Re^3: need help with Tie::Judy

> I need a complete functioning example.

try this

use Tie::Judy;

tie %fruit_color, 'Tie::Judy';
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A hash represents a set of key/value pairs:
my %fruit_color = ("apple", "red", "banana", "yellow");
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You can use whitespace and the '=>' operator to lay them out more nicely:
my %fruit_color = (
    apple  => "red",
    banana => "yellow",
);
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To get at hash elements:
$fruit_color{"apple"};           # gives "red"
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You can get at lists of keys and values with keys() and values().
my @fruits = keys %fruit_color;
my @colors = values %fruit_color;
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see also Re: need help with Tie::Judy

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

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Re^4: need help with Tie::Judy by Bod (Parson) on Dec 06, 2020 at 01:02 UTC
I'm trying to understand what is happen with the sample code LanX has provided... The command `tie %fruit_color, 'Tie::Judy';` ties the associative array* `%fruit_color` to the class. From this point on, when `%fruit_color` is used, instead of the default Perl behaviour, the implementation is handled by `Tie::Judy` which implements alternative methods to the default methods used by Perl. In this case it does the same thing in a different way. Is that something like correct? * I deliberately didn't refer to `%fruit_color` here as a hash because in this case it is a Judy Array which is not a hash but another example of the same type of storage.	[reply] [d/l] [select]
Re^5: need help with Tie::Judy by LanX (Saint) on Dec 06, 2020 at 02:00 UTC
> Is that something like correct? more or less, yes. `The tie() function binds a variable to a class (package) that will provide the implementation for access methods for that variable. Once this magic has been performed, accessing a tied variable automatically triggers method calls in the proper class. The complexity of the class is hidden behind magic methods calls.` see also perltie#Tying-Hashes > I deliberately didn't refer to %fruit_color here as a hash No it's for sure a "tied hash" in this case implementing a "hash". Both is correct. Perl's generic term for associative arrays is "hash", no matter which implementation is used, so this is still a hash. But a "tied hash" actually only refers to the `%syntax` and connected hash operators. A tied hash may be used for any kind of magic, like e.g. making hash keys case insensitive `$hash{key} eq $hash{KEY}` returning the current time at different places `$time{London}` etc... see also Tie::Hash But - besides providing a different implementations for hashes - it's in my experience mostly only used for syntactic sugar. Most authors prefer providing an explicit OOP solution (like `$time->get("London")` ) and avoid the magic. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]