[Issue 13903] std.array.removeIf for associative arrays

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13903

Iain Buclaw  changed:

   What|Removed |Added

   Priority|P1  |P4

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[Issue 13903] std.array.removeIf for associative arrays

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13903

--- Comment #3 from Steven Schveighoffer  ---
I think especially if you remove the CURRENT element while iterating you are in
for trouble.

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[Issue 13903] std.array.removeIf for associative arrays

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13903

Steven Schveighoffer  changed:

   What|Removed |Added

 CC||schvei...@yahoo.com

--- Comment #2 from Steven Schveighoffer  ---
(In reply to Seb from comment #1)

> auto removeIf(alias pred, AA)(AA aa)
> {
> aa.byPair.filter!(not!pred).each!(e => aa.remove(e.key));
> return aa;
> }

This implementation isn't valid. You can't remove while iterating. You would
need to somehow lock the AA from rehashing as you removed items.

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[Issue 13903] std.array.removeIf for associative arrays

[d-bugmail--- via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13903

Seb  changed:

   What|Removed |Added

 CC||greensunn...@gmail.com

--- Comment #1 from Seb  ---
Not sure whether such one/two-liners would be accepted to Phobos.

---
import std.experimental.all;

auto removeIf(alias pred, AA)(AA aa)
{
aa.byPair.filter!(not!pred).each!(e => aa.remove(e.key));
return aa;
}

void main()
{
auto aa = ["a" : 1, "b" : 2];
aa.removeIf!(a => a.key == "a").writeln;
}
---

But efficiency and bug-proneness are two good points.

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