bug#66845: 29.1; cmake-ts-mode indentation broken

[Yuan Fu]

> On Nov 7, 2023, at 9:21 AM, Randy Taylor <dev@rjt.dev> wrote:
> 
> On Tuesday, November 7th, 2023 at 03:25, Yuan Fu <casouri@gmail.com> wrote:
>> IMO it makes more sense to use prev-sibling:
>> 
>> ,@(ignore-errors
>> (treesit-query-capture 'cmake '((body) @capture))
>> `(((parent-is "body") prev-sibling 0)))
>> 
>> This would allow users to manually adjust the indentation of a line and have 
>> the rest of the body follow that.
> 
> This would be much more elegant but unfortunately that and my previous patch 
> failed to account for the following:
> 
> 1 if(TRUE) # Comment.
> 2 endif()
> 
> And place POINT at the end of line 1 and hit RET. It will indent to the start 
> of the comment :(. However, you gave me an idea: use the grand-parent as the 
> anchor (which in this case is the if - exactly what we want). I've attached a 
> new patch which accounts for that.

Ah, I was a bit rusty too. The approach I mentioned should also have a rule for 
the first sibling which anchors on the parent, while the rest siblings anchor 
on the previous sibling. But anchoring all on the parent is equally valid.

> 
> Juan, thanks for testing the first patch. Please give this new one a whirl if 
> you're able to.
> 
>> 
>> As for why parent-bol returns the BOL of the comment line, that’s expected: 
>> The parent is body, and body starts at the comment, so of course the 
>> beginning of the parent line is the beginning of the comment line. In the 
>> image below, the highlighted portion marks the body node.
>> 
>> Some tree-sitter grammar would mark the beginning of body at the end of 
>> if(TRUE), but what tree-sitter-cmake does here is equally valid.
> 
> Thanks, I understand what's happening now. Whenever line_comment is NOT the 
> first child, the beginning of body is at the end of if(TRUE). If line_comment 
> is the first child, then the beginning of body is at the start of the 
> comment. I was expecting them to behave the same - that's why I was so 
> confused, and I don't really understand why it was done that 
> way.<0001-Fix-cmake-ts-mode-indentation-Bug-66845.patch>

You’re right. That’s a strange behavior. We should probably report to 
tree-sitter-cmake.

Yuan