sub till
{
    my $state = lookupState(caller);
    croak('Fatal: till: Too few conditions for current state.')
     if ((2 * $state) >= @_);
    if ref($_[2 * $state]) eq 'SCALAR' {
        $state++ if ($_[2 * $state]);
    } elsif ref($_[2 * $state]) eq 'Regexp' {
        $state++ if (/$_[2 * $state]/);
    } elsif ref($_[2 * $state]) eq 'CODE' {
        $state++ if ($_[2 * $state]->($_));
    }
    saveState($state, caller);
    if ((2 * $state) >= @_) {          # final condition was true
        saveState(0, caller);
        return 0;
    }
    return 0 if ($state < 1);          # init condition still false
    return $_[2 * ($state - 1)]->($_);
}