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→Order of evaluation
Miraheze>Adám Brudzewsky |
Miraheze>Adám Brudzewsky |
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</source> | </source> | ||
That didn't work! This is because APL dispenses with traditional mathematics' confusing and inconsistent precedence order<ref>K.E. Iverson, [https://www.jsoftware.com/papers/EvalOrder.htm Conventions Governing Order of Evaluation] | That didn't work! This is because APL dispenses with traditional mathematics' confusing and inconsistent precedence order<ref>[[Ken Iverson|K.E. Iverson]], Appendix A: [https://www.jsoftware.com/papers/EvalOrder.htm Conventions Governing Order of Evaluation], Elementary Functions: An Algorithmic Treatment). Science Research Associates, 1966</ref>, replacing it with a simple right-to-left rule: | ||
<source lang=apl> | <source lang=apl> | ||
(⍳5)!4 | (⍳5)!4 | ||
1 4 6 4 1 | 1 4 6 4 1 | ||
</source> | </source> | ||
== Swapping arguments == | == Swapping arguments == | ||
If the arguments of <source lang=apl inline>!</source> were swapped, we didn't need that parenthesis. Enter the [[operator]] (higher-order function) [[swap]] (<source lang=apl inline>⍨</source>) which takes a [[dyadic]] function on its left and creates a new [[derived function]] which is identical to the original, but has swapped arguments: | If the arguments of <source lang=apl inline>!</source> were swapped, we didn't need that parenthesis. Enter the [[operator]] (higher-order function) [[swap]] (<source lang=apl inline>⍨</source>) which takes a [[dyadic]] function on its left and creates a new [[derived function]] which is identical to the original, but has swapped arguments: | ||