package org.xwt.js;
import java.util.*;
import org.xwt.util.*;

// FEATURE: static slots for four objects?
/** A sensible implementation of the abstract methods in the JS class */
public class JSObj extends JS {
    
    // this gets around a wierd fluke in the Java type checking rules for ?..:
    public static final Object T = Boolean.TRUE;
    public static final Object F = Boolean.FALSE;

    // FEATURE: be smart here; perhaps intern
    public static final Number N(int i) { return new Integer(i); }
    public static final Number N(long l) { return new Long(l); }
    public static final Number N(double d) { return new Double(d); }
    public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; }
    
    private static Enumeration emptyEnumeration = new Enumeration() {
            public boolean hasMoreElements() { return false; }
            public Object nextElement() { throw new NoSuchElementException(); }
        };
    
    private Hash entries = null;
    public JSObj() { }
    public Enumeration keys() { return entries == null ? emptyEnumeration : entries.keys(); }
    public Object get(Object key) { return entries == null ? null : entries.get(key, null); }
    public void put(Object key, Object val) { if (entries == null) entries = new Hash(); entries.put(key, null, val); }

    // note that we don't actually implement trappable... we just provide these for subclasses which choose to
    public JSTrap getTrap(Object key) { return entries == null ? null : (JSTrap)entries.get(key, JSTrap.class); }
    public void putTrap(Object key, JSTrap t) { if (entries == null) entries = new Hash(); entries.put(key, JSTrap.class, t); }
}