Partitioned Enclose: Difference between revisions

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== Basic functionality ==
== Basic functionality ==
In the simplest case, and on a vector right argument, the corresponding element in the left argument indicates where '''divisions''' begin:
In the simplest case, and on a vector right argument, the corresponding element in the left argument indicates where '''divisions''' begin:
<source lang=apl>
<syntaxhighlight lang=apl>
       1 0 1 0 0 0 0⊂'HiEarth'
       1 0 1 0 0 0 0⊂'HiEarth'
┌──┬─────┐
┌──┬─────┐
Line 11: Line 11:
== Non-Boolean left argument ==
== Non-Boolean left argument ==
Almost all dialects restrict the left argument to provide only the above functionality. However, the left argument can be interpreted as a count of how many partitions begin with a particular position:
Almost all dialects restrict the left argument to provide only the above functionality. However, the left argument can be interpreted as a count of how many partitions begin with a particular position:
<source lang=apl>
<syntaxhighlight lang=apl>
       2 0 3 0 0 0 0⊂'HiEarth'
       2 0 3 0 0 0 0⊂'HiEarth'
┌┬──┬┬┬─────┐
┌┬──┬┬┬─────┐
Line 19: Line 19:
== Short left argument ==
== Short left argument ==
The dialects that support this extension also allow omission of trailing zeros, which is useful if the partitioning vector is generated by [[indices#Inverse|where's inverse]]:
The dialects that support this extension also allow omission of trailing zeros, which is useful if the partitioning vector is generated by [[indices#Inverse|where's inverse]]:
<source lang=apl>
<syntaxhighlight lang=apl>
       ⍸⍣¯1⊢1 1 3 3 3
       ⍸⍣¯1⊢1 1 3 3 3
2 0 3
2 0 3
Line 29: Line 29:
== Long left argument ==
== Long left argument ==
Additional trailing empty divisions are created by adding an additional division count corresponding to the position beyond the end of the right argument:
Additional trailing empty divisions are created by adding an additional division count corresponding to the position beyond the end of the right argument:
<source lang=apl>
<syntaxhighlight lang=apl>
       1 0 1 0 0 0 0 1⊂'HiEarth'
       1 0 1 0 0 0 0 1⊂'HiEarth'
┌──┬─────┬┐
┌──┬─────┬┐
Line 39: Line 39:


[https://tio.run/##SyzI0U2pTMzJT9dNrShJzUtJTfn/qLdP/VHf1GBXvZRHbROqNQxtH3UufNS7S/NRx/JHvWvAnC1AvhVQEVABkJWSVqJg8Ki7BSKQkllcABSshQgAjdEAUuHB6uquZal5JerqGurqwanFxZn5eQFFmSABBXX1FHV1zUddi4EKnSOBvLS8YqCA@v/ggpzMEpAjHvVuVXjU1fSod4XCo94dj3oXH1pvqKAdowCkHrVNNtQB2ff/v7GCsYKJAliTgrpHfrljUWpkfqm9OgA Try it online!]
[https://tio.run/##SyzI0U2pTMzJT9dNrShJzUtJTfn/qLdP/VHf1GBXvZRHbROqNQxtH3UufNS7S/NRx/JHvWvAnC1AvhVQEVABkJWSVqJg8Ki7BSKQkllcABSshQgAjdEAUuHB6uquZal5JerqGurqwanFxZn5eQFFmSABBXX1FHV1zUddi4EKnSOBvLS8YqCA@v/ggpzMEpAjHvVuVXjU1fSod4XCo94dj3oXH1pvqKAdowCkHrVNNtQB2ff/v7GCsYKJAliTgrpHfrljUWpkfqm9OgA Try it online!]
<source lang=apl>
<syntaxhighlight lang=apl>
       Split←{⍵ ⊂⍨ ⍸⍣¯1 +\ ¯1↓1,⍺}
       Split←{⍵ ⊂⍨ ⍸⍣¯1 +\ ¯1↓1,⍺}
       3 3 4 Split 'HowAreYou?'
       3 3 4 Split 'HowAreYou?'

Revision as of 21:40, 10 September 2022

Partitioned Enclose () is a dyadic function which splits its right argument into differently sized pieces as determined by the left argument.

Basic functionality

In the simplest case, and on a vector right argument, the corresponding element in the left argument indicates where divisions begin: <syntaxhighlight lang=apl>

     1 0 1 0 0 0 0⊂'HiEarth'

┌──┬─────┐ │Hi│Earth│ └──┴─────┘ </source>

Non-Boolean left argument

Almost all dialects restrict the left argument to provide only the above functionality. However, the left argument can be interpreted as a count of how many partitions begin with a particular position: <syntaxhighlight lang=apl>

     2 0 3 0 0 0 0⊂'HiEarth'

┌┬──┬┬┬─────┐ ││Hi│││Earth│ └┴──┴┴┴─────┘ </source>

Short left argument

The dialects that support this extension also allow omission of trailing zeros, which is useful if the partitioning vector is generated by where's inverse: <syntaxhighlight lang=apl>

     ⍸⍣¯1⊢1 1 3 3 3

2 0 3

     2 0 3⊂'HiEarth'

┌┬──┬┬┬─────┐ ││Hi│││Earth│ └┴──┴┴┴─────┘ </source>

Long left argument

Additional trailing empty divisions are created by adding an additional division count corresponding to the position beyond the end of the right argument: <syntaxhighlight lang=apl>

     1 0 1 0 0 0 0 1⊂'HiEarth'

┌──┬─────┬┐ │Hi│Earth││ └──┴─────┴┘ </source>

Split into lengths

This above extensions allow a simple definition of a split-into-lengths function:

Try it online! <syntaxhighlight lang=apl>

     Split←{⍵ ⊂⍨ ⍸⍣¯1 +\ ¯1↓1,⍺}
     3 3 4 Split 'HowAreYou?'

┌───┬───┬────┐ │How│Are│You?│ └───┴───┴────┘ </source>

See also

External links

Tutorials

Documentation

APL built-ins [edit]
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Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
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