LlList2ListSlice

Function notes

The index of the first entry in the list is 0

The index of the first entry in a slice is 0

If start, end, or slice_index are negative they are indexed from end of list. -1 is last element in the list. -list_length is the 1st element of the list.

If slice_index is negative it is counted from the end of its stride regardless of whether or not the stride exceeds the end of the list. e.g: -1 is the last element in a stride.

If start > end the range from start to end is treated as an exclusion range.

Return value notes

Returns a list of the slice_index'th element of every stride in strided list whose index is a multiple of stride in the range start to end.

Examples

list mylist = [0,1,2,3,4,5,6];
list result_a = llList2ListSlice(mylist,0,-1,3,0); //start at first item in list, go to the end, return 1st slice of every stride of 3
//result_a == [0,3,6]

list result_b = llList2ListSlice(mylist,0,-1,3,1); //start at first item in list, go to the end, return 2nd slice of every stride of 3
//result_b == [1,4]

list result_c = llList2ListSlice(mylist,1,-1,3,1); //start at second item in list, go to the end, return 2nd slice of every stride of 3
//result_c == [2,5]

list result_d = llList2ListSlice(mylist,2,-1,3,-1); //start at third item in list, go to the end, return last slice of every stride of 3
//result_d == [4]

list result_e = llList2ListSlice(mylist,4,2,1,0); //4>2 so this is an exclusion. slice indices count from 0 and first element after exclusion. Return every element not in range with a stride of 1
//result_e == [0,1,2,4,5,6]

list menu = ["1", "one", "2", "two", "3", "three"];
default
{
    state_entry()
    {
        llListen(10, "", llGetOwner(), "");
    }
    touch_start(integer detected)
    {
        list buttons = llList2ListSlice(menu, 0, -1, 2, 0);
        llDialog(llDetectedKey(0), "choose a number", buttons, 10); //display the digits
    }
    listen(integer channel, string obj, key id, string message)
    {
        integer index = llListFindList(menu, [message]);
        if (index != -1)
        {
            list names = llList2ListSlice(menu, 0, -1, 2, 1);
            llOwnerSay("you chose " + llList2String(names, index/2) + " (" + message + ")");
        }
    }
}

Helper functions

StrideOfList - Starting from start and stopping before end exceeded it skips every stride-1 items. returns the slice_index element of the stride if its position is less than list length.

Notes

If the list is not modulo the stride, elements up to the length of the list will be returned in the final slice matching conditions. e.g. a list of 5 elements with a stride of 2 will return 3 elements for a 0,5 range on slice index 0 but only 2 if the slice_index is 1.

Shared wiki helpers

The original page also injects shared parameter notes, caveats or issue information through these helpers. Their conditional MediaWiki logic is not reproduced here; inspect the preserved helper source for additional material.

Template:LSL Function/negative index

Original shared helper source (conditional wiki logic is not evaluated)

{{LSL Injection Test}}<noinclude>
Format:
<nowiki>{{LSL Function/negative index|boolean|p1|p2|p3}}</nowiki><br/>
Exclude p1, p2, or p3 if not used.

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{{#vardefine:ni_mode|true}}
{{#vardefine:ni_nc|}}
{{#vardefine:ni_p1|number}}
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{{#vardefine:t|{{#ifeq:{{{1|{{#var:ni_mode}}}}}|true|{{#switch:{{#var:ni_c}}|3|2=LSL_Function/negative_index/range|1=LSL_Function/negative_index/single}}}}}}

{{{{#var:t}}|{{{2|{{#var:ni_p1}}}}}|{{{3|{{#var:ni_p2}}}}}|{{{4|{{#var:ni_p3}}}}}|noExclude={{{noExclude|}}}}}

{{#if:{{{noSpec|}}}||
{{#vardefine:spec|{{#var:spec}}
{{#if:{{#var:t}}|
{{{!}} {{Prettytable|style=float:left;}}
{{!}}-{{Hl2}}
! Index
! Positive
! Negative
{{!}}-
{{!}} First
{{!}} <code>0</code>
{{!}} <code>-{{{length|length}}}</code>
{{!}}-
{{!}} Last
{{!}} <code>{{{length|length}}} - 1</code>
{{!}} <code>-1</code>
{{!}}}
=== Indexes ===
<div style="display:table;"><div style="display:block;">
*Positive indexes count from the beginning, the first item being indexed as <code>0</code>, the last as <code>({{{length|length}}} - 1)</code>.
</div></div>
<div style="display:table;"><div style="display:block;">
*Negative indexes count from the far end, the first item being indexed as <code>-{{{length|length}}}</code>, the last as <code>-1</code>. 
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}}
}}
}}

{{#vardefine:also_articles|{{#var:also_articles}}
{{#if:{{#var:t}}|{{LSL_DefineRow||{{LSLGC|Negative_Index{{#var:lang}}|Negative Index}}|}}}}}}

{{#vardefine:header_footnote|{{#var:header_footnote}}{{PBR}}
{{#vardefineecho:ni_ps|{{#switch:{{#var:ni_c}}
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  |1={{LSLP|{{{2}}}}}
  |2={{LSLP|{{{2}}}}} & {{LSLP|{{{3}}}}}
  |3={{LSLP|{{{2}}}}}, {{LSLP|{{{3}}}}} & {{LSLP|{{{4}}}}}
 }}}} {{#if:{{#var:t}}| support{{#ifexpr:{{#var:ni_c}}>1||s}}| ''do{{#ifexpr:{{#var:ni_c}}>1||es}} not'' support }} {{LSLGC|Negative_Index{{#var:lang}}|negative indexes}}.{{PBR}}
}}

{{#vardefine:footer|{{#var:footer}}
{{#if:{{#var:t}}|{{#ifeq:{{NAMESPACE}}|Template||{{#if:{{#var:self}}{{{self|}}}{{#pos:{{#var:moded}}|r}}{{#pos:{{#var:moded}}|u}}||{{LSLC|Negative Index{{#var:lang}}}}}}}}|
{{#if:{{#var:self}}{{{self|}}}{{#pos:{{#var:moded}}|r}}{{#pos:{{#var:moded}}|u}}||{{LSLC|Positive_Index_Only{{#var:lang}}}}}}
}}}}

{{#vardefine:caveats|{{#var:caveats}}
{{#if:{{{nc|{{#var:ni_nc}}}}}||
* If {{#switch:{{#var:ni_c}}
 |3=either {{LSLP|{{{2}}}}}, {{LSLP|{{{3}}}}} or {{LSLP|{{{4}}}}} are
 |2=either {{LSLP|{{{2}}}}} or {{LSLP|{{{3}}}}} are
 |1={{LSLP|{{{2}}}}} is}} out of bounds {{#if:{{{oob-return|}}}|this function returns {{{oob-return|}}} and}} the script continues to execute without an error message.
{{#if:{{#var:t}}|{{#ifexpr:{{#var:ni_c}}>1|{{#if:{{{noExclude|}}}|* {{LSLP|{{{2}}}}} & {{LSLP|{{{3}}}}} will not form an [[#exclusion_range|exclusion range]] when {{LSLP|{{{2}}}}} is past {{LSLP|{{{3}}}}} (Approximately: {{LSLP|{{{2}}}}} > {{LSLP|{{{3}}}}}), instead it will act as if {{LSLP|{{{2}}}}} was zero & {{LSLP|{{{3}}}}} was -1.|* {{LSLP|{{{2}}}}} & {{LSLP|{{{3}}}}} will form an [[#exclusion_range|exclusion range]] when {{LSLP|{{{2}}}}} is past {{LSLP|{{{3}}}}} (Approximately: {{LSLP|{{{2}}}}} > {{LSLP|{{{3}}}}}). }}}}}}
}}}}

}}<noinclude>
==Debugging==
{| {{Prettytable}}
|-{{Hl2}}
! #var
! value
|-
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|-
{{VarPair|notes}}
|-
{{VarPair|constants_nb}}
|-
{{VarPairTable|also_articles}}
|-
{{VarPair|footer}}
|}
</noinclude>

Template:LSL Function/stride

Original shared helper source (conditional wiki logic is not evaluated)

{{LSL Injection Test}}{{#if:

{{#vardefine:header_footnote|This function supports [[List#Strided_lists|Strided Lists]].}}

{{#vardefine:p_{{{1|none}}}_hover|number of entries per stride, if less than 1 it is assumed to be 1}}
{{#vardefine:p_{{{1|none}}}_desc|number of entries per stride, if less than 1 it is assumed to be 1}}

}}<noinclude>
{| {{Prettytable}}
|- {{Hl2}}
! #var
! value
|-
{{VarPair|p_{{{1|none}}}_desc}}
|-
{{VarPair|p_{{{1|none}}}_hover}}
|-
{{VarPair|header_footnote}}
|}
</noinclude>