Interface Summary
StackListener A StackListener is informed when SimpleStackSimulator updates its simulated stack.

Class Summary
DebugStackListener Prints stuff about some of the actions encountered -- implementation not complete or consistent.
FilterStackListener Implements all methods of StackListener as pass-throughs.
NullStackListener Implements all methods of StackListener as no-ops
Operand Data on which Actions operate, either arguments poped of the emulated stack, or results pushed back onto it.
SimpleStackSimulator Builds a picture of the actionscript stack layout as each instruction is executed, driving an implementation of StackListener.
StackInfo A stack of Operand objects.
VariableProcessor FIXME: this is just a toy implementation, taking no account of scoping rules