Re: kawa binary snapshot

[Jamison Hope <jrh@theptrgroup.com>]

On Jun 6, 2016, at 12:03 PM, Per Bothner <per@bothner.com> wrote:

> I'm switching to a new "more complete" style of binary releases for Kawa.
> Please check out:
>    ftp://ftp.gnu.org/pub/gnu/kawa/kawa-2.1.9-20160605.zip
> 
> Later, we could perhaps set up automatically-generated binary snapshots.
> 
> This bundles not only the kawa .jar file, but also a shell script
> (bin/kawa) or Windows batch file (bin/kawa.bat), along with version 3
> of the jline input library.  This should be fairly portable.
> The jline input editing doesn't seem to work on Windows (I need to
> research how to fix this), but it works fine on Fedora and probably
> most GNU/Linux distributions. Reports on how it works on *BSD and MacOS
> would be helpful.

It seems to work fine on Mac OS X, as long as I run under Java 8.
I get an UnsupportedClassVersionError if I try to use Java 7.

(Also, the path to servlet.jar in the script is not very portable, but
this doesn't affect ordinary non-server usage.)

> Using jline3 has a number of advantages:  In contrast to GNU readline,
> it doesn't require compiling a C program, which makes it easier to
> distribute binaries.  It supports command completion.   (Well, so does GNU
> readline, but it's more complicated to write, especially if we want to
> avoid subjecting Kawa to the GPL.)

I usually just use rlwrap, as in

alias kawa='rlwrap -q\" java kawa.repl'

which avoids the compilation / linking-to-readline issue.

> The multi-line input editing is neat: While writing a continuation line,
> you can go back and edit an earlier line in the multi-line command.
> A continuation line is when you hit enter when more input is required
> (such as inside parenthesis), or if you explicitly type Esc Enter or Ctrl-Q Ctrl-J.
> Multi-line commands are stored as a single entry in the history.

Yeah that is neat, and is something that rlwrap can't match (since it
just dumbly wraps I/O to java without knowing anything of parenthesis
matching).

> More REPL improvements are planned.

Are the prompt colors going to be customizable?  I usually do
white-on-black, so the JLine prompt ends up being white on light green,
which is hard to read.


--
Jamison Hope
The PTR Group
www.theptrgroup.com