Re: Questions regarding modules

[Marius Kjeldahl <marius dot kjeldahl at gmail dot com>]

I did figure out that (require "HelloKawa.scm") also works, but I
still do not understand why the short form (HelloKawa:hello) works,
but not (net.kjeldahl.kawatest.app.HelloKawa:hello) which is the
full/proper name for that module (at least that's what I'm trying).

Thanks,

Marius K.


On Sat, Mar 1, 2014 at 4:52 PM, Marius Kjeldahl
<marius.kjeldahl@gmail.com> wrote:
> I've read and re-read the module explanations from Per many times, but
> I still run into trouble, so I will ask here. My testing is done on
> Android, using gradle. If you do not know gradle, what you might need
> to know is that a project (by default) is laid out in a certain way.
> For instance for a kawa source file for the class
> net.kjeldahl.kawa.MyClass will exist in
> src/main/kawa/net/kjeldahl/kawa/MyClass.scm . Similarily, the output
> of the class files will go into the path
> build/classes/debug/net/kjeldahl/kawa/MyClass.class . To the best of
> my abilities I've also verified that the class files get put where
> they are supposed to be and that the stuff in them is correct (proper
> class names, using javap to check the contents).
>
> Anyway, I have my Android activity defined in it's own
> KawaActivity.scm file more or less like follows:
>
> (module-name net.kjeldahl.kawatest.app.KawaActivity)
> ...
> (require net.kjeldahl.kawatest.app.HelloKawa "HelloKawa.scm")
>
> (define-simple-class KawaActivity (Activity)
>   ((onCreate (savedInstanceState::Bundle)) (@Override)
>    (invoke-special Activity (this) 'onCreate savedInstanceState)
>    (define tv::TextView (TextView (this) text: "Kawa hello."))
>    (define my-view::View (LinearLayout (this)
>                                        orientation: LinearLayout:VERTICAL
>                                        view: tv))
>    ((this):setContentView my-view)
>    (define str (string-append "Retval: " (HelloKawa:hello)))
>    (tv:setText str)
>    ))
>
> The HelloKawa.scm source file is located in the same "namespace" and
> directory as the file above, and simply contains:
>
> (module-name net.kjeldahl.kawatest.app.HelloKawa)
>
> (define-simple-class HelloKawa ()
>   ((hello) allocation: 'static
>    "Hello from HelloKawa!"))
>
> ;; (define (hello)
> ;;    "Hello from Kawa!")
>
> The code shown above works just fine. What I am having trouble with is
> figuring out why certain things are needed and not.
>
> Question 1 - The line that does require HelloKawa; Unless I list the
> filename "HelloKawa.scm" as the second parameter, I will get a kawa
> compiler error; invalid specifier for 'require'. I have no idea why.
> I've experienced with setting the working dir prior to calling the
> kawa compiler, but it does not seem to matter much. It looks like kawa
> has it's own idea about the proper path for start searching for the
> source file for the module.
>
> Question 2 - When invoking (HelloKawa:hello), how come kawa knows
> about my HelloKawa class without the full class name? I haven't done
> any define-alias on it, so it's a bit unexpected.
>
> Question 3 - The file defining HelloKawa uses define-simple-class, but
> I've also tried it with a straight up define instead (you'll see that
> commented out in the source file above). If I do that, I get two
> errors from kawa; no known slot hello in java.lang.Object, and no
> declaration seen for HelloKawa. Based on what I've read, this second
> method of defining a module should work as long as we stay within the
> kawa domain, but I may have interpreted that wrong.
>
> And just to reiterate; I realize there are better ways to write this
> kind of code on Android. The trouble is there is a lot more code out
> there than Android, and I need to get comfortable with the mappings
> before I dare to try and do real stuff with this. If I'm still
> struggling at these basic things I can assure you when/if others try
> to follow they will have similar issues. So I'm hoping to have some
> answers ready!
>
> Thanks,
>
> Marius K.