Pair.java

/**
 * 
 */
package x10.sncode;

public class Pair<S, T> {
    protected S fst;
    protected T snd;

    public Pair(S p1, T p2) {
        this.fst = p1;
        this.snd = p2;
    }

    public S fst() {
        return fst;
    }

    public T snd() {
        return snd;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof Pair) {
            Pair<?, ?> p = (Pair<?, ?>) obj;
            boolean r1 = fst == null ? p.fst == null : fst.equals(p.fst);
            boolean r2 = snd == null ? p.snd == null : snd.equals(p.snd);
            return r1 && r2;
        }
        return false;
    }

    @Override
    public int hashCode() {
        return (fst == null ? 0 : fst.hashCode()) + (snd == null ? 0 : snd.hashCode());
    }

    public String toString() {
        return "<" + fst + ", " + snd + ">";
    }
}