Re: How to create interactive mode for Java Swing application using Lua Java?

[Sam Roberts <sroberts@...>]

On Tue, Oct 24, 2006 at 10:43:11PM +0100, Jonas Bengtsson wrote:
> I think it was mainly a misunderstanding from my side. I thought the 
> interactive mode works like irb for Ruby or Python, like:
> 
> > 1 + 4
> 5
> > foo()
> "hello world"
> 
> But now I know it doesn't so I don't have to recreate it in my Swing 
> shell. Too bad Lua doesn't have implicit returns :-)

It does have the "=" shortcut:

	> = 1 + 4
	5
	> = (function() return"hello world" end)()
	hello world

= is just replaced with "return "

Also, a trick I learned from somewhere in the source and use in my
interactive consoles - I prepend "return " to any code before loading
it. If it fails to compile because of a syntax error, I try again
without the return.

This means that anything typed at the prompt that is an expression, like

> foo()

will leave it's return values on the stack. Then after the pcall you can
walk the stack and print any values you find on it. This makes it a bit
more irb-like.