On Mon, Dec 03, 2001 at 08:31:00AM -0800, Terrence Brannon wrote: > Also, I thought Parrot was not "stack-based" If that is the case > then why does Overview.pod say this: > > "Registers will be stored in register frames, which can be pushed and > popped onto the register stack. For instance, a subroutine or a block > might need its own register frame."
This describes the operation of a register based architecture. That is, the current state of the registers (register frame) are pushed and popped as necessary (typically upon function invocation). A stack architecture does not have general purpose registers that are individually addressable. The Forth "VM" (implemented in silicon by i-forget-whom) contains a stack of ~16 data and ~16 code operands, and no registers. There is no way to address the individual contents of the stacks, save the topmost element (or two) of the stack. Z.
