Re: Questions for Geiser

[Per Bothner <per at bothner dot com>]

On 04/06/2015 10:23 PM, Dan Leslie wrote:
> I began efforts to add support for Kawa to Geiser while on my way home
> from work. A bit of forewarning: due to day job and family constraints
> most of my FOSS efforts are in those moments where I can find some time
> on the train to hack.
>
> Anyhow, I've several questions I'd like to raise:
>
> 1. Is there a way to define new top level methods? Or rather, are
> top level methods a thing in Kawa? Not that this is a blocker, I'm
> simply curious.

Not sure what you mean.  You can certainly define top-level functions.
Or rather module-level functions - and those are implicitly added to the
top-level environment when you load a module.

(I use "module" similarly to R7RS uses the term library.)

A named top-level function is compiled a primary method that implements it,
possibly some helper methods (that I'll ignore for now), and a field
that holds the function as a value.

> 2. What reflection and completion utilities are available, if any? I
> noticed that SchemeWay effectively overrides relevant binding routines
> in order to keep a dictionary for reflection; that doesn't seem like
> an approach that would be reasonable to maintain or one that I'd like to mimic.

The Kawa compiler and run-time do quite a bit of reflection.  For example you can
import a plain-old-Java-class with static fields (using the R7RS import
command), and the static fields become bindings in the importing scope.
When you import a module/library, Kawa basically resolves the module to a Java class,
and then just looks at the public fields of the class, figuring out the bindings
from those.

> 3. Geiser is very module-centric, and supports behaviours wherein its
> aware of the R7RS-library or implementation-specific module in which a
> symbol lays and will rebind it appropriately when a relevant region or
> other is evaluated. What tools does Kawa provide for, say, declaring the
> library/module/namespace in which a block is to be evaluated?

Kawa does support R7RS eval and load, where you can specify an environment to use,
in the form of R7RS environment specifiers.  See:

http://www.gnu.org/software/kawa/Eval-and-Environments.html
 
> I hope that wasn't to abrupt of me. I'm rather curious about this scheme
> of which I haven't a whole lot of experience. :)

Kawa is also very module-centric.  I suggest reading this:

http://www.gnu.org/software/kawa/Module-classes.html
http://www.gnu.org/software/kawa/Importing.html
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/