[armedbear-devel] asdf encodings and abcl

[Mark Evenson]

On Apr 9, 2012, at 03:21 , Faré wrote:

> Dear ABCL developers,
> 
> I'm currently adding source file encoding support to ASDF.
> It will hopefully be part of ASDF 2.21, though the plan is that
> anything but :utf-8 and :default requires an extension :asdf-encodings.
> 
> I didn't find any way with ABCL to detect the list of external formats,
> or to determine is a given keyword is an acceptable name for an external format.
> 
> How do I do that?

After a quick check, I don't think we define an interface.  Nor
could I find something in SBCL to copy.  Do you have a reference to an API we can
implement?

Essentially we thunk through to the [JVM Charset implementation][1],
is which each named charset is used as its natural keyword form
(i.e. the JVM charset ISO-8859-1 is specified by passing the :iso-8859-1
keyword).  

As an intermediate solution, 

  (require 'abcl-contrib) 
  (require 'jss)
  (jss:hashmap-to-hashtable (#"availableCharsets" 'java.nio.charset.Charset))

will return a hashtable whose keys will be the allowable names for external formats.

"Intermediate" because I would like to keep ASDF independent of the
abcl-contrib mechanism, as ASDF is a requirement of ABCL-CONTRIB,
so I'd rather that we agree on an API, and I'll implement this with
the Java FFI primitives that JSS is based upon.


[1]: http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html


--
"A screaming comes across the sky.  It has happened before, but there is nothing to compare to it now."