manual:chapter3:lists

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Lists

Lists are ordered collections of objects of any type. Lists are entered as a sequence of objects enclosed in curly braces { and }. The syntax rules of each individual object still apply when they are within a list. Lists can contain any number of items, including none, therefore the empty list { } is valid and can be used. Items can be repeated within a list, and the order in which items are inserted is preserved unless the order is intentionally changed, for example using the SORT command.

Operating with Lists

In most cases, commands will accept a list instead of a single argument and will proceed according to the Parallel Processing with Lists section. For example, lists can be used to quickly apply the same operation to more than one value: 

2:                     { 1 2 3 }
1:                             1
……………………………………………………………………………………
+

will result in adding 1 to each element on the list: { 2 3 4 }.

There's operations that are exclusive to lists, for example the command ADD will concatenate two lists, or append 1 element at the end of the list. 

2:                     { 1 2 3 }
1:                             1
……………………………………………………………………………………
ADD

will result in { 1 2 3 1 } and 

2:                     { 1 2 3 }
1:                     { 4 5 6 }
……………………………………………………………………………………
ADD

will result in { 1 2 3 4 5 6 }

Other common commands that are specific for lists include (look into the command reference for details on specific commands). Operations with Lists

ADD

Synopsis

Concatenate lists and/or elements

Stack Diagram

Input Stack Output Stack
L1 L2 → Lconcat
L1 O → L1-upd
O L2 → L2-upd
O1 O2 → Lnew
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 ADD command concatenates lists or adds an element to a new list. It's not necessary that either the first or the second argument is a list: in this case ADD will create a new list containing both: in other words, single objects are treated as one-element lists.

Compatibility

ADD is not fully equivalent to its userRPL counterpart.

In particular:

  • in userRPL list concatenation is performed by the + operator, while ADD is the command to parallel process the addition;
  • in userRPL at least one of the arguments must be a list.

Usage

Input 

4:                                      
3:                                      
2:                           { 1 1 2 3 }
1:                            { 5 8 13 }
…………………………………………………………………………………………………………
ADD


Output 

4:                                      
3:                                      
2:                                      
1:                    { 1 1 2 3 5 8 13 }
…………………………………………………………………………………………………………

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

ADDROT

Synopsis

Add elements to a list, keeping only the last N elements

Stack Diagram

Input Stack Output Stack
Ldata Oitem Isize → Ldata-upd
Level 3 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 ADDROT command adds element to a list just like the command ADD does, but with a difference: if the list grows larger than Isize elements, the first one gets removed.

Compatibility

ADDROT is specific to newRPL and has no direct equivalent in userRPL.

Usage

Input 

4:                                      
3:                             { A B C }
2:                                     X
1:                                     3
…………………………………………………………………………………………………………
ADDROT


Output 

4:                                      
3:                                      
2:                                      
1:                             { B C X }
…………………………………………………………………………………………………………

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

DOLIST

Synopsis

Do a procedure with elements of lists

Stack Diagram

Input Stack Output Stack
L1 … Ln In Pexec → Lresults
L1 … Ln In Nexec → Lresults
Level n+2 … Level 3 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 DOLIST command EVALuates a specified program (or a variable which contains one) to lists of objects.

All lists must be the same length len. The program is executed len times: on the i-th iteration, In objects each taken from the i-th position in each list are entered on the stack in the same order as in their original lists, and the program Pexec is EVALuated. The results from each execution are left on the stack.

After the final iteration, any new results are combined into a single list: the UNMIX program presented here can help disentangling the results.

Compatibility

DOLIST is not fully equivalent to its userRPL counterpart.

In particular:

  • in userRPL the number of arguments can be omitted under certain conditions; in newRPL it must be always specified;
  • the program launched by DOLIST operates in a protected stack environment: no elements present on the stack before DOLIST is launched can be reached or altered.

Usage

Input 

5:                             { 1 2 3 }
4:                             { 4 5 6 }
3:                             { 7 8 9 }
2:                                     3
1:                               « + * »
…………………………………………………………………………………………………………
DOLIST


Output 

4:                                      
3:                                      
2:                                      
1:                          { 11 26 45 }
…………………………………………………………………………………………………………

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

ΔLIST

Synopsis

Return first differences of elements of a list

Stack Diagram

Input Stack Output Stack
Ldata → Ldiff
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 ΔLIST command returns the first differences of the elements in the list Ldata, i.e.: $$ data_2-data_1 \\ data_3-data_2 \\ data_4-data_3 \\ \ldots $$ The list must contain at least two elements, and the elements themselves must be suitable for mutual subtraction.

Compatibility

ΔLIST is fully equivalent to its userRPL counterpart.

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                  { 39 18 5 '2*X' 73 }
…………………………………………………………………………………………………………
ΔLIST


Output 

4:                                      
3:                                      
2:                                      
1:          { -21 -13 '2*X-5' '73-2*X' }
…………………………………………………………………………………………………………

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

DOSUBS

Synopsis

Do a procedure on a subset of a list

Stack Diagram

Input Stack Output Stack
Ldata In Pexec → Lresults
Ldata In Nexec → Lresults
Level 3 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 DOSUBS command EVALuates a specified program (or a variable which contains one) to groups of elements in a list.

The first iteration uses elements 1 through In from the list; the second iteration uses elements 2 through In + 1; and so on. In general, the m-th iteration uses the elements from the list corresponding to positions m through m + In – 1.

During an iteration, the position of the first element used in that iteration is available to the user using the local variable NSUB, and the number of groups of elements is available using the local variable ENDSUB.

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

Compatibility

DOSUBS is not fully equivalent to its userRPL counterpart.

In particular:

  • in userRPL the number of arguments can be omitted under certain conditions; in newRPL it must be always specified;
  • in userRPL NSUB and ENDSUBS are commands; in newRPL they are local variables;
  • the program launched by DOSUBS operates in a protected stack environment: no elements present on the stack before DOSUBS is launched can be reached or altered.

Usage

Input 

{ 1 2 3 4 5 }
2
« → a b
  « CASE
      'NSUB==1'
    THEN
      a
    END
      'NSUB==ENDSUB'
    THEN
      b
    END
      'a+b' EVAL
    END
  »
»
DOSUBS


Output 

4:                                      
3:                                      
2:                                      
1:                           { 1 5 7 5 }
…………………………………………………………………………………………………………

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

LIST→

Synopsis

Split a list into its elements

Stack Diagram

Input Stack Output Stack
L → On … O1 In
Level 1 → Level n+1 … Level 2 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 LIST→ command takes a list of In and returns each object to a separate level, and returns the total number of objects to stack level 1.

Compatibility

LIST→ is fully equivalent to its userRPL counterpart.

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                             { 1 3 5 }
…………………………………………………………………………………………………………
LIST→


Output 

4:                                     1
3:                                     3
2:                                     5
1:                                     3
…………………………………………………………………………………………………………

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

MAP

Synopsis

Do a procedure on each element of a list, recursively

Stack Diagram

Input Stack Output Stack
Ldata Pexec → Ldata-upd
Ldata Nexec → Ldata-upd
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 MAP command EVALuates a specified program (or a variable which contains one) to a list of objects or values. If one of the objects is a list, MAP will apply the program recursively to the items in the inner list.

MAP is nominally designed for Pexec (or Nexec) requiring one argument and returning one result.

Compatibility

MAP is fully equivalent to its userRPL counterpart.

Usage

Input 

4:                                      
3:                                      
2:                       { 1 2 { X Y } }
1:                               « 2 * »
…………………………………………………………………………………………………………
MAP


Output 

4:                                      
3:                                      
2:                                      
1:               { 2 4 { 'X*2' 'Y*2' } }
…………………………………………………………………………………………………………

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

ΠLIST

Synopsis

Return the product of all elements in a list

Stack Diagram

Input Stack Output Stack
Ldata → Oprod
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 ΠLIST command returns the product of all the elements in Ldata, i.e.: $$ \prod_{k=1}^{n}{data_{k}} $$ The list must not be empty and its elements must be suitable for mutual multiplication.

Compatibility

ΠLIST is not fully equivalent to its userRPL counterpart.

In particular:

  • in userRPL the list must contain at least two elements.

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                       { 5 'Z' '8+Y' }
…………………………………………………………………………………………………………
ΠLIST


Output 

4:                                      
3:                                      
2:                                      
1:                           '5*Z*(8+Y)'
…………………………………………………………………………………………………………

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

REVLIST

Synopsis

Reverse the order of elements in a list

Stack Diagram

Input Stack Output Stack
L → Lreversed
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 REVLIST command reverses the order of elements in a list. In addition with the SORT command it can be used to sort a list in descending order.

Compatibility

REVLIST is fully equivalent to its userRPL counterpart.

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                      { 5 1 4 3.1415 }
…………………………………………………………………………………………………………
REVLIST


Output 

4:                                      
3:                                      
2:                                      
1:                      { 3.1415 4 1 5 }
…………………………………………………………………………………………………………

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

SEQ

Synopsis

Assemble a list from results of sequential procedure

Stack Diagram

Input Stack Output Stack
Pexec Nindex Numstart Numend Numincr → Lresults
Aexec Nindex Numstart Numend Numincr → Lresults
Nexec Nindex Numstart Numend Numincr → Lresults
Level 5 Level 4 Level 3 Level 2 Level 1 → Level 1

Legend

Keyword type Command
Parallel list processing capabilities Group 7 Multiple argument, one result commands
Affected by flags None

Description

The SEQ command returns a list of results generated by repeatedly EVALuating a program, a symbolic object or an identifier using Nindex over the range Numstart to Numend, in increments of Numincr.

The action of SEQ for arbitrary inputs can be predicted exactly from this equivalent program: 

Numstart Numend FOR 'Nindex'
  Pexec EVAL
Numincr STEP
n → LIST

where n is the number of new objects left on the stack by the FOR … STEP loop. Notice that Nindex becomes a local variable regardless of its original type.

Compatibility

SEQ is not fully equivalent to its userRPL counterpart.

In particular:

  • the program launched by SEQ operates in a protected stack environment: no elements present on the stack before SEQ is launched can be reached or altered.

Usage

Input 

5:                                 'n^2'
4:                                   'n'
3:                                     1
2:                                     9
1:                                     2
…………………………………………………………………………………………………………
SEQ


Output 

4:                                      
3:                                      
2:                                      
1:            { '1' '9' '25' '49' '81' }
…………………………………………………………………………………………………………

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

SORT

Synopsis

Sort elements in a list

Stack Diagram

Input Stack Output Stack
L → Lsorted
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 SORT command uses a variant of the Insertion Sort (namely, the Binary Insertion Sort) to order the elements of a list in ascending order.

All the elements in the list must be of the same type; the comparison between elements is done by the CMP operator: if the TYPE of the objects within the list is not supported by CMP, no error is issued and the original list is left unmodified.

Compatibility

SORT is not fully equivalent to its userRPL counterpart.

In particular:

  • in newRPL strings are not supported (yet).

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                      { 5 1 4 3.1415 }
…………………………………………………………………………………………………………
SORT


Output 

4:                                      
3:                                      
2:                                      
1:                      { 1 3.1415 4 5 }
…………………………………………………………………………………………………………

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

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 not fully equivalent to its userRPL counterpart.

In particular:

  • the program launched by STREAM operates in a protected stack environment: no elements present on the stack before STREAM is launched can be reached or altered.

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

ΣLIST

Synopsis

Return the sum of all elements in a list

Stack Diagram

Input Stack Output Stack
Ldata → Osum
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 ΣLIST command returns the sum of all the elements in Ldata, i.e.: $$ \sum_{k=1}^{n}{data_{k}} $$ The list must not be empty and its elements must be suitable for mutual addition.

Compatibility

ΣLIST is not fully equivalent to its userRPL counterpart.

In particular:

  • in userRPL the list must contain at least two elements.

Usage

Input 

4:                                      
3:                                      
2:                                      
1:                       { 1 'X' '3*Y' }
…………………………………………………………………………………………………………
ΣLIST


Output 

4:                                      
3:                                      
2:                                      
1:                             '1+X+3*Y'
…………………………………………………………………………………………………………

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

→LIST

Synopsis

Assemble a list from its elements

Stack Diagram

Input Stack Output Stack
On … O1 In → L
Level n+1 … 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 →LIST command combines the first In elements on the stack above itself in a list.

Compatibility

→LIST is fully equivalent to its userRPL counterpart.

Usage

Input 

4:                                 '3/8'
3:                    "This is a string"
2:                              'SIN(X)'
1:                                     2
…………………………………………………………………………………………………………
→LIST


Output 

4:                                      
3:                                      
2:                                 '3/8'
1:       { "This is a string" 'SIN(X)' }
…………………………………………………………………………………………………………

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
  • →LIST: Creates a list from loose objects in the stack
  • LIST→: Split a list into individual objects in the stack
  • SORT: Sort the elements of a list

Operating with Lists

  • manual/chapter3/lists.1629062326.txt.gz
  • Last modified: 2021/08/15 14:18
  • by claudio