Enlist: Difference between revisions

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{{Built-in|Enlist|∊}} is a [[primitive function]] which returns a [[simple]] [[vector]] of all simple [[scalar]] values in a possibly [[nested array]]. Enlist differs from [[Ravel]] in that Enlist flattens over all layers of nesting, while Ravel flattens only the outermost layer. Enlist shares its [[glyph]] <source lang=apl inline>∊</syntaxhighlight> with the dyadic function [[Membership]].
{{Built-in|Enlist|∊}} is a [[primitive function]] which returns a [[simple]] [[vector]] of all simple [[scalar]] values in a possibly [[nested array]]. Enlist differs from [[Ravel]] in that Enlist flattens over all layers of nesting, while Ravel flattens only the outermost layer. Enlist shares its [[glyph]] <syntaxhighlight lang=apl inline>∊</syntaxhighlight> with the dyadic function [[Membership]].


== Examples ==
== Examples ==
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Enlist is equivalent to a [[wikipedia:depth-first search|depth-first search]] collecting all simple scalars, where each layer (which in turn can be of any rank) is traversed in [[ravel order]].
Enlist is equivalent to a [[wikipedia:depth-first search|depth-first search]] collecting all simple scalars, where each layer (which in turn can be of any rank) is traversed in [[ravel order]].


<source lang=apl>
<syntaxhighlight lang=apl>
       ⎕←MAT←2 2⍴'MISS' 'IS' 'SIP' 'PI'
       ⎕←MAT←2 2⍴'MISS' 'IS' 'SIP' 'PI'
┌────┬──┐
┌────┬──┐
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Enlist acts like [[Ravel]] for simple arrays. This includes simple scalars, where the result is a [[singleton]] vector.
Enlist acts like [[Ravel]] for simple arrays. This includes simple scalars, where the result is a [[singleton]] vector.


<source lang=apl>
<syntaxhighlight lang=apl>
       ⎕←mat←4 4⍴⍳16
       ⎕←mat←4 4⍴⍳16
  1  2  3  4
  1  2  3  4

Revision as of 22:04, 10 September 2022

Enlist () is a primitive function which returns a simple vector of all simple scalar values in a possibly nested array. Enlist differs from Ravel in that Enlist flattens over all layers of nesting, while Ravel flattens only the outermost layer. Enlist shares its glyph with the dyadic function Membership.

Examples

Enlist is equivalent to a depth-first search collecting all simple scalars, where each layer (which in turn can be of any rank) is traversed in ravel order.

      ⎕←MAT←2 2⍴'MISS' 'IS' 'SIP' 'PI'
┌────┬──┐
│MISS│IS│
├────┼──┤
│SIP │PI│
└────┴──┘
      ∊MAT
MISSISSIPPI

      ⎕←M←1 (2 2⍴2 3 4 5) (6(7 8))
┌─┬───┬───────┐
│1│2 3│┌─┬───┐│
│ │4 5││6│7 8││
│ │   │└─┴───┘│
└─┴───┴───────┘
      ∊M
1 2 3 4 5 6 7 8

Enlist acts like Ravel for simple arrays. This includes simple scalars, where the result is a singleton vector.

      ⎕←mat←4 4⍴⍳16
 1  2  3  4
 5  6  7  8
 9 10 11 12
13 14 15 16
      (,mat)≡∊mat
1

      ∊3
3
      3 ≡ ∊3                  ⍝ Not the same
0
      ⍴∊3                     ⍝ It's now a vector
1

External links

Lessons

Documentation


APL built-ins [edit]
Primitives (Timeline) Functions
Scalar
Monadic ConjugateNegateSignumReciprocalMagnitudeExponentialNatural LogarithmFloorCeilingFactorialNotPi TimesRollTypeImaginarySquare Root
Dyadic AddSubtractTimesDivideResiduePowerLogarithmMinimumMaximumBinomialComparison functionsBoolean functions (And, Or, Nand, Nor) ∙ GCDLCMCircularComplexRoot
Non-Scalar
Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
Selection FirstPickTakeDropUniqueIdentityStopSelectReplicateExpandSet functions (IntersectionUnionWithout) ∙ Bracket indexingIndexCartesian ProductSort
Selector Index generatorGradeIndex OfInterval IndexIndicesDealPrefix and suffix vectors
Computational MatchNot MatchMembershipFindNub SieveEncodeDecodeMatrix InverseMatrix DivideFormatExecuteMaterialiseRange
Operators Monadic EachCommuteConstantReplicateExpandReduceWindowed ReduceScanOuter ProductKeyI-BeamSpawnFunction axis
Dyadic BindCompositions (Compose, Reverse Compose, Beside, Withe, Atop, Over) ∙ Inner ProductDeterminantPowerAtUnderRankDepthVariantStencilCutDirect definition (operator)
Quad names Index originComparison toleranceMigration levelAtomic vector