package Functions::Base; use strict; use Exporter; our @ISA = qw(Exporter); our @EXPORT_OK = qw(func1 func2 func3); sub func1 { print "hello"; } sub func2 { print "kind"; } sub func3 { print "world"; } return 1; #### package Functions::Alternate; use strict; use Exporter; use Functions::Base (@Functions::Base::EXPORT_OK); our @ISA = qw(Exporter); our @EXPORT_OK = (@Functions::Base::EXPORT_OK, qw (funcx funcy) ); # func1 is going to be replaced with our own no warnings 'redefine'; sub func1 { print "goodbye"; } # func2 is going to be replaced with our own sub func2 { Functions::Base::func2(); print "(haha)"; } use warnings 'redefine'; # func3 is reused from orig::functions unchanged # a couple new functions sub funcx { print "new x"; } sub funcy { print "new y"; } return 1; #### package Functions; use strict; use Exporter; use Functions::Base qw(func1 func3); use Functions::Alternate qw(func2); our @ISA = qw(Exporter); our @EXPORT_OK = (func1 func2 func3); return 1; #### use strict; use Functions::Base qw(func1 func2 func3); func1; func2; func3; print "\n"; #### use strict; use Functions::Alternate qw(func1 func2 func3); func1; func2; func3; print "\n"; #### use strict; use Functions qw(func1 func2 func3); func1; func2; func3; print "\n";