From: Clifford Heath <clifford.heath@...>
Date: 2011-05-27T09:16:30+09:00
Subject: [ruby-core:36500] Re: Error reporting, backtraces and the debugger

On 26/05/2011, at 10:34 AM, Asher wrote:
> I've implemented an objective backtrace and some other tools in  
> Sender: https://rubygems.org/gems/sender

The textual backtrace already had the method and object name.
Sender adds the object in each frame (nice!), but seems to
add little else, other than the convenience methods...? Have I
misunderstood?

Also, when I talk about the frame, I want the binding context
for parameters and local variables, so you can explore and
enumerate those. You might be curious to read some interesting
stuff I explored in this gist: <https://gist.github.com/732930>.

It enables interesting "foreign" DSLs to be integrated into Ruby
in a way that allows interaction with the local variables of the
*caller*, so for example you can do stuff like:

def test
   param = "foo"
   result = nil
   foreign_language{%q{
	-- Some text in a foreign DSL which can read and modify caller's vars
       result = param+"bar"
   }}
   p result
end
test
=> "foobar"

Yes, really. Read that again! Interesting stuff. It uses the binding
of the passed-in block as an access point to seeing the variables.

So that's what got be thinking that the debugger should be able to
use the binding in a backtrace to see and modify local variables
and parameters in the call stack.

Clifford Heath.