it. Let me see what’s going on here.

Yuan

bug#73376: Treesitter does not rescan after indentation

[Yuan Fu]

> On Sep 20, 2024, at 9:20 PM, Yuan Fu <casouri@gmail.com> wrote:
> 
> 
> 
>> On Sep 20, 2024, at 12:00 AM, pranshu sharma <pranshusharma366@gmail.com> wrote:
>> 
>> 
>> After indenting, treesitter does not rescan the region.  This causes
>> errors in the concrete syntax tree, which mess up indentation and syntax
>> colouring.
>> 
>> The issue I'm having is kind of hard to explain, but in a summary I have
>> the poorly indented code, where what's between '_'(which is not in the
>> code itself) is coloured:
>> ---------------
>> f x =
>>              let _a_ = 2
>>                  _c_ = 1
>> in a
>> --------------
>> Then when I indent it with haskell-ts-mode, I get:
>> ---------------
>> f x =
>> let _a_ = 2
>>     c = 1
>> in a
>> --------------
>> When the 2 snippets of code have the exact same meaning.  If I revert
>> the buffer then the 'c' becomes coloured again.
>> 
>> This is not just problem with syntax highlighting, but if I was to
>> indent the 2nd snippet it would mess it up, as it has the wrong CST.
>> 
> 
> Hi Pranshu,
> 
> Thanks for the report. I can reproduce it. Let me see what’s going on here.
> 
> Yuan

Seems to be a tree-sitter or tree-sitter-haskell bug, reported here: https://github.com/tree-sitter/tree-sitter-haskell/issues/129

Yuan

bug#73376: Treesitter does not rescan after indentation

[pranshu sharma]

Ok, keep us updated if any progress is made