/ c-f-stack /
The ANS Forth standard says that it may not physically exist:
> 220.127.116.11 Control-flow stack
> If it does exist, it may be, but
> need not be, implemented using the data stack. The format of
> the control-flow stack is implementation defined.
This means that the control-flow stack may exist
only logically rather than both logically and physically.
> Since the control-flow stack may be implemented
> using the data stack, items placed on the data stack
> are unavailable to a program after items are placed
> on the control-flow stack and remain unavailable until
> the control-flow stack items are removed.
Equally placing new items onto the data stack blocks
access to the control-flow stack items.
A standard program cannot assume that the items left on the data
stack are not modified, moved or removed while there are
control-flow stack elements above them.
See also: ../colon-sys
generated Wed Jul 23 02:53:41 2003mlg