On Friday, 23 January 2015 at 20:28:32 UTC, Andrei Alexandrescu
wrote:
On 1/23/15 12:19 PM, Ary Borenszweig wrote:
In most languages group by yields a tuple of {group key, group
values}.
Interesting, thanks. Looks like we're at a net loss of
information with our current approach.
@quickfur, do you think you could expose a tuple with "key" and
"values"? The former would be the function value, the latter
would be what we offer right now.
That would apply only to the unary version of groupBy.
Andrei
groupby hack below ? I haven't yet read the source code and
don't feel I understand ranges deeply enough to know if this will
work in the general case. But it at least works for the example
(I think).
Laeeth.
#!/usr/bin/rdmd
void main()
{
import std.algorithm, std.stdio, std.range;
auto index=[293, 453, 600, 929, 339, 812, 222, 680, 529, 768];
auto vals=[ 1, 2, 3, 4, 5, 6,
7, 8, 9, 10];
auto zippy=zip(index,vals);
zippy.groupBy!(a=> a[0] & 1)
.writeln;
}
[root@fedorabox test]# ./groupby
[[Tuple!(int, int)(293, 1), Tuple!(int, int)(453, 2)],
[Tuple!(int, int)(600, 3)], [Tuple!(int, int)(929, 4),
Tuple!(int, int)(339, 5)], [Tuple!(int, int)(812, 6), Tuple!(int,
int)(222, 7), Tuple!(int, int)(680, 8)], [Tuple!(int, int)(529,
9)], [Tuple!(int, int)(768, 10)]]
