Is there a function for this?

[bauss]

On Saturday, 6 October 2018 at 13:34:44 UTC, Adam D. Ruppe wrote:
> On Saturday, 6 October 2018 at 13:17:22 UTC, bauss wrote:
>> My first thought was "uniq", but it can't really do it like 
>> that, but it doesn't work.
>
> uniq needs it to be sorted first, it only compares side-by-side 
> (to avoid allocating space to remember what it has already seen)
>
>> Is there another function in Phobos that perhaps would work?
>
> If the set is small enough and it is at least a forward range, 
> you could do a O(n^2) search with like filter with !canFind 
> (making sure the one it finds is not the one you are currently 
> looking at).
>
> But I think you are better off doing your own thing. I like to 
> just stick them all in an associative array, then loop over 
> that. The duplicate keys will naturally be filtered that way.
>
> Of course, it allocates memory for that but that's often 
> preferable to running the expensive search anyway.

It "can" be a big set, but it's probably the most straightforward 
way for now thought.

On Saturday, 6 October 2018 at 13:38:34 UTC, Nicholas Wilson 
wrote:
> On Saturday, 6 October 2018 at 13:17:22 UTC, bauss wrote:
>> Let's say you have a range with struct, but some of the struct 
>> are duplicates of each other.
>>
>> Is there a standard function in Phobos to remove duplicates?
>>
>> My first thought was "uniq", but it can't really do it like 
>> that, but it doesn't work.
>>
>> See: https://run.dlang.io/is/IcFEtw
>>
>> Is there another function in Phobos that perhaps would work?
>>
>> I can of course write my own function, but if there is a 
>> standard function that can do it, then I'd rather use that.
>
> range
>     .array.sort // make equal elements be adjacent
>     .chunks!"a==b" // get a range over those equal elements
>     .map(e => e.front); // get the first one
>
> should work, possibly not the most efficient way to do it 
> though.
>
> I don't know off the top of mu head if there are any to 
> preserve the order or the original range.

That doesn't work tbh. won't even compile.