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digitalmars.D.learn - Algorithm remove Tid

reply "Casper =?UTF-8?B?RsOmcmdlbWFuZCI=?= <shorttail hotmail.com> writes:
import std.algorithm;
import std.concurrency;

void main() {
	Tid[] tids = [];
	Tid tid = thisTid;
	tids ~= tid;
	tids.remove(tid);
}

Why does this not compile?
Jan 22 2014
parent reply "monarch_dodra" <monarchdodra gmail.com> writes:
On Wednesday, 22 January 2014 at 12:11:22 UTC, Casper Færgemand 
wrote:
 import std.algorithm;
 import std.concurrency;

 void main() {
 	Tid[] tids = [];
 	Tid tid = thisTid;
 	tids ~= tid;
 	tids.remove(tid);
 }

 Why does this not compile?
Because "remove" takes an "offset" as an argument, not an element. To remove an element, I *think* you do it this way: tids = tids.remove!(a=>a == tid)();
Jan 22 2014
parent reply "Casper =?UTF-8?B?RsOmcmdlbWFuZCI=?= <shorttail hotmail.com> writes:
On Wednesday, 22 January 2014 at 13:16:18 UTC, monarch_dodra 
wrote:
 Because "remove" takes an "offset" as an argument, not an 
 element.

 To remove an element, I *think* you do it this way:

 tids = tids.remove!(a=>a == tid)();
Thanks a lot. I was trying to get that part to work, but I had a hard time realizing that => was a lambda and not a >=. x.x
Jan 22 2014
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
Casper Færgemand:

 To remove an element, I *think* you do it this way:

 tids = tids.remove!(a=>a == tid)();
is that removing only 0 or 1 items? Bye, bearophile
Jan 22 2014
next sibling parent "Casper =?UTF-8?B?RsOmcmdlbWFuZCI=?= <shorttail hotmail.com> writes:
On Wednesday, 22 January 2014 at 13:51:51 UTC, bearophile wrote:
 Casper Færgemand:

 To remove an element, I *think* you do it this way:

 tids = tids.remove!(a=>a == tid)();
is that removing only 0 or 1 items? Bye, bearophile
It removes all items that match the tid.
Jan 22 2014
prev sibling parent reply "monarch_dodra" <monarchdodra gmail.com> writes:
On Wednesday, 22 January 2014 at 13:51:51 UTC, bearophile wrote:
 Casper Færgemand:

 To remove an element, I *think* you do it this way:

 tids = tids.remove!(a=>a == tid)();
is that removing only 0 or 1 items? Bye, bearophile
Maybe you confusing the new style lambda for a "greater equal" operator? I can't make sense of your question any other way.
Jan 22 2014
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
monarch_dodra:

 Maybe you confusing the new style lambda for a "greater equal" 
 operator? I can't make sense of your question any other way.
My point was that the shown code doesn't remove only one item in presence of duplicated ones. In this case tid are unique, but in general using that code to remove one item is not a good idea. Bye, bearophile
Jan 22 2014
parent reply "monarch_dodra" <monarchdodra gmail.com> writes:
On Wednesday, 22 January 2014 at 15:41:58 UTC, bearophile wrote:
 monarch_dodra:

 Maybe you confusing the new style lambda for a "greater equal" 
 operator? I can't make sense of your question any other way.
My point was that the shown code doesn't remove only one item in presence of duplicated ones. In this case tid are unique, but in general using that code to remove one item is not a good idea. Bye, bearophile
Ah... I see. Yeah, this will remove *all* items that match the TID. I'm not sure that's a problem in this context, but I you did want to remove "at most" 1 item, then this isn't the correct solution. There's no phobos solution for that, but I guess it would be written something like: template removeOne(alias pred, SwapStrategy s = SwapStrategy.stable) { Range removeOne(Range)(Range range) { auto result = range.save; auto f = find!pred(range); if (f.empty) return result; static if (s == SwapStrategy.stable) { auto ff = f.save; f.popFront(); ff.popBack; for ( ; !f.empty; f.popFront(), ff.popFront()) moveFront(f, ff); } else { move(find.back, find.front); } result.popBack(); return result; } } Disclaimer: Not actually tested. May also horribly fail on non-reference ranges.
Jan 22 2014
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
monarch_dodra:

 There's no phobos solution for that,
There will be. In the meantime use: items = items.remove(items.countUntil(needle)); See also: https://d.puremagic.com/issues/show_bug.cgi?id=10959 Bye, bearophile
Jan 22 2014
parent "monarch_dodra" <monarchdodra gmail.com> writes:
On Wednesday, 22 January 2014 at 16:48:45 UTC, bearophile wrote:
 monarch_dodra:

 There's no phobos solution for that,
There will be. In the meantime use: items = items.remove(items.countUntil(needle));
Hum... that requires iterating the range twice for a non-RA range. And you forgot a save: items = items.remove(items.save.countUntil(needle)); But it *is* much simpler.
 See also:
 https://d.puremagic.com/issues/show_bug.cgi?id=10959
Thx.
 Bye,
 bearophile
Jan 22 2014