#tested
my %dispatch = (
  INTEGER   => \&checkInteger,
  DATE      => \&checkDate,
  IPADDRESS => \&checkIpaddress,
  FOO       => \&checkFoo
);

my $type   = "INTEGER";
my $answer = "44";

die "can't do $type" unless exists $dispatch{$type};
my $convAnswer = $dispatch{$type}->($answer);

sub checkInteger   { print "int"  }
sub checkDate      { print "date" }
sub checkIpaddress { print "ip"   }
sub checkFoo       { print "foo"  }