2009/8/5 Andrei Alexandrescu <andrei@metalanguage.com>:
Scott McMurray wrote:
On a related note, how would I, using ranges, sort only the first half of a partition? It appears I can only get a range for the second half[2]. In code, I'm looking for the equivalent of sort(b, partition(b, e, pred));
I made partial sorting available for random-access ranges (just like STL). For those it's easy to select the first half (e.g. in D by using r[0 .. r.length / 2]).
Sorry, that was unclear of me. When I said "half" I meant "the contiguous subsequence at the from of the original range in which the predicate is true". It looks like I have to do this (guessing at D syntax): falsepart = partition(r, pred); sort(r[0 .. r.size()-falsepart.size()]); Is there a more elegant way to do that? I don't have confidence that I haven't made an off-by-one error. Also, I presume partition works on bidirectional ranges for which I cannot use [] to get the range where the predicate is true. What if I wanted to run a bottom_up_merge_sort function on the "predicate is true" subrange of my list, for example? In short, it feels like partition should be returning a pair of ranges. (Though I haven't thought all the way through sentinel-terminated ranges and such. But I suppose they aren't bidirectional in the first place.)