|P is for Practical
Perl Internals: Hashesby Kozz (Friar)
|on Apr 14, 2004 at 20:40 UTC
Kozz has asked for the wisdom of the Perl Monks concerning the following question:
Though I've been using Perl for several years, I've always taken for granted the ease of using hashes in all their incarnations. Now I've returned to school (for a CS degree) and while taking many data structures classes, have been wondering more about what are the internals of Perl's hashes.
I've looked online to find more info on how perl hashing works, and though some articles explain the different hash functions used through different perl versions, it's not clear:
I had written a small Perl script to perform a small task for an algorithms class, and the TA asked me about its true space efficiency versus another method which didn't use hashes, and I realized I couldn't tell him with any confidence how much memory my hash took up.
Any monks familiar with internals that would like to explain it? I suppose I could wade through the source, but... eek! I'm not a C programmer, either. Thanks!
Addendum / Bonus Question: Do Perl hashes differ in implementation versus "associative arrays" that appear in other languages? Do most other languages implement associative arrays internally in hash tables?