[Geany-Devel] [FT-plugins] Allowing plugins to supply filetype specific functionality

[Lex Trotman]

[...]
> I just meant for that meta tracker issue. It gets too hard to keep track of
> what's going on when there's dozens and dozens of comments. I would expect
> code-related discussions to happen on the individual PRs or separate ML
> threads.

I was thinking of the design discussion (see below) but I guess you
could make another issue for that if you want #1195 to just be a
management issue.

>
>> But everybody, please DO NOT EDIT THE SUBJECT LINE IF ON THREAD some
>> mail agents thread by subject, and DO NOT REPLY IF YOU WANT ANOTHER
>> THREAD some mail agents thread by previous ID.  We should not dictate
>> what sort of mail agent people must use to contribute, please respect
>> individual or enforced choices and follow this procedure (codebrainz
>> this should go on the issue guidelines).
>>
>
> That was the idea with the subject tag, in case there's multiple threads any
> mail client or ML archive can be searched by that, at least.

Yeah, but the mailers that thread on subject use the whole subject
line, not just a tag, so the whole subject needs to be maintained.

>
>> I agree with the approach in general, but for some major items (about
>> the process):
>>
>>> rather than endless discussions we let the code do a lot of the talking
>>
[...]
> I meant once we start implementing it, for the actual PRs. Like instead of
> saying "oh this is wrong" or "if you did it this way, ...", we could just
> provide a PR to fix it.

Well, like I said, that assumes the commenter has the time and
knowledge to do so, banning comments on the basis that the commenter
hasn't provided an alternative doesn't sound like a good idea.

>
> But just to clarify, when you say "design", can you elaborate concretely on
> what that means to you? What exact steps/process would consider that once
> complete would mean the design is done? This is a genuine question, since
> "design" is a wafty term that means different things concretely to different
> people (UML diagrams, flow charts, UI mockups, long design documents, a wiki
> page, etc).

Not this formal, see below.

>
>> codebrainz, you clearly have some design in mind, please *describe*
>> (not code) it to get the ball rolling.
>>
>
> I kind of did in the PR description, but will follow up with more specifics
> later.

Thats what I mean, the sort of thing as discussed in IRC is a start,
then API examples and examples of how the plugins would look in
different languages (again as discussed on IRC).  If you want to keep
#1195 pristine, maybe you should copy the design stuff to another
issue then.

>
>>> Code reviews are always welcome but should be accompanied by the
>>> appropriate patches/PRs/commits
>>
>>
>> Too draconian.  Just because someone has
>> questions/doubts/misunderstandings about some proposed code or design
>> doesn't mean they have the knowledge or time to immediately propose an
>> alternative.  If comments that don't have corrections/alternatives
>> proposed are ignored, nobody will review.
>>
>
> As above, I just want to avoid the PRs getting bogged down with all kinds of
> minor comments. It's a morale buster. I'm guilty of this on many occasions
> myself, which is why I put that. Mostly I just want to replace a comment
> like "you should do ..." with "if you do it like this patch ..." or "I've
> submitted a PR which does that better". Basically the idea I have is that
> anyone who is interested enough in contributing should be willing to
> contribute code/patches/examples/etc where appropriate rather than only ever
> putting comments in a text box on a webpage.

"Willing" and "able" are two different things.

Sure but many comments will be minor, and I don't think its a good use
of either the commenter or the PR owners effort when you compare:

1) the time and effort required to make a comment "typo" and the OP
making the change as they do other stuff vs

2) the commenter making another PR and the OP having to then combine those.


>
[...]
> You can submit PRs to people's PRs, it's easy.

I didn't know you could do that, how?

[...]
>> Probably sufficient for Geany to support "container lexers" and
>> flick-pass it to plugins.  But then the plugins probably have to have
>> a way to define styles similar to how `highlightmappings.h` is used
>> for included lexers.
>>
>
> It might be better to provide some kind of interface for this if we go the
> container lexer route to make it less crazy to implement. The dynamic lexer
> way is perhaps more work, but it's also more structured and one can use all
> of Scintilla's lexers as examples. Needs more research.

Yes, don't know which is better.

>
>>> Allow plugins to provide the symbols for the tagbar tree...
>>
>>
>> Do you mean the symbols pane? Or do you mean to inject symbols into
>> tagmanager so all existing functionality also sees them?
>>
>
> I mean something more like where Geany tells the plugin it wants to update
> the symbol tree and so asks the plugins for the symbols to show. It's
> sounding (from Jiří and Thomas) that using TM as a conveyance mechanism for
> this may make some sense.

Possibly, so long as its flexible enough to be able to support the
particular language symbol and scope structures, then allowing
existing code to keep accessing the symbols in the same manner has
advantages.  But, ATM it doesn't support lexical scope IIUC, the TM
experts should comment.

One very important use-case for this is in type inferred languages
which are becoming more common (Julia, rust, go, ocaml, haskell, even
C++ auto), no ctags parser is going to get types for declarations in
those (and may not even recognise `a=b` as a declaration of a) so some
external method is gonna be needed.

>
[...]
>
> Small potatoes. If the partial word is not given, many plugins will have to
> get it each themselves. It's not a big deal to do but maybe at least a
> helper function or something would be useful to avoid redundant code.

Yeah, just so long as it doesn't assume C name rules :)

[...]
> At least for the CDK (libclang) plugin I was working on, there's no
> requirement to actually run any external commands, you just call a libclang
> API function to re-compile and then use its API to extract diagnostics
> information programmatically. It would be a similar case for Python also.
> That being said, it's probably beneficial to still allow more generic
> compiler output parsing in case such nice support libraries are not
> available.

Yes, thats the idea.

>
>> General:
>>
>> I used to have a prototype of a change to load filetype specific
>> plugins specified in the filetype file.  I can't find it now (backups,
>> whats that?) but it actually was so simple that it doesn't matter.
>>
>
> I remember that. Most likely something along those lines will be a good way
> to load the plugins, though it might require to be a bit more advanced to
> deal with plugin lifetimes and other stuff.

Yes, and might be even simpler if it can take advantage of any of the
new plugin capabilities.  IIRC filetypes are never unloaded after
loading, so the plugins would have to be the same.  Possibly they
shouldn't even show in the PM, or show as not user removable.

Cheers
Lex