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

[Lex Trotman]

Not sure I agree that Github is bad for *development* discussions, for
users, sure, the ML is likely to find the audience better, but most
developers will also be githubians. Also github supports markup that
mail doesn't.  But anyway lets try mailing it in for this issue, and
see how it goes.

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).

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

No, not yet, we need to agree what we are going to code.  This is a
major change to Geany's design, and it should be designed, not just
jump into coding it.  Geany suffers from too much "heres some code I
made earlier".

codebrainz, you clearly have some design in mind, please *describe*
(not code) it to get the ball rolling.

> 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.

Using a branch is good, but, as PRs cannot be layered on PRs, what
process do you suggest for corrections to be proposed?  And how will
alternatives be compared? More than one PR cannot be committed at the
same time, and "first PR gets committed" is a bad recipe for new
designs, the first is often the worst.  Having later PRs have to
revert previous PRs just makes them more complex and harder to review
so better proposals tend to be rejected.

On the requirements, not much to say, agree in principle.  Minor
comments/suggestions:

> Allow plugins to provide syntax highlight.

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.

> 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?

> provide the auto-complete list, given the current location in the document and the part of the word already typed.

Location in document is probably enough, the plugin probably has to
check for preceeding context `aaa.bbb.ccc` anyway, so the partially
typed name is no issue, and it can then be language specific, like
lisp can include *s and -s and other things that C doesn't allow in
names.

> plugins to hook into the build system runner

Plugins can now get and set any build command, not sure what else is
needed, except maybe a way of telling Geany to not save the plugin set
values, since the plugin is handling them.

> plugins to provide diagnostics when build commands are run.

Allowing the plugin to parse the command response *before* it goes in
the message window would be good.

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.

Finally despite some disagreements on detail, the general idea and
process is good (IMNSHO), thanks to codebrainz for starting the
process.

Cheers
Lex