Partition: Difference between revisions
m (Text replacement - "</source>" to "</syntaxhighlight>") |
|||
| Line 1: | Line 1: | ||
{{Built-ins|Partition|⊆|⊂}} is a [[dyadic function]] which splits its right argument into differently sized pieces as determined by the non-negative integer left argument. This article uses <source lang=apl inline>⊆</ | {{Built-ins|Partition|⊆|⊂}} is a [[dyadic function]] which splits its right argument into differently sized pieces as determined by the non-negative integer left argument. This article uses <source lang=apl inline>⊆</syntaxhighlight> to distinguish Partition from [[Partitioned Enclose]] (which is always <source lang=apl inline>⊂</syntaxhighlight>), but the actual [[glyph]] used [[Migration level|varies by dialect]]. | ||
On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new '''division''' of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element): | On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new '''division''' of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element): | ||
| Line 9: | Line 9: | ||
│Hi│Earth│ | │Hi│Earth│ | ||
└──┴─────┘ | └──┴─────┘ | ||
</ | </syntaxhighlight> | ||
{{Works in|[[Dyalog APL]]}} | {{Works in|[[Dyalog APL]]}} | ||
Right argument elements can be skipped by having their corresponding left argument element be 0: | Right argument elements can be skipped by having their corresponding left argument element be 0: | ||
| Line 17: | Line 17: | ||
│Hi│Ear│ | │Hi│Ear│ | ||
└──┴───┘ | └──┴───┘ | ||
</ | </syntaxhighlight> | ||
{{Works in|[[Dyalog APL]]}} | {{Works in|[[Dyalog APL]]}} | ||
In the case where the left argument is [[Boolean]], Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function: | In the case where the left argument is [[Boolean]], Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function: | ||
| Line 31: | Line 31: | ||
│How│are│you?│ | │How│are│you?│ | ||
└───┴───┴────┘ | └───┴───┴────┘ | ||
</ | </syntaxhighlight> | ||
{{Works in|[[Dyalog APL]]}} | {{Works in|[[Dyalog APL]]}} | ||
== See also == | == See also == | ||
Revision as of 21:35, 10 September 2022
⊆ ⊂
|
Partition (⊆, ⊂) is a dyadic function which splits its right argument into differently sized pieces as determined by the non-negative integer left argument. This article uses <source lang=apl inline>⊆</syntaxhighlight> to distinguish Partition from Partitioned Enclose (which is always <source lang=apl inline>⊂</syntaxhighlight>), but the actual glyph used varies by dialect.
On a vector right argument, the arguments must have the same length with each element in the left argument corresponding to an element in the right argument. Partition begins a new division of its right argument whenever a left argument element is greater than its neighbour on the left (with a 0 assumed to the left of the first element):
Try it online! <source lang=apl>
1 1 2 2 2 2 2⊆'HiEarth'
┌──┬─────┐ │Hi│Earth│ └──┴─────┘ </syntaxhighlight>
Right argument elements can be skipped by having their corresponding left argument element be 0: <source lang=apl>
1 1 2 2 2 0 0⊆'HiEarth'
┌──┬───┐ │Hi│Ear│ └──┴───┘ </syntaxhighlight>
In the case where the left argument is Boolean, Partition splits its right argument on runs of 0s in the left argument, allowing a very short split-on-delimiter function:
Try it online! <source lang=apl>
1 1 1 0 1 1 1 0 1 1 1 1⊆'How are you?'
┌───┬───┬────┐ │How│are│you?│ └───┴───┴────┘
' '(≠⊆⊢)'How are you?'
┌───┬───┬────┐ │How│are│you?│ └───┴───┴────┘ </syntaxhighlight>