Re: Semantic font-lock for Java

[Eli Zaretskii <eliz@gnu.org>]

> From: David Engster <deng@randomsample.de>
> Cc: Eli Zaretskii <eliz@gnu.org>,  emacs-devel@gnu.org
> Date: Tue, 28 Jan 2020 18:21:09 +0100
> 
> > Perfect explanation David. Though I'll add that parsing is not
> > terribly slow. It's usable. Here's a demo video showcasing the same 
> > https://youtu.be/4UcPIdTJLOM .
> 
> Note that Semantic will cache the AST between sessions, so if you've
> loaded that file before, it will just load the cache.
> 
> The time needed for parsing varies wildly between languages. The Java
> parser is one of the faster ones, because it's an LALR parser, which is
> more efficient than LL (which Semantic uses for C and C++). It is also
> very old, and at that time (around Java 1.4 or so) the language was
> still very easy to parse (it doesn't support generics, for instance).

Thanks.  I'd be interested to see the times of showing the first
windowful of a Java file visited for the first time, and then the same
file visited again, first unchanged, and then with some small changes
in the first windowful.  Comparisons of these times with the default
font-lock would be useful for assessing the feature.  (If the same can
be done for C/C++, that's be better yet.)