Re: Tree sitter: issue embedding HTML, CSS, JavaScript within a new php-ts-mode

[Simon Pugnet <simon@polaris64.net>]

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Yuan Fu <casouri@gmail.com> writes:

> Hey Simon,
>
> Thanks for trying this out! Feedbacks like this are very welcome.

Hi Yuan, you're very welcome! I'm glad to be able to help.


>> On Feb 9, 2023, at 4:45 AM, Simon Pugnet <simon@polaris64.net> 
>> wrote:
>> 
>> 1. Based on my rules for embedding ='html= within ='php= above, 
>> should I expect ~(treesit-language-at (point))~ to return ='php= 
>> when the point is within a PHP region?
>
> Because we don’t have much experience with tree-sitter and its
> interfaces, I made treesit-language-at simply delegate work to
> treesit-language-at-point-function, which can be an arbitrary
> function, giving developers maximum flexibility. You need to set 
> that
> variables to a function, otherwise treesit-language-at simply 
> returns
> the first parser in the parser list.

Ah, that makes sense, thank you. I must have missed that in the 
documentation as I thought this was just used when overriding the 
default behaviour.

I've added the following implementation and this appears to work 
nicely: -

  (defun php-ts--language-at-point (point)
    "Return the language at POINT, used to determine which tree sitter 
    parser to use."
  
    (let* ((php-node-at-point (treesit-node-at point 'php))
           (parent-node (treesit-node-parent php-node-at-point)))
      (if (and (string-equal "text" (treesit-node-type 
      php-node-at-point))
               (or (string-equal "program" (treesit-node-type 
               parent-node))
                   (string-equal "text_interpolation" 
                   (treesit-node-type parent-node))))
          'html
        'php)))

The next step will be to run further tests on the current node in 
cases where the language is 'html in order to determine if the actual 
language is 'css or 'javascript.


>> 2. Is my goal of embedding HTML within PHP, then embedding CSS and 
>> JavaScript/TypeScript within HTML feasible and if so am I going 
>> about this in the right way?
>
> It should be. Although I didn’t thought of having multiple layers of
> embedded language (in this case PHP embedding HTML embedding
> CSS/Javascript), if you order the entries in treesit-range-rules 
> like
> you do now (outer most host language, then embedded language, then
> embedded embedded language), it should work. Try setting
> treesit-language-at-point-function and it should work right. If not…
> then we need to look into it.

I'll try this next and I'll be sure to let you know how it goes.


Thanks for your advice, and kind regards,

-- 
Simon Pugnet
https://www.polaris64.net/

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