Idea: swap with multiple arguments

[Wyatt via Digitalmars-d]

On Tuesday, 24 May 2016 at 12:22:01 UTC, H. S. Teoh wrote:
>
> And why would you assume that it would rotate right? The 
> default assumption, unless stated clearly and widely followed 
> everywhere, is unclear and leads to misunderstandings. I'd 
> rather unambiguously name them rotateRight and rotateLeft than 
> the asymmetric rotate / rotateLeft.
>
In the APL family, we have dyadic ⌽ and ⊖:
       3⌽⍳9 ⍝ left
4 5 6 7 8 9 1 2 3
       ¯3⌽⍳9 ⍝ right
7 8 9 1 2 3 4 5 6
       3 3⍴⍳9
1 2 3
4 5 6
7 8 9
       1⊖3 3⍴⍳9 ⍝ up
4 5 6
7 8 9
1 2 3
       ¯1⊖3 3⍴⍳9 ⍝ down
7 8 9
1 2 3
4 5 6

They rotate left and up in the positive case because that yields 
the natural indexing order.  Right rotation gives you a reverse 
ordering.

-Wyatt