Without: Difference between revisions
Jump to navigation
Jump to search
(Created page with "{{Built-in|Without|~}}, '''Excluding''', or '''Less''', is a dyadic set function which computes the set difference of the two vector [...") |
|||
Line 15: | Line 15: | ||
</source> | </source> | ||
== Extension == | |||
Some dialects allow Without to work on [[major cell]]s: | |||
[https://tio.run/##SyzI0U2pTMzJT9dNrShJzUtJTfn/P@JR2wQTBaNHvVvUHR2dnJyBQJ0rEihojBB0dFTnetQ3FSgYURf5/z8A Try it online!]<source lang=apl> | |||
X←4 2⍴'AABBCCCC' | |||
Y←3 2⍴'AABBAA' | |||
X~Y | |||
CC | |||
CC | |||
</source>{{Works in|[[Extended Dyalog APL]]}} | |||
Others can easily define such a function: | |||
[https://tio.run/##SyzI0U2pTMzJT///P@JR2wQTBaNHvVvUHR2dnJyBQJ0rEihojBB0dFTnCs8sycgvLQFKVD/q3fWoZ/@j3hV1Go96Nz/qXAQU0HzU0QUSB/J7t9ZyPeqbClQZoQDVpRD5/z8A Try it online!]<source lang=apl> | |||
X←4 2⍴'AABBCCCC' | |||
Y←3 2⍴'AABBAA' | |||
Without←{⍺⌿⍨~(⍳≢⍺)∊⍺⍳⍵} | |||
X Without Y | |||
CC | |||
CC | |||
</source>{{Works in|[[Dyalog APL]]}} | |||
== External Links == | == External Links == | ||
Revision as of 08:24, 11 June 2020
~
|
Without (~
), Excluding, or Less, is a dyadic set function which computes the set difference of the two vector arguments. It shares the glyph ~
with the monadic function Not.
Examples
Both arguments of Without is usually restricted to vectors. Unlike sets in the mathematical sense, duplicate elements are allowed in both sides, and Without is usually implemented as "left argument filtered by the absence in the right argument" (~X∊Y)/X
. This preserves the order and multiplicity in the left argument. Both arguments can be nested arrays.
'HELLO'~'GOODBYE' HLL A←'THIS' 'AND' 'THAT' A~'TH' 'AND' ┌────┬────┐ │THIS│THAT│ └────┴────┘
Extension
Some dialects allow Without to work on major cells:
X←4 2⍴'AABBCCCC' Y←3 2⍴'AABBAA' X~Y CC CC
Works in: Extended Dyalog APL
Others can easily define such a function:
X←4 2⍴'AABBCCCC' Y←3 2⍴'AABBAA' Without←{⍺⌿⍨~(⍳≢⍺)∊⍺⍳⍵} X Without Y CC CC
Works in: Dyalog APL
External Links
Documentation