heatblazer has asked for the wisdom of the Perl Monks concerning the following question:
Hello again.
Recently I read a post about hash tables. Not Perl`s ones but the hashes as ADT ( mainly C ones ). The thread was that hashes are not exactly the better idea and are overused by many. The better solution there were trees ( red and black ) or just lists. So, what I wonder is: How Perl know your hashes and how it finds everything so fast. I`ve read few Perl books which worship hashes like a magic - you just refer to a key and here is your value. But let`s assume we have a hash with, for example over 1 000 000 entries as a word count and we then search for a word that just does not appear there? How in blazes Perl will know that there is not that word from a million of words!? I just picture a barrel filled with red and blue balls over a million and you have to tell that you are 100% there is no other colors by just looking at that barrel.
It`s no question of Perl`s powers, it`s a question of knowledge and something that is just interesting to me. Also are linked lists or trees implemented in Perl a good idea, since they are not generics? And how you can handle the memory globing if you make a list or a tree that can grow big with many data in no time. Can Perl operate memory chunks?
Edited
Here is the link: about the hash tables
Edited
Thank you everybody for the explanation and useful information you`ve proviede me. I was able to understand some of the magic we have here with hashes. Now I see how big difference is between C hash and Perl hash.