+import org.xwt.*;
+import java.io.*;
+import java.util.*;
+
+/** The minimum set of functionality required for objects which are manipulated by JavaScript */
+public class JS extends org.xwt.util.BalancedTree {
+
+ public static final Object METHOD = new Object();
+ public final JS unclone() { return _unclone(); }
+ public Enumeration keys() throws JSExn { return entries == null ? emptyEnumeration : entries.keys(); }
+ public Object get(Object key) throws JSExn { return entries == null ? null : entries.get(key, null); }
+ public void put(Object key, Object val) throws JSExn { (entries==null?entries=new Hash():entries).put(key,null,val); }
+ public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
+ throw new JSExn("attempted to call the null value (method "+method+")");
+ }
+ public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
+ throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")");
+ }
+
+ JS _unclone() { return this; }
+ public static class Cloneable extends JS {
+ public Cloneable() { }
+ public Object jsclone() throws JSExn {
+ throw new JSExn("cloning not yet implemented");
+ }
+ }
+
+ public static class Clone extends JS.Cloneable {
+ protected JS.Cloneable clonee = null;
+ JS _unclone() { return clonee.unclone(); }
+ public JS.Cloneable getClonee() { return clonee; }
+ public Clone(JS.Cloneable clonee) { this.clonee = clonee; }
+ public boolean equals(Object o) {
+ if (!(o instanceof JS)) return false;
+ return unclone() == ((JS)o).unclone();
+ }
+ public Enumeration keys() throws JSExn { return clonee.keys(); }
+ public Object get(Object key) throws JSExn { return clonee.get(key); }
+ public void put(Object key, Object val) throws JSExn { clonee.put(key, val); }
+ public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
+ return clonee.callMethod(method, a0, a1, a2, rest, nargs);
+ }
+ public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
+ return clonee.call(a0, a1, a2, rest, nargs);
+ }
+ }
+
+ // Static Interpreter Control Methods ///////////////////////////////////////////////////////////////
+
+ /** log a message with the current JavaScript sourceName/line */
+ public static void log(Object message) { info(message); }
+ public static void debug(Object message) { Log.debug(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
+ public static void info(Object message) { Log.info(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
+ public static void warn(Object message) { Log.warn(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
+ public static void error(Object message) { Log.error(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
+
+ public static class NotPauseableException extends Exception { NotPauseableException() { } }
+
+ /** returns a callback which will restart the context; expects a value to be pushed onto the stack when unpaused */
+ public static UnpauseCallback pause() throws NotPauseableException {
+ Interpreter i = Interpreter.current();
+ if (i.pausecount == -1) throw new NotPauseableException();
+ i.pausecount++;
+ return new JS.UnpauseCallback(i);
+ }
+
+ public static class UnpauseCallback implements Scheduler.Task {
+ Interpreter i;
+ UnpauseCallback(Interpreter i) { this.i = i; }
+ public void perform() throws JSExn { unpause(null); }
+ public void unpause(Object o) throws JSExn {
+ // FIXME: if o instanceof JSExn, throw it into the JSworld
+ i.stack.push(o);
+ i.resume();
+ }
+ }
+
+
+
+ // Static Helper Methods ///////////////////////////////////////////////////////////////////////////////////
+
+ /** coerce an object to a Boolean */
+ public static boolean toBoolean(Object o) {
+ if (o == null) return false;
+ if (o instanceof Boolean) return ((Boolean)o).booleanValue();
+ if (o instanceof Long) return ((Long)o).longValue() != 0;
+ if (o instanceof Integer) return ((Integer)o).intValue() != 0;
+ if (o instanceof Number) {
+ double d = ((Number) o).doubleValue();
+ // NOTE: d == d is a test for NaN. It should be faster than Double.isNaN()
+ return d != 0.0 && d == d;
+ }
+ if (o instanceof String) return ((String)o).length() != 0;
+ return true;
+ }
+
+ /** coerce an object to a Long */
+ public static long toLong(Object o) { return toNumber(o).longValue(); }
+
+ /** coerce an object to an Int */
+ public static int toInt(Object o) { return toNumber(o).intValue(); }
+
+ /** coerce an object to a Double */
+ public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
+
+ /** coerce an object to a Number */
+ public static Number toNumber(Object o) {
+ if (o == null) return ZERO;
+ if (o instanceof Number) return ((Number)o);
+
+ // NOTE: There are about 3 pages of rules in ecma262 about string to number conversions
+ // We aren't even close to following all those rules. We probably never will be.
+ if (o instanceof String) try { return N((String)o); } catch (NumberFormatException e) { return N(Double.NaN); }
+ if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? N(1) : ZERO;
+ throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle");
+ }
+
+ /** coerce an object to a String */
+ public static String toString(Object o) {
+ if(o == null) return "null";
+ if(o instanceof String) return (String) o;
+ if(o instanceof Integer || o instanceof Long || o instanceof Boolean) return o.toString();
+ if(o instanceof JSArray) return o.toString();
+ if(o instanceof JSDate) return o.toString();
+ if(o instanceof Double || o instanceof Float) {
+ double d = ((Number)o).doubleValue();
+ if((int)d == d) return Integer.toString((int)d);
+ return o.toString();
+ }
+ throw new RuntimeException("can't coerce that!");
+ }
+
+ // Instance Methods ////////////////////////////////////////////////////////////////////
+
+ public static final Integer ZERO = new Integer(0);