Re: PKG_ADD and package loading state when called

[Andrew Janke]

On 1/18/19 4:18 PM, Mike Miller wrote:
> On Fri, Jan 18, 2019 at 15:21:59 -0500, Andrew Janke wrote:
> > I notice that when the PKG_ADD file is called, the architecture-specific
> > directory of the package has been added to the Octave path, but the main
> > package directory has not. So PKG_ADD can't call any non-octfile functions
> > in the package. Is this expected?
>
> Have you tried adding a PKG_ADD file to the "inst" directory?

That worked. Thanks!

https://github.com/apjanke/octave-addons-chrono/commit/a94887230d24a418690f14efdc095aa03e0f5266

> I agree it's not very clearly documented, but PKG_ADD can exist in any
> directory that gets added to the load path.
>
> It's more of an implementation detail of both the 'pkg load' command and
> the addpath function that the arch-specific directory is added to the
> path first, followed by the arch-independent directory.
>
> The ordering comes from the way that load_packages_and_dependencies
> passes package dirs into the addpath function.
>
> > The documentation for PKG_ADD doesn't specify what the package loading state
> > will be when PKG_ADD and PKG_DEL are called.
> > https://octave.org/doc/v4.4.1/Creating-Packages.html#Creating-Packages.
> > Could that be added?
>
> We could document that the arch-specific directory is added to the load
> path first, followed by the arch-indep directory, and turn that detail
> into an explicit documented design decision.

This sounds like a good idea, since the PKG_ADD side effects are 
dependent on it. If I find some time, I'll make a patch to add it to the 
docs.

Cheers,
Andrew