Re: emacs-tree-sitter and Emacs

[Michael Welsh Duggan]

Eli Zaretskii <address@hidden> writes:

>> From: Michael Welsh Duggan <address@hidden>
>> Cc: Stephen Leake <address@hidden>,  address@hidden
>> Date: Thu, 02 Apr 2020 10:27:23 -0400
>> 
>> > But why do you need that initial full parse in the first place?  Is
>> > parsing parts of the buffer so much harder?
>> 
>> I would think that you at least need to parse everything displayed and
>> everything before what is displayed.  (You need all prior context.  What
>> if someone opened a comment on line 1 and hasn't closed it, for
>> example?)
>
> Each buffer always knows which part of it remains unchanged.  When
> fontification is invoked, it should start from that place.  So there's
> no need to parse _all_ prior context.

Why not?  Won't it miss that hypothetical opening comment delimiter, for
example?  And, if it's because we've already parsed it before, isn't
that what we're talking about?  The initial parse?  Because after that,
of course only changes are sent to the parser.

-- 
Michael Welsh Duggan
(address@hidden)