On Friday, 27 July 2012 at 00:10:31 UTC, Brad Anderson wrote:
D uses ranges instead of iterators. You can read more about
them here: http://ddili.org/ders/d.en/ranges.html
I find ranges to be a vast improvement over iterators
personally (I use iterators extensively in C++ for my job and
lament not having ranges regularly).
On Friday, 27 July 2012 at 00:17:21 UTC, H. S. Teoh wrote:
D has something far superior: ranges.
http://www.informit.com/articles/printerfriendly.aspx?p=1407357&rll=1
Even better, they are completely implemented in the library. No
unnecessary language bloat just to support them.
I'm not very well up on ranges. I understand the general [1 ...
6] type of ranges, but I really don't see how custom range
functions could be as useful as the Yield support in VB.NET. I
mean, here's an example of an iterator in VB.NET:
Public Function InfiniteSequence(StartValue As Int32, Step As
Int32) As IEnumerable(Of Int32)
Do
Yield StartValue
StartValue += Step
Loop
End Function
Usage:
For Each N in InfiniteSequence(2, 2)
... do something with this sequence of even numbers ...
Next
Notice how this function is written like a synchronous loop, yet
yields a lazy-initialised infinite sequence of numbers. Granted,
it's not a particularly useful example, but trust me: Iterators
and Yield in .NET is *really* damn useful. I would go so far as
to say it was one of the language's best features.
I may be wrong, but it looks like I'd have to code a new class -
not to mention several specific functions and some kind of state
variable - just to simulate this functionality in D. Can anyone
clarify this for me?
