package OOscheme.Visitor;
import OOscheme.*;

public class GetMinHelper implements IListAlgo {
    /**
     * Singleton Pattern.
     */
    public static final GetMinHelper Singleton = new GetMinHelper();
    private GetMinHelper() {
    }

    /**
     * Returns inp.
     * @param host an EmptyList
     * @param inp Integer the minimum of the preceding list.
     * @return Integer
     */
    public Object emptyCase(AList host, Object inp) {
        return inp;
    }

    /**
     * Recurs by passing the mimum between the host's first and inp, the
     * accumulated current minimum.
     * @param host an NEList.
     * @param inp Integer the minimum of the preceding list.
     * @return Integer
     */
    public Object nonEmptyCase(AList host, Object inp) {
        int f = ((Integer)host.getFirst()).intValue();
        int i = ((Integer)inp).intValue();
        return host.getRest().execute(this, new Integer(Math.min(f, i)));
    }
}