On Fri, 04 Mar 2011 11:29:08 -0500, Magnus Lie Hetland
<mag...@hetland.org> wrote:
From what I understand, when you override iteration, you can either
implement the basic range primitives, permitting foreach to
destructively iterate over your object, or you can implement a custom
method that's called, and that must perform the iteration. The
destructiveness of the first option can, of course, be mitigated if you
use a struct rather than a class, and make sure that anything that would
be destroyed by popFront() is copied.
What I'm wondering is whether there is a way to do what Python does --
to construct/return an iterator (or, in this case, a range) that is used
during the iteration, rather than the object itself?
That's exactly how to do it.
I'm thinking about when you iterate directly over the object here. As
far as I can see, the solution used in the std.container is to use
opSlice() for this functionality. In other words, in order to iterate
over container foo, you need to use foreach(e; foo[])? Is there no way
to get this functionality directly (i.e., for foreach(e; foo))?
I believe someone has filed a bug for this, because TDPL has said this
should be possible.
But with the current compiler, you can use opApply to achieve that
behavior.
-Steve
