Also, since C<$x> is lexical, it can't be reached or modified by any Perl
code outside.
-Be aware that assignment to C<state> variables (as in C<state $x = 42>)
-are executed every time; to initialize (or re-initialize) an undefined
-state scalar, you can use, for example, the defined-or assignment :
-
- state $x //= initial_value();
+When combined with variable declaration, simple scalar assignment to C<state>
+variables (as in C<state $x = 42>) is executed only the first time. When such
+statements are evaluated subsequent times, the assignment is ignored. The
+behavior of this sort of assignment to non-scalar variables is undefined.
=head3 Persistent variables with closures
sub glob {
my $pat = shift;
my @got;
- local *D;
- if (opendir D, '.') {
- @got = grep /$pat/, readdir D;
- closedir D;
+ if (opendir my $d, '.') {
+ @got = grep /$pat/, readdir $d;
+ closedir $d;
}
return @got;
}