Yeah, but I really don't like hashes. I like to keep my data in the order I want it to be in. It's a completely irrational and unfounded prejudice, I know, but it's still there. | [reply] |
That's like saying I like Carpentry but I don't like drills. Then you spend your time trying to bore a hole with your screwdriver, the cabinet takes for ever to build and it's not all that sturdy.
Or, I'm going to write a novel, but I'm not going to use adjectives.
Hashes are one of the basic tools of the language. You wouldn't code a large C project without pointers, would you?
Problems that would be innefficient using arrays like existance checks and counting occurances are quick and painless with hashes. And order is as simple as:
foreach (sort keys %hash) {
my $item = $hash{$_};
...
}
Not much worse than:
foreach my $item (@array) {
...
}
Plus there is no effort involved in inserting and delete and maintaining order.
I usually judge the progress of junior perl programmers by their use of hashes. When they stop trying to use arrays to do the job of a hash, they've leveled up in perl. (BTW, regexp are the second tier, then map/grep)
Of course this is all just my opinion,
-pete
Entropy is not what is used to be. | [reply]
[d/l]
[select] |
If your concern is just in keeping the names in the same
order in which they're seen, there are two approaches. The
easiest is to look into Tie::IxHash. This is a
variant of the hash that preserves the order of keys as
they are inserted.
The second way, that doesn't require installing a new
module, is to have your loop also push all newly-discovered
names onto an array, then use the array to iterate over the
hash rather than the keys keyword.
Don't be so quick to dismiss the basic constructs that
Perl provides. They are here for a reason, and when you ask
a very basic question you have to expect that your initial
answers are going to be pointers to the these basic
elements. At the very least, if you are going to ask such
a basic question then you should state up front why
you don't want to use the basic solution.
--rjray
| [reply] |