Re: Tree-sitter documentation

[Yuan Fu]

> On Nov 7, 2022, at 4:11 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Mon, 7 Nov 2022 02:13:20 -0800
>> 
>>> This function takes a series of @var{query-spec}s, which are triplets
>>> @w{@code{@var{:keyword} @var{value} @dots{} @var{query}}}.  Each
>>> @var{query} is a tree-sitter query in either the string, s-expression
>>> or compiled form.
>>> 
>> Is is ok to use “triplets” here? Because there can be more than one pair of 
>> :keyword and values before a query, eg,
>> 
>> :keyword value
>> :keyword value
>> query
> 
> In that case, "triplets" is definitely incorrect, but I had no way of
> understanding that this is possible.
> 
> It should be possible top describe this kind of argument list, but
> does it really have to be so complicated?  These are not internal
> functions, so Lisp programmers will have to battle with this signature
> all the time.  Can we make the function's signature easier to
> document, understand, and use?
> 
> For example, what about accepting an alist as the argument, where each
> alist element specifies a query and its keyword/value pairs that
> customize the query?

Alists has too much layers of parenthesizes that is verbose and easy to get 
wrong. Compare:

(treesit-font-lock-rules
 :language 'python
 :override t
 :feature 'string
 '((string :anchor "\"" @python--treesit-fontify-string)
   (string) @contextual)

 :feature 'string-interpolation
 :language 'python
 :override t
 '((interpolation (identifier) @font-lock-variable-name-face)))

With

(treesit-font-lock-rules
 '((((string :anchor "\"" @python--treesit-fontify-string)
     (string) @contextual)
    (language . python)
    (override . t)
    (feature . string))

   (((interpolation (identifier) @font-lock-variable-name-face))
    (language . python)
    (override . t)
    (feature . string-interpolation))))


Yuan