Trace on Variable assignment

[Torbjorn Tornkvist]

> I had more in mind though being able to set up traces (or conditional
> watchpoints if you like) in a running system without needing to change the
> code.

What about a guard: watch/1 which could be combined with 
the trace bif ? 
Example:

foo(X,Y) when watch(Y) ->
  case bar(X) of
    {Z,W} when watch(W) ->
       ....
  end.

When running trace on the process executing foo we 
could then get info about Y and W .

Just a thought... /Tobbe