Pair: Difference between revisions

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(Reference for catenate over enclose in 1981)
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{{Built-in|Pair|⍮}} or '''Juxtapose''' is a [[primitive function]] equivalent to the [[dfn]] <source lang=apl inline>{⍺←,⊂ ⋄ ⍺ ⍵}</source> which aids in constructing nested arrays during [[tacit programming]] where [[stranding]] by juxtaposition is not available. It is also equivalent to the [[catenate|catenation]] of the [[enclose]]d arguments; <source lang=apl inline>,⍥⊂</source> using the [[Over]] [[operator]]<ref>[https://www.jsoftware.com/papers/satn41.htm "Composition and Enclosure"] §
{{Built-in|Pair|⍮}} or '''Juxtapose''' is a [[primitive function]] equivalent to the [[dfn]] <syntaxhighlight lang=apl inline>{⍺←,⊂ ⋄ ⍺ ⍵}</syntaxhighlight> which aids in constructing nested arrays during [[tacit programming]] where [[stranding]] by juxtaposition is not available. It is also equivalent to the [[catenate|catenation]] of the [[enclose]]d arguments; <syntaxhighlight lang=apl inline>,⍥⊂</syntaxhighlight> using the [[Over]] [[operator]]<ref>[https://www.jsoftware.com/papers/satn41.htm "Composition and Enclosure"] §
Composition Operators. SATN-41, 1981-06-20.</ref> or <source lang=apl inline>,⍨∘⊂⍨∘⊂</source> using only the traditional operators [[Commute]] and [[Compose]]. It was introduced in [[Extended Dyalog APL]], and then adopted into [[dzaima/APL]].
Composition Operators. SATN-41, 1981-06-20.</ref> or <syntaxhighlight lang=apl inline>,⍨∘⊂⍨∘⊂</syntaxhighlight> using only the traditional operators [[Commute]] and [[Compose]]. It was introduced in [[Extended Dyalog APL]], and then adopted into [[dzaima/APL]].


== Common usage ==
== Common usage ==
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[https://tio.run/##SyzI0U2pSszMTfz//1Hf1EdtE8wUzBUsNLQf9a7T1TT@/x8A Try it online!]
[https://tio.run/##SyzI0U2pSszMTfz//1Hf1EdtE8wUzBUsNLQf9a7T1TT@/x8A Try it online!]
<source lang=apl>
<syntaxhighlight lang=apl>
       6 7 8(+⍮-)3
       6 7 8(+⍮-)3
┌───────┬─────┐
┌───────┬─────┐
│9 10 11│3 4 5│
│9 10 11│3 4 5│
└───────┴─────┘
└───────┴─────┘
</source>
</syntaxhighlight>
{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}}
{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}}


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[https://tio.run/##SyzI0U2pSszMTfz//1Hf1EdtE8wUzBUsNLQftU181LvkUe86XU3j//8B Try it online!]
[https://tio.run/##SyzI0U2pSszMTfz//1Hf1EdtE8wUzBUsNLQftU181LvkUe86XU3j//8B Try it online!]
<source lang=apl>
<syntaxhighlight lang=apl>
       6 7 8(+↑⍤⍮-)3
       6 7 8(+↑⍤⍮-)3
9 10 11
9 10 11
3  4  5
3  4  5
</source>
</syntaxhighlight>
{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}}
{{Works in|[[dzaima/APL]], [[Extended Dyalog APL]]}}



Latest revision as of 22:24, 10 September 2022

Pair () or Juxtapose is a primitive function equivalent to the dfn {,⊂ } which aids in constructing nested arrays during tacit programming where stranding by juxtaposition is not available. It is also equivalent to the catenation of the enclosed arguments; , using the Over operator[1] or ,⍨∘⍨∘ using only the traditional operators Commute and Compose. It was introduced in Extended Dyalog APL, and then adopted into dzaima/APL.

Common usage

Its plain usage is in pairing up two parallel values:

Try it online!

      6 7 8(+⍮-)3
┌───────┬─────┐
9 10 113 4 5
└───────┴─────┘

It can also be combined with Mix to increase rank rather than depth:

Try it online!

      6 7 8(+↑⍮-)3
9 10 11
3  4  5

See also

References

  1. "Composition and Enclosure" § Composition Operators. SATN-41, 1981-06-20.
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