Re: IDE

[Eric Ludlam <eric@siege-engine.com>]

On 10/10/2015 04:59 AM, Dmitry Gutov wrote:
> On 10/10/2015 11:30 AM, Eli Zaretskii wrote:
>
>> I was talking about working on IDE, not on completion.  And for the
>> most popular languages in the industry, not just for some a few niche
>> languages.
>
> You quoted the message that said "accurate code completion and powerful
> refactoring support". I can agree that the latter is barely touched (*),
> but it looked like you ignored the former.
>
>> Let's not reiterate past discussions: you forget CEDET.
>
> I was enumerating external programs. But sure, CEDET is a yet another
> option for completion. Though not too "accurate" one, if we're talking
> anything but C.

I had always intended CEDET to be a baseline for IDE like features. 
Looking just at tagging files, those familiar with it's internals 
recognize that it can use external tools as weak as ctags or GLOBAL, and 
can use a more powerful external tool for parsing as well, such as using 
JAVAC for decompiling .jar files into tags.  As a backup, it also has 
in-buffer parsing for when you've only half-written your code, or when 
no external tool is available.

The same philosophy is throughout CEDET.  Unfortunately, those who are 
interested in tooling who brush casually past CEDET only see that people 
complain that it doesn't always complete right, or that the C++ part is 
hard to setup, and don't see that the cool piece they want integrated 
into Emacs could use CEDET as a framework.

A side effect is that every completion engine out there has a custom way 
of integrating random tools in.  In theory, completion engines could 
call into CEDET, and let CEDET dispatch to the other tools.  In that 
world, bootstrapping new tools is simpler with only one backend to worry 
about, and there would be more language independent creativity for IDE 
like features.

If we look at the two starting key features listed for IDEs, 
"completion" and "refactoring", the basics are all there.  CEDET has a 
completion engine, but it is only as good as the input data.  If better 
external tools (like GCC) or easier to configure tools could feed it, it 
would be more accurate.  CEDET also has 'srecode' which is about 
generating code.  This bit is trickier, as the intention is you could 
write one highlevel tool that might extract tag data from your file, 
permute the language-independent tags, and then write them back out with 
srecode.  There are tests showing this working, but they are simple and 
proof of concept and not stuff someone would depend on day-to-day.

What it needs is folks who care about cross language tooling, and not 
just the language specific part.  While I continue to maintain CEDET, I 
don't code for a living anymore, so do not run into CEDET's rough 
corners enough to know to fix them.

Eric