On Tuesday, 12 November 2013 at 16:34:30 UTC, bearophile wrote:
Daniel Davidson:
Yes, but that is only giving the dates. I want the actual
array elements. Suppose S is a large object with lots of extra
fields in addition to `string foo`. There should be a way to
pull out the lower bound based on a date without creating a
needle (S). Maybe lowerBound is not the right function?
Second try:
import std.stdio, std.range, std.datetime, std.algorithm,
std.array, std.typecons;
struct S {
Date date;
string foo;
}
void main() {
auto sarr = [S(Date(2000, 1, 1), "x"),
S(Date(2000, 2, 1), "a"),
S(Date(2000, 3, 1), "foo")];
assert(sarr.isSorted!q{ a.date < b.date });
sarr.writeln;
auto needle = S(Date(2000, 2, 1));
sarr
.map!(s => s.date)
.zip(sarr.length.iota)
.assumeSorted!q{ a[0] < b[0] }
.lowerBound(tuple(needle.date, 0))
.map!(p => sarr[p[1]])
.writeln;
}
Output:
[S(2000-Jan-01, "x"), S(2000-Feb-01, "a"), S(2000-Mar-01,
"foo")]
[S(2000-Jan-01, "x")]
Bye,
bearophile
Well, I think that is it. Thanks, bearophile!
Pardon the redirect, but while you are at it, I would appreciate
your take on this one
(http://forum.dlang.org/post/gofijmqwhfcwgbruz...@forum.dlang.org).
I'm sure you'll improve it and teach me a few things on the way
;-)
Thanks
Dan
