1 // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
4 import org.ibex.util.*;
9 /** The minimum set of functionality required for objects which are manipulated by JavaScript */
10 public class JS extends org.ibex.util.BalancedTree {
12 public static boolean checkAssertions = false;
14 public static final Object METHOD = new Object();
15 public final JS unclone() { return _unclone(); }
16 public Enumeration keys() throws JSExn { return entries == null ? emptyEnumeration : entries.keys(); }
17 public Object get(Object key) throws JSExn { return entries == null ? null : entries.get(key, null); }
18 public void put(Object key, Object val) throws JSExn { (entries==null?entries=new Hash():entries).put(key,null,val); }
19 public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
20 throw new JSExn("attempted to call the null value (method "+method+")");
22 public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
23 throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")");
26 JS _unclone() { return this; }
27 public static class Cloneable extends JS {
28 public Object jsclone() throws JSExn {
29 return new Clone(this);
33 public static class Clone extends JS.Cloneable {
34 protected JS.Cloneable clonee = null;
35 JS _unclone() { return clonee.unclone(); }
36 public JS.Cloneable getClonee() { return clonee; }
37 public Clone(JS.Cloneable clonee) { this.clonee = clonee; }
38 public boolean equals(Object o) {
39 if (!(o instanceof JS)) return false;
40 return unclone() == ((JS)o).unclone();
42 public Enumeration keys() throws JSExn { return clonee.keys(); }
43 public Object get(Object key) throws JSExn { return clonee.get(key); }
44 public void put(Object key, Object val) throws JSExn { clonee.put(key, val); }
45 public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
46 return clonee.callMethod(method, a0, a1, a2, rest, nargs);
48 public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
49 return clonee.call(a0, a1, a2, rest, nargs);
53 // Static Interpreter Control Methods ///////////////////////////////////////////////////////////////
55 /** log a message with the current JavaScript sourceName/line */
56 public static void log(Object message) { info(message); }
57 public static void debug(Object message) { Log.debug(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
58 public static void info(Object message) { Log.info(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
59 public static void warn(Object message) { Log.warn(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
60 public static void error(Object message) { Log.error(Interpreter.getSourceName() + ":" + Interpreter.getLine(), message); }
62 public static class NotPauseableException extends Exception { NotPauseableException() { } }
64 /** returns a callback which will restart the context; expects a value to be pushed onto the stack when unpaused */
65 public static UnpauseCallback pause() throws NotPauseableException {
66 Interpreter i = Interpreter.current();
67 if (i.pausecount == -1) throw new NotPauseableException();
69 return new JS.UnpauseCallback(i);
72 public static class UnpauseCallback implements Scheduler.Task {
74 UnpauseCallback(Interpreter i) { this.i = i; }
75 public void perform() throws JSExn { unpause(null); }
76 public void unpause(Object o) throws JSExn {
77 // FIXME: if o instanceof JSExn, throw it into the JSworld
85 // Static Helper Methods ///////////////////////////////////////////////////////////////////////////////////
87 /** coerce an object to a Boolean */
88 public static boolean toBoolean(Object o) {
89 if (o == null) return false;
90 if (o instanceof Boolean) return ((Boolean)o).booleanValue();
91 if (o instanceof Long) return ((Long)o).longValue() != 0;
92 if (o instanceof Integer) return ((Integer)o).intValue() != 0;
93 if (o instanceof Number) {
94 double d = ((Number) o).doubleValue();
95 // NOTE: d == d is a test for NaN. It should be faster than Double.isNaN()
96 return d != 0.0 && d == d;
98 if (o instanceof String) return ((String)o).length() != 0;
102 /** coerce an object to a Long */
103 public static long toLong(Object o) { return toNumber(o).longValue(); }
105 /** coerce an object to an Int */
106 public static int toInt(Object o) { return toNumber(o).intValue(); }
108 /** coerce an object to a Double */
109 public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
111 /** coerce an object to a Number */
112 public static Number toNumber(Object o) {
113 if (o == null) return ZERO;
114 if (o instanceof Number) return ((Number)o);
116 // NOTE: There are about 3 pages of rules in ecma262 about string to number conversions
117 // We aren't even close to following all those rules. We probably never will be.
118 if (o instanceof String) try { return N((String)o); } catch (NumberFormatException e) { return N(Double.NaN); }
119 if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? N(1) : ZERO;
120 throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle");
123 /** coerce an object to a String */
124 public static String toString(Object o) {
125 if(o == null) return "null";
126 if(o instanceof String) return (String) o;
127 if(o instanceof Integer || o instanceof Long || o instanceof Boolean) return o.toString();
128 if(o instanceof JSArray) return o.toString();
129 if(o instanceof JSDate) return o.toString();
130 if(o instanceof Double || o instanceof Float) {
131 double d = ((Number)o).doubleValue();
132 if((int)d == d) return Integer.toString((int)d);
135 throw new RuntimeException("can't coerce "+o+" [" + o.getClass().getName() + "] to type String.");
138 // Instance Methods ////////////////////////////////////////////////////////////////////
140 public static final Integer ZERO = new Integer(0);
142 // this gets around a wierd fluke in the Java type checking rules for ?..:
143 public static final Object T = Boolean.TRUE;
144 public static final Object F = Boolean.FALSE;
146 public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; }
147 public static final Boolean B(int i) { return i==0 ? Boolean.FALSE : Boolean.TRUE; }
148 public static final Number N(String s) { return s.indexOf('.') == -1 ? N(Integer.parseInt(s)) : new Double(s); }
149 public static final Number N(double d) { return (int)d == d ? N((int)d) : new Double(d); }
150 public static final Number N(long l) { return N((int)l); }
152 private static final Integer[] smallIntCache = new Integer[65535 / 4];
153 private static final Integer[] largeIntCache = new Integer[65535 / 4];
154 public static final Number N(int i) {
156 int idx = i + smallIntCache.length / 2;
157 if (idx < smallIntCache.length && idx > 0) {
158 ret = smallIntCache[idx];
159 if (ret != null) return ret;
161 else ret = largeIntCache[Math.abs(idx % largeIntCache.length)];
162 if (ret == null || ret.intValue() != i) {
163 ret = new Integer(i);
164 if (idx < smallIntCache.length && idx > 0) smallIntCache[idx] = ret;
165 else largeIntCache[Math.abs(idx % largeIntCache.length)] = ret;
170 private static Enumeration emptyEnumeration = new Enumeration() {
171 public boolean hasMoreElements() { return false; }
172 public Object nextElement() { throw new NoSuchElementException(); }
175 private Hash entries = null;
177 public static JS fromReader(String sourceName, int firstLine, Reader sourceCode) throws IOException {
178 return JSFunction._fromReader(sourceName, firstLine, sourceCode);
181 // HACK: caller can't know if the argument is a JSFunction or not...
182 public static JS cloneWithNewParentScope(JS j, JSScope s) {
183 return ((JSFunction)j)._cloneWithNewParentScope(s);
187 // Trap support //////////////////////////////////////////////////////////////////////////////
189 /** override and return true to allow placing traps on this object.
190 * if isRead true, this is a read trap, otherwise write trap
192 protected boolean isTrappable(Object name, boolean isRead) { return true; }
194 /** performs a put, triggering traps if present; traps are run in an unpauseable interpreter */
195 public void putAndTriggerTraps(Object key, Object value) throws JSExn {
196 Trap t = getTrap(key);
197 if (t != null) t.invoke(value);
198 else put(key, value);
201 /** performs a get, triggering traps if present; traps are run in an unpauseable interpreter */
202 public Object getAndTriggerTraps(Object key) throws JSExn {
203 Trap t = getTrap(key);
204 if (t != null) return t.invoke();
205 else return get(key);
208 /** retrieve a trap from the entries hash */
209 protected final Trap getTrap(Object key) {
210 return entries == null ? null : (Trap)entries.get(key, Trap.class);
213 /** retrieve a trap from the entries hash */
214 protected final void putTrap(Object key, Trap value) {
215 if (entries == null) entries = new Hash();
216 entries.put(key, Trap.class, value);
219 /** adds a trap, avoiding duplicates */
220 protected final void addTrap(Object name, JSFunction f) throws JSExn {
221 if (f.numFormalArgs > 1) throw new JSExn("traps must take either one argument (write) or no arguments (read)");
222 boolean isRead = f.numFormalArgs == 0;
223 if (!isTrappable(name, isRead)) throw new JSExn("not allowed "+(isRead?"read":"write")+" trap on property: "+name);
224 for(Trap t = getTrap(name); t != null; t = t.next) if (t.f == f) return;
225 putTrap(name, new Trap(this, name.toString(), f, (Trap)getTrap(name)));
228 /** deletes a trap, if present */
229 protected final void delTrap(Object name, JSFunction f) {
230 Trap t = (Trap)getTrap(name);
231 if (t == null) return;
232 if (t.f == f) { putTrap(t.name, t.next); return; }
233 for(; t.next != null; t = t.next) if (t.next.f == f) { t.next = t.next.next; return; }