On Mon, Nov 24, 2008 at 2:03 PM, Peter Hercek
Simon Marlow wrote:
Claus Reinke wrote:
Perhaps someone could help me to understand how the debugger is supposed to be used, as I tend to have this problem, too:
- when I'm at a break point, I'd really like to see the current scope or, if that is too expensive, the next enclosing scope, in full (not only would that tell me what instantiation of my code I'm in, it would also seem necessary if I want to reconstruct what the current expression is)
I don't understand what you mean here - surely in order to "reconstruct what the current expression is" you only need to know the values of the free variables of that expression? Also I don't understand what you mean by the "next enclosing scope". Could you give an example?
Maybe what Claus means is that he would like to see the dynamic stack and be able to traverse it and at each location in the dynamic stack he could investigate the free variables in the expression (corresponding to the dynamic stack slot). I actually considered this as a feature request but I decided that I would like to have this implemented sooner: http://hackage.haskell.org/trac/ghc/ticket/2737
As long as you start with :trace, you can see the dynamic stack with :history, and traverse it with :back. At any point in the stack the free variables are available, or so I believe. What is the missing feature you would like to request in this case?