use Data::Dumper;
use strict;
use warnings;

use constant SUCCEED => qr{(?=)};
use constant FAIL    => qr{(?!)};

my $QUOTED = qr/".+?"/;
my $NUM = qr/\d*\.\d*/;

my $VALUE  = do {
    use re 'eval';
    qr/(?:$QUOTED|$NUM)(??{'.' eq $& ? FAIL : SUCCEED})/;
};

my $text = 'name => "foo", fav.num => 3.123';
my @text = split /($VALUE)/ => $text;
print Dumper \@text;

__END__

C:\temp>perl re.pl
$VAR1 = [
          'name => ',
          '"foo"',
          ', fav.num => ',
          '3.123'
        ];