This is why you don't nest named subs, the closure becomes "static"
perl -E " sub f{ my %g; sub g{say \%g; } g(); say \%g; \%g } say f(),$/ for 1 .. 4;"
perl -E ' sub f{ my %g; sub g{say \%g; } g(); say \%g; \%g } say f(),$/ for 1 .. 4; '
HASH(0xabd9c4)
HASH(0xabd9c4)
HASH(0xabd9c4)
HASH(0xabd9c4)
HASH(0x3f9b6c)
HASH(0x3f9b6c)
HASH(0xabd9c4)
HASH(0x3f9b8c)
HASH(0x3f9b8c)
HASH(0xabd9c4)
HASH(0x3f9b6c)
HASH(0x3f9b6c)
By making the nested subroutine a variable (also known as an anonymous sub), the closure is dynamic
$ perl -lE " sub f{ my %g; my $g = sub {say \%g; $g{1}++}; $g->(); say \%g; \%g } say f(),$/ for 1 .. 4;"
HASH(0xabd9d4)
HASH(0xabd9d4)
HASH(0xabd9d4)
HASH(0x3f9b1c)
HASH(0x3f9b1c)
HASH(0x3f9b1c)
HASH(0x99b374)
HASH(0x99b374)
HASH(0x99b374)
HASH(0x99b344)
HASH(0x99b344)
HASH(0x99b344)
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