In the OPed code, the statement
BEGIN { say __PACKAGE__."::begin $variable"; }
refers to the lexical $variable scalar, but the BEGIN block executes first, after the $variable is declared, but before it is initialized at run time. Hence, it is uninitialized, but still consistent with strict. Changing the variable name makes this clear:
c:\@Work\Perl\monks>perl -wMstrict -le
"use strict;
use warnings;
use feature 'say';
;;
Foo->test('xxx');
;;
{
package Foo;
;;
my $variable = 'bar';
;;
BEGIN { say __PACKAGE__ . qq{::begin $vaRRRRiable}; }
;;
sub test { say $_[0], $_[1], $variable; }
}
;;
Foo->test('yyy');
"
Global symbol "$vaRRRRiable" requires explicit package name at -e line
+ 1.
BEGIN not safe after errors--compilation aborted at -e line 1.
Changing the scalar name back to
$variable accesses the lexical again, but it's still not initialized at the time the
BEGIN block runs, nor at the first invocation of
Foo->test('xxx'); (but it is initialized by the time
Foo->test('yyy'); runs):
c:\@Work\Perl\monks>perl -wMstrict -le
"use strict;
use warnings;
use feature 'say';
;;
Foo->test('xxx');
;;
{
package Foo;
;;
my $variable = 'bar';
;;
BEGIN { say __PACKAGE__ . qq{::begin $variable}; }
;;
sub test { say $_[0], $_[1], $variable; }
}
;;
Foo->test('yyy');
"
Use of uninitialized value $variable in concatenation (.) or string at
+ -e line 1.
Foo::begin
Use of uninitialized value $variable in say at -e line 1.
Fooxxx
Fooyyybar
Give a man a fish: <%-{-{-{-<
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