package OOscheme.visitor;
import OOscheme.*;

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

    /**
     * Returns inp[0].
     * @param host an empty list
     * @param inp Integer[] inp[0] is the minimum of the preceding list.
     * @return Integer
     */
    public Object emptyCase(IEmptyList host, Object... inp) {
        return inp[0];
    }

    /**
     * Recurs by passing the mimum between the host's first and inp, the
     * accumulated current minimum.
     * @param host a non-empty list
     * @param inp Integer[] inp[0] is the minimum of the preceding list.
     * @return Integer
     */
    public Object nonEmptyCase(INEList host, Object... inp) {
        int f = (Integer)host.getFirst();  // auto-unboxing
        int i = (Integer)inp[0];           // auto-unboxing
        return host.getRest().execute(this, Math.min(f, i));  // auto-boxing of Math.min(f, i)
    }
}