[Geany-devel] Function Definition

[Colomban Wendling]

Hi Jordan,

jordan a écrit :
> I'm trying to write a plug-in that among other things adds a function
> header.    Unfortunately this is also my first C program so it has been
> more of  a learning experience then anything, but I'm finally at the
> point where it sort of works.
What does your plugin, apart adding a function header? I'm curious.
And hum, I'm working on something similar to this part: a "generic"
documentation generator [1].

> Currently my plug-in reads the current line and
> breaks it down, however it's my understanding that some C programmers
> may break a function definition over several lines, in which case my
> plug-in would not work properly.
Yes. Many programmers (I'm of these) breaks function definition in
multiple line, actually I do something like this:

return_type
function_name (type arg1,
               type arg2,
               ...)

…and of course it is a little harder to naively parse (not so much in
facts, but doesn't allow what you do).

> I would also like to make it so the
> function definition for whatever the current function is would be used.
> 
> So this brings me to my questions, is there an easy way to determine if
> the current position in the editor is part of a function or not?  If so
> is there an easy way to get the function definition?  If not could
> someone maybe point me to some tutorials about parsing text in c.
As Enzo said, there is the scope to determine if a particular line is
part of a function or not, but its is not supported by every tag
generator used by Geany. What I personally chose was to walk the tag
list and find the tag closest to the current line. Tweaking this way a
bit gives quite good results.

And for the function definition, see the tag list, there is everything
you probably want (or almost). One missing thing is the argument list –
I personally chose to fix this with a regular expression, but there
might be better solutions; for example if hard-coded things are
acceptable, a custom argument parser is a somewhat easy task.

> Also currently the header that is generated by my plug-in c style multi
> line hard coded, and I was wondering if at some time more of the methods
> in templates.c would be opened up to the API? 
I don't know exactly your goals, but Geany's templates are not complete.
if I'm right: they are very simple, which is good, but doesn't support
things like loops and so (as far as I know, tell me if I'm wrong).
Since I didn't find any template parser in C, I written my own [2] for
the needs of the plugin I write. It is heavily more complex, but OTOH
more powerful… choice is not easy, is it? :D If you're interested, feel
free to use it.

Regards,
Colomban

[1] no it's not dead, you'll see soon (for those who understand ^^)
[2] http://ctpl.tuxfamily.org/ ; but if you're interested, wait for the
upcoming 0.2 release that will be somewhat different in its API. It's
almost ready and can be found in the git master.