Iterators recap

[Sean Kelly]

Bill Baxter wrote:
> Sean Kelly wrote:
>> Bill Baxter wrote:
>>> Sean Kelly wrote:
>>>> Bill Baxter wrote:
>>>>>
>>>>> Too bad the iterator discussions fizzled out without anything 
>>>>> getting decided.
>>>>
>>>> I think the design was pretty well settled when things ended.  The 
>>>> next step would be a sample implementation so folks could wrangle 
>>>> over syntax.  It's on my "to do" list, but I'm a bit short on free 
>>>> time at the moment.
>>>
>>> Huh.  So what is your understanding of what the consensus was?
>>
>> Java-style, with random access iterators overloading array operations. 
>> I can't remember if there was any clear preference for the 
>> hasNext/getNext vs. the atEnd/getVal approach, but I tend to favor the 
>> latter.
> 
> I like next/value/(ptr) myself.
> Makes for very succinct while loops.  ptr available where it makes sense.
> 
> while(iter.next()) {  writefln(iter.value); }
> 
> while(iter.next()) {  *iter.ptr = 17; }

It's great for loops, but can be confusing when iterators stick around 
for a while.  Say I have some code that operates on the current value of 
an iterator.  With the next() approach, how do I know whether the 
iterator is valid?  Still, perhaps a hybrid approach is best.  Have next 
return true on success and offer an atEnd property as well.


Sean