Okay, I think I'm there, but I'd like to check I'm not doing anything dangerous, and I have one mystery...

Here's the code (I've included the contents of the FP files at the end).

use strict;

{
  package FP;
  sub foo{};
}

package GP;
{
  sub subtest1{return 'Global Test 1';}
  sub subtest2{return 'Global Test 2';}
}

package LP;
{
  sub subtest1{return 'Local Test 1';}
}

{
  package AP;
  use base qw(FP LP GP);
}

#delete_FP(0);
my $FP = 'test1.lib';
require $FP;

print "test1.lib\n";
print GP::subtest1() . "\n"; # uses GP
print FP::subtest1() . "\n"; # use FP subs defined in test1.lib
print AP->subtest1() . "\n"; # as previous
print AP->subtest2() . "\n"; # uses GP as this sub only defined there
print AP->subtest3() . "\n"; # this sub won't exist in a moment...

delete_FP($FP);
$FP = 'test2.lib';
require $FP;

print "\ntest2.lib\n";
print FP::subtest1() . "\n"; # uses FP subs defined in test2.lib
print AP->subtest1() . "\n"; # as previous
print AP->subtest3() . "\n"; # this sub now doesn't exist...

sub delete_FP{
  no strict 'refs';
  my $class = 'FP';
  my $symtab = $class . '::';
  # Delete all symbols except other namespaces
  for my $symbol (keys %{$symtab}) {
    next if $symbol =~ /\A[^:]+::\z/;
    delete $symtab->{$symbol};
  }
  delete $INC{$_[0]} if $_[0]; # in theory not nec. but tidier and all
+ows us to require the same lib again?
  return 1;
}

__END__
#test1.lib file

use strict;
package FP;
sub subtest1{
  return 'FP Test 1';
}
sub subtest3{
  return 'FP Test 3';
}

1;

#test2.lib file

use strict;
package FP;
sub subtest1{
  return 'FP Test 2';
}

1;
[download]

One mystery - there is a commented out call to delete_FP at line 24. If I don't comment this out, I get an error when I get to "print FP::subtest1()" on line 30, although the subsequent call to delete_FP seems to work fine - any ideas?

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**2
-$d**2+$b);$c=$d**2+$e**2>4?$d=8:_}1..50;print$c}0..59;print$/}0..20
[download]