manual:chapter6:lists:cmd_stream

Synopsis


Assemble a list from results of sequential procedure

Stack Diagram


Input Stack Output Stack
Ldata Pexec Oresult
Ldata Nexec Oresult
Level 2 Level 1 Level 1

Legend

Keyword type Command
Parallel list processing capabilities Group 2 Commands that must use DOLIST to parallel process
Affected by flags None

Description


The STREAM command moves the first two elements from Ldata onto the stack, EVALuating a program or an identifier. Then moves the next element (if any) onto the stack, and EVALuates Pexec (or Nexec) again using the previous result and the new element. Repeats this until Ldata is exhausted, and returns the final result.

STREAM is nominally designed for Pexec (or Nexec) requiring two arguments and returning one result.

Compatibility


STREAM is fully equivalent to its userRPL counterpart.

Usage


Input

4:                                      
3:                                      
2:                   { "A" "B" "C" "D" }
1:                            « SWAP + »
…………………………………………………………………………………………………………
STREAM                                  


Output

4:                                      
3:                                      
2:                                      
1:                                "DCBA"
…………………………………………………………………………………………………………
                                        

Related Commands


Operations with Lists 15 2 NEW

Command Short Description
→LIST Assemble a list from its elements
LIST→ Split a list into its elements
DOLIST Do a procedure with elements of lists CHANGED
DOSUBS Do a procedure on a subset of a list CHANGED
MAP Do a procedure on each element of a list, recursively
MAPLIST→ Do a procedure on each element recursively, return individual elements NEW
STREAM Do a procedure on consecutive elements of a list
ΔLIST First differences on the elements of a list
ΣLIST Sum of all elements in a list CHANGED
ΠLIST Product of all elements in a list CHANGED
ADD Concatenate lists and/or elements CHANGED
SORT Sort elements in a list
REVLIST Reverse the order of elements in a list
ADDROT Add elements to a list, keep only the last N elements NEW
SEQ Assemble a list from results of sequential procedure
  • manual/chapter6/lists/cmd_stream.txt
  • Last modified: 2021/09/23 14:43
  • by jojo1973