Adding Unicode operators to D

[Bill Baxter]

On Sun, Oct 26, 2008 at 11:02 PM, Simen Kjaeraas <simen.kjaras at gmail.com> wrote:
> On Sat, 25 Oct 2008 12:14:47 +0200, Spacen Jasset <spacenjasset at yahoo.co.uk>
> wrote:
>
>> Why unicode anyway? In the same way that editor support is required to
>> actually type them in, why not let the editor render them. So instead of
>> symbol 'x' in the source code, say:
>>
>> m3 = m1 cross_product m2
>>
>> as an infix notatation in a similar way to the (uniary) sizeof operator.
>>
>>
>> While cross_product is a bit long and unwieldy any editor capable can
>> replace the rendition of that keyword with a symbol for it. But in editors
>> that don't it means that it still can be typed in and/or displayed easily.
>>
>> Another option includes providing cross_product as an 'alias' and 'X'
>> aswell.
>>
>> Which then leads on to the introduction of a facility to add arbitary
>> operators, which could be interesting becuase you can supply any operator
>> you see fit for the domains that you use that require it. -- This provide
>> exactly the right solution though as all the additions would be 'non
>> standard' and I can see books in the future recommending people not use
>> unicode operators, becuase editors don't have support for them.
>
> This made me think. What if we /could/ define arbitrary infix operators in
> D? I'm thinking something along the lines of:
>
>
> operator cross_product(T, U)
> {
>  static if (T.opCross)
>  {
>    T.opCross(T)
>  }
>  else static if (U.opCross)
>  {
>    U.opCross_r(T);
>  }
>  else
>  {
>    static assert(false, "Operator not applicable to operands.");
>  }
> }
>
> alias cross_product ×;
>
>
> I'm not sure if this is possible, but it sure would please downs. :P

What's the precedence of your user-defined in-fix operator?

--bb