examples/cashiers.pl

   1 # Demo of the state() variable declaration.
   2 # This is also a neat way of doing OO without actually having OO available.
   3 #
   4 # Please remember to update t/examples/examples.t and rename
   5 # examples/output/cashiers if you rename/move this file.
   6
   7 use v6;
   8
   9 sub gen_cashier () {
  10     # This variable corresponds to a class variable.
  11     # It is shared across all "instances" of gen_cashier().
  12     state $cash_in_store = 0;
  13
  14     # One could add my() variables here, which correspond to instance variables.
  15     # These would not be shared.
  16
  17     # Finally, we return a hashref which maps method names to code.
  18     return {
  19         add => { $cash_in_store += $^amount },
  20         del => { $cash_in_store -= $^amount },
  21         bal => { $cash_in_store             },
  22     };
  23 }
  24
  25 my @drawer;
  26 @drawer[$_] = gen_cashier() for 1..3;
  27
  28 @drawer[1]<add>( 59 );
  29 @drawer[2]<del>( 17 );
  30 say @drawer[3]<bal>();  # This should say "42"