my %check = (
    foo => qr/^([[:alpha:]]+)$/,
    bar => qr/^([[:alpha:]]+)$/,
    baz => qr/^([[:alpha:]]+)$/,
    quux => qr/^([[:alpha:]]+)$/,
);

my %f;

for my $pname (keys %check) {;
    defined && /$check{$pname}/ ? $f{$pname} = $1 : untaint_fail($pname)
        for scalar param($pname);
}