Officially support JRuby

[headius]

JRuby appears to be able to use rb-readline just fine these days.

$ rake test
/Users/headius/projects/jruby/bin/jruby -w -I"lib:test" -I"/Users/headius/projects/jruby/lib/ruby/gems/shared/gems/rake-12.2.1/lib" "/Users/headius/projects/jruby/lib/ruby/gems/shared/gems/rake-12.2.1/lib/rake/rake_test_loader.rb" "test/test_completion.rb" "test/test_filename_completion_proc.rb" "test/test_history.rb" "test/test_rbreadline.rb" "test/test_readline.rb" 
Run options: --seed 4979

# Running:

.................................................

Finished in 0.303875s, 161.2508 runs/s, 309.3382 assertions/s.
49 runs, 94 assertions, 0 failures, 0 errors, 0 skips

I have started recommending it to folks having problems with our built-in mostly-Java readline, such as here: jruby/jruby#1372

We are also considering shipping rb-readline as our standard readline library, for platforms where it will work (e.g. Windows will still use the mostly-Java readline we currently ship).

Anything we should watch out for? Any reason why rb-readline couldn't officially support JRuby at this point?

[MSP-Greg]

@headius @ConnorAtherton

We are also considering shipping rb-readline as our standard readline library

By chance, have you done so?

Also, long story, but a popular gem is using my fork of this for Appveyor CI testing due to issues with the current release.

I was reminded of all of this when I ran some 'build info' code with warnings on, and upon loading readline, there were several warnings...

Connor - Would you consider a transfer of this repo to another user? Maybe OneClick or JRuby?

Thanks, Greg

[Spakman]

@headius Hello! I've had a multi-year long hiatus from maintaining rb-readline and haven't been keeping up with the issues at all. Do you still plan ship rb-readline with JRuby?

I'm afraid my knowledge of JRuby is fairly minimal (and out of date) and I'm unsure of what sort of sneaky issues you might encounter, but I'm struggling to think of anything that might trip you up too badly at the moment. I'm definitely keen for us to support JRuby if it's going to be useful to our friends over on the JVM!