manual:chapter6:stack:cmd_stkpop

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Description


Pop a snapshot from the top of the “stack of stacks” onto the current stack. Current stack contents will be overwritten and lost, and the snapshot will be removed from the “stack of stacks”.

Stack Diagram


Input Stack Output Stack
O…
N Levels M Levels

Legend

Support for inclusion in symbolic expressions
Support for parallel list processing
Affected by flags

Compatibility


This command is new in newRPL, does not exist in userRPL.

Usage


The following program:

« 123
  456
  789
  STKPUSH
  CLEAR
  999
  STKPOP
»

the numbers 123, 456, 789 will appear on the stack, while the 999 is lost when STKPOP restores the snapshot.

Related Commands

Stack manipulation 27 5 NEW

Command Short Description
CLEAR Remove all objects from the stack
DEPTH Get the current stack depth
DROP Remove an object from the stack
DROP2 Remove two objects form the stack
DROPN Remove N objects from the stack
DUP Duplicate an object on the stack
DUP2 Duplicate two objects on the stack
DUPDUP Duplicate the same object twice on the stack
DUPN Duplicate a group of N objects
NDUPN Replicate one object N times and return N
NIP Remove object at level 2 on the stack
OVER Duplicate object at level 2 on the stack
PICK Duplicate object at position N on the stack
PICK3 Duplicate object at level 3 on the stack
ROLL Move object at level N to level 1
ROLLD Move object from level 1 to level N
ROT Move object from level 3 to level 1
SWAP Exchange objects in levels 1 and 2
UNPICK Move object from level 1 to level N.
UNROT Move object from level 1 to level 3
IFT Evaluate objects on the stack conditionally
IFTE Evaluate objects on the stack conditionally
STKPUSH Push a snapshot of the current stack on the undo stack NEW
STKPOP Pop a stack snapshot from the undo stack NEW
STKDROP Drop a snapshot from the undo stack NEW
STKPICK Copy snapshot in level N to the current stack NEW
STKDEPTH Get the depth of the undo stack NEW
  • manual/chapter6/stack/cmd_stkpop.1570636075.txt.gz
  • Last modified: 2019/10/09 08:47
  • by claudio