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#!./perl -w
# tests state variables
BEGIN {
chdir 't' if -d 't';
@INC = '../lib';
require './test.pl';
}
use strict;
use feature "state";
plan tests => 32;
ok( ! defined state $uninit, q(state vars are undef by default) );
# basic functionality
sub stateful {
state $x;
state $y = 1;
my $z = 2;
return ($x++, $y++, $z++);
}
my ($x, $y, $z) = stateful();
is( $x, 0, 'uninitialized state var' );
is( $y, 1, 'initialized state var' );
is( $z, 2, 'lexical' );
($x, $y, $z) = stateful();
is( $x, 1, 'incremented state var' );
is( $y, 2, 'incremented state var' );
is( $z, 2, 'reinitialized lexical' );
($x, $y, $z) = stateful();
is( $x, 2, 'incremented state var' );
is( $y, 3, 'incremented state var' );
is( $z, 2, 'reinitialized lexical' );
# in a nested block
sub nesting {
state $foo = 10;
my $t;
{ state $bar = 12; $t = ++$bar }
++$foo;
return ($foo, $t);
}
($x, $y) = nesting();
is( $x, 11, 'outer state var' );
is( $y, 13, 'inner state var' );
($x, $y) = nesting();
is( $x, 12, 'outer state var' );
is( $y, 14, 'inner state var' );
# in a closure
sub generator {
my $outer;
# we use $outer to generate a closure
sub { ++$outer; ++state $x }
}
my $f1 = generator();
is( $f1->(), 1, 'generator 1' );
is( $f1->(), 2, 'generator 1' );
my $f2 = generator();
is( $f2->(), 1, 'generator 2' );
is( $f1->(), 3, 'generator 1 again' );
is( $f2->(), 2, 'generator 2 once more' );
# with ties
{
package countfetches;
our $fetchcount = 0;
sub TIESCALAR {bless {}};
sub FETCH { ++$fetchcount; 18 };
tie my $y, "countfetches";
sub foo { state $x = $y; $x++ }
::is( foo(), 18, "initialisation with tied variable" );
::is( foo(), 19, "increments correctly" );
::is( foo(), 20, "increments correctly, twice" );
::is( $fetchcount, 1, "fetch only called once" );
}
# state variables are shared among closures
sub gen_cashier {
my $amount = shift;
state $cash_in_store = 0;
return {
add => sub { $cash_in_store += $amount },
del => sub { $cash_in_store -= $amount },
bal => sub { $cash_in_store },
};
}
gen_cashier(59)->{add}->();
gen_cashier(17)->{del}->();
is( gen_cashier()->{bal}->(), 42, '$42 in my drawer' );
# stateless assignment to a state variable
sub stateless {
(state $reinitme, my $foo) = (42, 'bar');
++$reinitme;
}
is( stateless(), 43, 'stateless function, first time' );
is( stateless(), 43, 'stateless function, second time' );
# array state vars
sub stateful_array {
state @x;
push @x, 'x';
return $#x;
}
my $xsize = stateful_array();
is( $xsize, 0, 'uninitialized state array' );
$xsize = stateful_array();
is( $xsize, 1, 'uninitialized state array after one iteration' );
# hash state vars
sub stateful_hash {
state %hx;
return $hx{foo}++;
}
my $xhval = stateful_hash();
is( $xhval, 0, 'uninitialized state hash' );
$xhval = stateful_hash();
is( $xhval, 1, 'uninitialized state hash after one iteration' );
# state declaration with a list
sub statelist {
# note that this should be a state assignment, while (state $lager, state $stout) shouldn't
state($lager, $stout) = (11, 22);
$lager++;
$stout++;
"$lager/$stout";
}
my $ls = statelist();
is($ls, "12/23", 'list assignment to state scalars');
$ls = statelist();
is($ls, "13/24", 'list assignment to state scalars');
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