I took a look at the code, and it looks like the vast majority of the change is the addition of 'readfns* and writefns*, which is pretty awesome in and of itself. You could definitely use that like reader macros for embedding templates for other language code in Jarc.
I couldn't help but notice that you fixed no more than one thing from (http://arclanguage.org/item?id=12269), the (string '|.|) issue, but no worries. :-p
I've been away from the forum (trying to get my startup launched). I'll look into the bug reports in http://arclanguage.org/item?id=12269 this week. Thanks for the bug reports, as always.
I've changed the default behavior for printing Java types that don't have a fn in writefns* -- Jarc now prints them as
#package.class(hashCode)
It was getting annoying getting the missing writefns* messages. You can still define your own, but it doesn't pester you to do so anymore.
I'm working on a Rainbow compatibility module so that Jarc and Rainbow can share modules that call out to Java classes (like Swing and GAE datastore).
