dcollections 1.0 and 2.0a beta released

[Andrei Alexandrescu]

On 05/24/2010 03:18 PM, Steven Schveighoffer wrote:
> On Mon, 24 May 2010 15:58:46 -0400, Andrei Alexandrescu
> <SeeWebsiteForEmail at erdani.org> wrote:
>
>> On 05/24/2010 01:12 PM, Steven Schveighoffer wrote:
>>> On Mon, 24 May 2010 13:36:01 -0400, Andrei Alexandrescu
>>> <SeeWebsiteForEmail at erdani.org> wrote:
>>>
>>>> On 05/24/2010 12:11 PM, bearophile wrote:
>>>>> Steven Schveighoffer:
>>>>>> Is it unreasonable to expect to be able
>>>>>> to iterate the keys in a trie? (I don't really know, I've never
>>>>>> worked
>>>>>> with them)
>>>>>
>>>>> On tries you can iterate on all keys or on a sorted range of the keys.
>>>>
>>>> There's one more way of iteration that's unique to tries - by key
>>>> element (e.g. if key is string, you iterate by character). That would
>>>> be an exploratory iteration.
>>>>
>>>> At each step in the iteration you pass a character, so popFront()
>>>> takes an argument, it's popFront(char). trie.popFront('a') takes you
>>>> to all elements in the trie that start with 'a'. Then you can continue
>>>> exploring by e.g. trie.popFront('x') which takes you to all elements
>>>> that start with "ax". At any point the range may become dry (nothing
>>>> with this prefix). If the range is not empty, front() gives you
>>>> information about all strings that share the particular prefix you
>>>> have spanned (count and breadth comes to mind).
>>>
>>> That could be supported.
>>
>> To paraphrase a commercial, "there's an interface for that" :o).
>
> No there isn't. I wouldn't make that an interface, as it's not
> foreachable. I'd build a special range for it.
>
>>> But iterating over the keys, is that not advisable? Would your trie
>>> iterator be the only way to iterate over the elements? It seems rather
>>> non-useful.
>>
>> I think a trie, like many other nontrivial containers, supports
>> several means of iteration.
>
> Including keys?!!!
>
> Still not a straight answer. If you should be able to iterate keys, then
> say you should be able to iterate keys. If you shouldn't, then say that.

Sorry. Yes, by-key iteration should be possible.

Andrei