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Withe: Difference between revisions
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(Created page with "{{Built-in|Withe|⍩}} is a primitive operator which forms a hook. Called dyadically with function operands <source lang=apl inline>f</source> and...") |
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In usage, <source lang=apl inline>X f⍩g Y</source> is equivalent to <source lang=apl inline>X f g Y</source>, and <source lang=apl inline>f⍩g Y</source> is equivalent to <source lang=apl inline>Y f g Y</source>. Thus, Withe can be defined as the [[dop]] <source lang=apl inline>{⍺←⍵ ⋄ ⍺ ⍺⍺ ⍵⍵ ⍵}</source> and is equivalent to the [[derived function]] <source lang=apl inline>f∘g⍨⍨</source>. | In usage, <source lang=apl inline>X f⍩g Y</source> is equivalent to <source lang=apl inline>X f g Y</source>, and <source lang=apl inline>f⍩g Y</source> is equivalent to <source lang=apl inline>Y f g Y</source>. Thus, Withe can be defined as the [[dop]] <source lang=apl inline>{⍺←⍵ ⋄ ⍺ ⍺⍺ ⍵⍵ ⍵}</source> and is equivalent to the [[derived function]] <source lang=apl inline>f∘g⍨⍨</source>. | ||
Withe first appeared in [[A Dictionary of APL]],<ref>[[Ken Iverson]]. [[A Dictionary of APL]]. [https://www.jsoftware.com/papers/APLDictionary1.htm#withe Withe]. [[APL Quote Quad]], Volume 18, Number 1, 1987-09.</ref> but substituted by the 2-[[train]] in [[J]] after the proposal in [[Ken Iverson|Iverson]] and [[Eugene McDonnell|McDonnell]]'s paper ''Phrasal Forms''.<ref>[[Ken Iverson]] and [[Eugene McDonnell]]. [http://www.jsoftware.com/papers/fork.htm Phrasal forms] at [[APL89]].</ref> | Withe first appeared in [[A Dictionary of APL]],<ref>[[Ken Iverson]]. [[A Dictionary of APL]]. [https://www.jsoftware.com/papers/APLDictionary1.htm#withe Withe]. [[APL Quote Quad]], Volume 18, Number 1, 1987-09.</ref> but substituted by the 2-[[train]] in [[J]] after the proposal in [[Ken Iverson|Iverson]] and [[Eugene McDonnell|McDonnell]]'s paper ''Phrasal Forms''.<ref>[[Ken Iverson]] and [[Eugene McDonnell]]. [http://www.jsoftware.com/papers/fork.htm Phrasal forms] at [[APL89]].</ref> It is present in [[BQN]] as '''After''' (<code>⟜</code>).<ref>[[Marshall Lochbaum]]. ''Tutorial: Combinators''. [https://mlochbaum.github.io/BQN/tutorial/combinator.html#before-and-after Before and After]. Accessed 2021-09-01.</ref> | ||
== See also == | == See also == | ||