On Mon, 24 May 2010 13:36:01 -0400, Andrei Alexandrescu
<[email protected]> 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.
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.
Or is there another way to iterating the keys that would be more efficient
than building an array to contain the 'key' for each node?
-Steve
