Re: Plug treesit.el into other emacs constructs

[Theodor Thornhill]

On 15 December 2022 00:31:20 CET, Yuan Fu <casouri@gmail.com> wrote:
>
>
>> On Dec 14, 2022, at 6:01 AM, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
>> 
>>> I would argue that the purpose of forward-sexp is to move over items in
>>> a list.
>> 
>> There are different ways to look at it.  In the Lisp context where it
>> emerged, we only have "identifiers" and "parenthesized thingies", so
>> that doesn't give much guidance about what to do in-between.
>
>I see, so maybe sexp means the general, flexible AST entity. And thinking of 
>it, my idea is just forward-list :-) And we definitely should include 
>forward-list into the list of navigation commands we want to support, among 
>the ones that are already brought up.
>
>> 
>> The semantics I chose for SMIE is what I found to be closest to
>> past practice.
>
>That’ great! You’ve done all the experiments and thinking, and all I need to 
>do is to understand it ;-)
>

Are you working on this, yuan? If so I'll get out of your hair.

>>> But if we move over the smallest
>>> subtree, I’d imagine it only move across the semicolon after [1].
>> 
>> In my view ";" is not a substree.  It's the node of a substree.
>> We can't actually move over a proper subtree in that case because there
>> is no substree whose left boundary starts right before the ";", so the
>> closest is to move over the ";" *plus* its right child.
>
>Ah, so by “smallest subtree” you basically mean “smallest non-leaf node”? Is 
>the following logic what you have in mind?
>
>forward-sexp:
>Among all nodes that starts right after point:
>1. if we can find a smallest non-leaf node
>   -> skip over it
>2. if we can only find leaf node
>   -> go to the end of the immediate (smallest) parent node
>      that covers point, and skip over its next sibling (by recursively 
> applying either 1 or 2)
>
>Yuan