4,493
edits
Tacit programming: Difference between revisions
Jump to navigation
Jump to search
→Tutorials
| (4 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
Tacit functions apply to implicit arguments. This is in contrast to the explicit use of arguments in [[ | Tacit functions apply to implicit arguments. This is in contrast to the explicit use of arguments in [[dfn]]s (<source inline lang=apl>⍺ ⍵</source>) and [[tradfn]]s (which have named arguments). Some APL dialects allow to combine functions into '''trains''' following a small set of rules. This allows creating complex derived functions without specifying any arguments explicitly. | ||
Known dialects which implement trains are [[Dyalog APL]], [[dzaima/APL]], [[ngn/apl]] and [[NARS2000]]. | Known dialects which implement trains are [[Dyalog APL]], [[dzaima/APL]], [[ngn/apl]] and [[NARS2000]]. | ||
| Line 36: | Line 36: | ||
A train is a series of functions in isolation. An isolated function is either surrounded by parentheses or named. Below, <source lang=apl inline>⍺</source> and <source lang=apl inline>⍵</source> refer to the arguments of the train. <source lang=apl inline>f</source>, <source lang=apl inline>g</source>, and <source lang=apl inline>h</source> are functions (which themselves can be tacit or not), and <source lang=apl inline>A</source> is an array. The arguments are processed by the following rules: | A train is a series of functions in isolation. An isolated function is either surrounded by parentheses or named. Below, <source lang=apl inline>⍺</source> and <source lang=apl inline>⍵</source> refer to the arguments of the train. <source lang=apl inline>f</source>, <source lang=apl inline>g</source>, and <source lang=apl inline>h</source> are functions (which themselves can be tacit or not), and <source lang=apl inline>A</source> is an array. The arguments are processed by the following rules: | ||
=== Forks === | |||
A 3-train is a ''fork'': | A 3-train is a ''fork'': | ||
{| | {| | ||
| Line 53: | Line 48: | ||
|- | |- | ||
|<source lang=apl>⍺ (A g h) ⍵</source>|| {{←→}} ||<source lang=apl>A g (⍺ h ⍵)</source> | |<source lang=apl>⍺ (A g h) ⍵</source>|| {{←→}} ||<source lang=apl>A g (⍺ h ⍵)</source> | ||
|} | |||
=== Atops === | |||
A 2-train is an ''atop'': | |||
{| | |||
|<source lang=apl> (g h) ⍵</source>|| {{←→}} ||<source lang=apl>g ( h ⍵)</source> | |||
|- | |||
|<source lang=apl>⍺ (g h) ⍵</source>|| {{←→}} ||<source lang=apl>g (⍺ h ⍵)</source> | |||
|} | |} | ||
| Line 195: | Line 198: | ||
666 ⍝ ⍎ executes original Accursed train | 666 ⍝ ⍎ executes original Accursed train | ||
</source> | </source> | ||
== See also == | |||
* [[Function composition]] | |||
== External links == | == External links == | ||
=== Tutorials === | === Tutorials === | ||
* Dyalog: [https://help.dyalog.com/16.0/Content/RelNotes14.0/Function%20Trains.htm version 14.0 release notes] | * Dyalog: [https://help.dyalog.com/16.0/Content/RelNotes14.0/Function%20Trains.htm version 14.0 release notes] | ||
* [[Dfns workspace]]: [https://dfns.dyalog.com/n_tacit.htm Translation of <nowiki>[dfns]</nowiki> into tacit form] | |||
* [[APL Cultivation]]: [https://chat.stackexchange.com/rooms/52405/conversation/lesson-23-transcribing-to-and-reading-trains Transcribing to and reading trains] | * [[APL Cultivation]]: [https://chat.stackexchange.com/rooms/52405/conversation/lesson-23-transcribing-to-and-reading-trains Transcribing to and reading trains] | ||
* [[APLtrainer]]: [https://www.youtube.com/watch?v=kt4lMZbn-so How to read trains in Dyalog APL code] (video) | * [[APLtrainer]]: [https://www.youtube.com/watch?v=kt4lMZbn-so How to read trains in Dyalog APL code] (video) | ||