For C programmer's, declaring variables in Perl6 with state won't seem very foreign - just think static. In a nutshell, declaring a variable with state only initializes the variable once and any time the sub is re-invoked the variable retains its previous value. Update: This is inaccurate - read the authorative explanation.

Here is an example I, and others, wrote before Pugs had OO.

#!/usr/bin/pugs # Demo of the state() variable declaration. # This is also a neat way of doing OO without actually having OO avail +able. use v6; sub gen_cashier () { # This variable corresponds to a class variable. # It is shared across all "instances" of gen_cashier(). state $cash_in_store = 0; # One could add my() variables here, which correspond to instance +variables. # These would not be shared. # Finally, we return a hashref which maps method names to code. return { add => { $cash_in_store += $^amount }, del => { $cash_in_store -= $^amount }, bal => { $cash_in_store }, }; } my $drawer; $drawer[$_] = gen_cashier() for 1..3; $drawer[1]<add>( 59 ); $drawer[2]<del>( 17 ); say $drawer[3]<bal>(); # This should say "42"

The place I think it would come in most handy is for caching*. In p5, if a cache variable (%seen for instance) is supposed to belong to a sub that needs to persist across invocations, you need to do things like:

In Perl6, it will be as simple as:
sub foo () { state %seen; # ... }

So how will you use state declared variables in Perl6?

Cheers - L~R

The cache variable doesn't necessarily need to be used to calculate the return value of the sub which would be made easy using Memoize.