Pair

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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, written ,⍥⊂ using Over[1]. It was introduced in Extended Dyalog APL, and then adopted into dzaima/APL. It was added to BQN with the glyph in 2021.

Common usage

Its plain usage is in pairing up two parallel values:

Try it online!

      6 7 8(+⍮-)3
┌───────┬─────┐
│9 10 11│3 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

External links

Documentation

See also

References

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