sub mymap (&@) { my ( $code, @list ) = @_; map &$code, @list }

my @cbs;
sub reset_cbs { @cbs = ( sub { uc }, sub { lc } ); }
sub get_cb { push @cbs, shift(@cbs); return $cbs[0]; }

reset_cbs();
print(( mymap \&{ get_cb() }, qw( a b c d ) ), "|");
print(( mymap \&{ get_cb() }, qw( a b c d ) ), "\n");

reset_cbs();
print(( map   &{ get_cb() }, qw( a b c d ) ), "|");
print(( map   &{ get_cb() }, qw( a b c d ) ), "\n");
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abcd|ABCD
aBcD|aBcD
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