Re: A set type implemented as an AA wrapper

[mark via Digitalmars-d-learn]

On Thursday, 12 March 2020 at 16:02:14 UTC, H. S. Teoh wrote:
On Thu, Mar 12, 2020 at 08:51:24AM +0000, mark via 
Digitalmars-d-learn wrote: [...]
YYY: The range() method is clearly not good D style but I 
don't know
how to support foreach (item; aaset) ...

The usual idiom is to overload .opSlice, then you can do:

        foreach (item; aaset[]) { ... }

IOW rename .range to .opSlice.


ZZZ: I can't figure out how to support the in operator.

Note that 'x in aa' returns a pointer, not a bool.  You could 
try:

        bool opBinaryRight(string op : "in")(T lhs) {
                return (lhs in set) !is null;
        }

I renamed .range to .opSlice (and deleted the alias range this) 
and  foreach(item; aaset) works fine.

As for the != null, that was a mistake (due to Java) which I've 
now fixed.

I'm hoping to add union & intersection soon too.

Thanks.