Short list with things to finish for D2

[Bill Baxter]

On Thu, Nov 19, 2009 at 5:17 PM, Leandro Lucarella <llucax at gmail.com> wrote:
> Bill Baxter, el 19 de noviembre a las 14:16 me escribiste:
>> > What I found hackish about it is that the code is a string manipulation
>> > mess. You can already do a string manipulation mess to programatically
>> > implement all the operator overloading.
>>
>> This is true, but if you leave it entirely up to the programmer and
>> string mixins, the mess is much more messy.
>> You're going to end up with code like this:
>>
>> mixin(genBinaryOp("+", q{MyType}, q{MyType rhs}, q{
>>     return this.impl + rhs.impl;
>> }));
>>
>>
>> instead of this:
>> MyType opBinary(string op : "+")(MyType rhs)  {
>>     return this.impl + rhs.impl;
>> }
>>
>> I would have a hard time defending the former as the recommended D style.
>> But the latter is not so bad.  It looks like a regular template
>> declaration, and code is code, not a string.
>
> But in this case you gained nothing comparing to opAdd(), where opBinary()
> is useful is where you use string mixins to avoid implementing the
> operators one by one.
>
> I know the opBinary() approach is less ugly than writing the code youself,
> but a library solution could be provided in the meantime (in the
> unexistent std.mixin module; which BTW, can't be named that way because
> "mixin" is a keyword ;).

My point was that the best you're going to be able to do with a
library solution (even for multiple operators) would be to provide a
"genBinaryOp" function, making your code look something like this:

mixin(genBinaryOps("+ - * /", q{MyType}, q{MyType rhs}, q{
    return this.impl $op rhs.impl;
}));

Or I guess with more effort you could probably have something like this:

mixin(genBinaryOps("+ - * /", q{
   MyType $opName(MyType rhs) {
       return this.impl $op rhs.impl;
   }
}));

But I still find the plain template idea cleaner for the user than a
string generation function that does heck knows what.

--bb