bug#59686: 30.0.50; tree-sitter indentation in some loops and conditional statements is wrong

[Theodor Thornhill]

On 3 December 2022 11:48:34 CET, Yuan Fu <casouri@gmail.com> wrote:
>
>Theodor Thornhill <theo@thornhill.no> writes:
>
>> Bruce Stephens <bruce.stephens@isode.com> writes:
>>
>>> On 02/12/2022 08:39, Eli Zaretskii wrote:
>>>
>>>> FWIW, this is an unusual style, so I see no catastrophe if it is not 110%
>>>> according to expectations.  Users can easily fix that by tweaking their 
>>>> BOLs
>>>> where important.
>>>
>>>
>>> The example I gave would be unusual, I think, but I'd argue that the
>>> situations where I saw the problem are quite natural.
>>>
>>> For example,
>>>
>>>                  } else if ( MYSTRCMP (attname, SOME_PREFIX_X400ADDRESS) ||
>>>                              MYSTRCMP (attname, SOME_PREFIX_X400) ) {
>>>                      FOO_ptr orp = foo_std2foo (val);
>>>
>>> or a function declaration with several arguments with types that are
>>> rather long.
>>>
>>> I agree it's not a critical bug but if there's no appropriate general
>>> fix it would be helpful to have some guidance for users to resolve our
>>> specific cases.
>>
>> This is the case I was thinking of.  In the for-loop a grand-parent-bol
>> on compound_statement rule would match the 'for' keyword, so the
>> indentation will be correct, but this one will not, IIRC.  I plan to dig
>> into this some more soon, but motivation left me a little on that issue.
>> Maybe we could make a preset like:
>>
>> ```
>> (seq
>>  (parent-is "compound_statement") parent (parent-is "for_statement") bol)
>> ```
>>
>>
>> In other words, make other presets execute sequentially, move point,
>> check again, and if all are true, pick indent offset.  Or allow multiple
>> captures, like so:
>>
>> ```
>> (for_statement @offset-anchor
>>   body: (compound_statement (_) @to-indent))
>> ```
>>
>> Here the @to-indent capture would get the new indent level based on
>> treesit-node-start of for_statement.
>>
>> What do you think, Yuan?
>
>I think we can just test for the grandparent, there is an
>(undocumented) matcher n-p-gp which matches parent and grandparent.
>
>Yuan

Yeah I know, but that doesn't work in every case we see this behavior.