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{{Built-in|Select|⊇}} (jokingly referred to as ''Sane Indexing'') is a [[primitive function]] that allows selecting multiple [[major cell]]s using indices of the cells. It is equivalent to <source lang=apl inline>⌷⍨∘⊂⍨</source> and <source lang=apl inline>⌷⍤0 ∞</source>, only providing a neater notation for such a fundamental concept. It was introduced in [[Extended Dyalog APL]], and then adopted into [[dzaima/APL]] and [[KAP]]. | {{Built-in|Select|⊇}} ([[humour|jokingly]] referred to as ''Sane Indexing'') is a [[primitive function]] that allows selecting multiple [[major cell]]s using indices of the cells. It is equivalent to <source lang=apl inline>⌷⍨∘⊂⍨</source> and <source lang=apl inline>⌷⍤0 ∞</source>, only providing a neater notation for such a fundamental concept. It was introduced in [[Extended Dyalog APL]], and then adopted into [[dzaima/APL]] and [[KAP]]. | ||
== Common usage == | == Common usage == | ||
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</source>{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}} | </source>{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}} | ||
== Potential extension == | == Potential extension == | ||
Select can be defined as <source lang=apl inline>⌷⍨∘⊃⍨⍤0 ∞</source> thus allowing both the above usage and "scatter point indexing": | Select can be defined as <source lang=apl inline>⌷⍨∘⊃⍨⍤0 ∞</source> thus allowing both the above usage and "scatter point indexing":<ref>[[Richard Park]]. [https://dyalog.tv/Webinar/?v=AgYDvSF2FfU Selecting from Arrays]. [[Dyalog Webinar]]. 16 Apr 2020. (Presented in the form <source lang=apl inline>((⊃⊣)⌷⊢)⍤0 99</source>.)</ref> | ||
<source lang=apl> | <source lang=apl> | ||
1 4 3 ⊇ 4 4⍴⎕A | 1 4 3 ⊇ 4 4⍴⎕A | ||
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* [[Bracket indexing]] | * [[Bracket indexing]] | ||
* [[Pick]] | * [[Pick]] | ||
== References == | |||
<references/> | |||
{{APL built-ins}}[[Category:Primitive functions]] | {{APL built-ins}}[[Category:Primitive functions]] |