1 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
2 // Licensed under the Apache Public Source License 2.0 ("the License").
3 // You may not use this file except in compliance with the License.
7 import org.ibex.util.*;
11 /** The minimum set of functionality required for objects which are manipulated by JavaScript */
12 public interface JS extends Pausable {
14 /** Returns an enumeration of the keys in this object. */
15 public JS.Enumeration keys() throws JSExn;
17 /** Return the value associated with the given key. */
18 public JS get(JS key) throws JSExn;
20 /** Store a specific value against the given key. */
21 public void put(JS key, JS value) throws JSExn;
23 /** Executes or unpauses the task, running it in a
24 * <i>pausable</i> context. */
25 public Object run(Object o) throws Exception, AlreadyRunningException;
27 /** Pauses the running task at its convienience. */
28 public void pause() throws NotPausableException;
30 /** Calls a specific method with given arguments on this object.
31 * An exception is thrown if there is no such method or the
32 * arguments are invalid. */
33 public JS call(JS method, JS[] args) throws JSExn;
35 /** Calls this object with the given arguments, running it in an
36 * <i>unpausable</i> context. An exception is thrown if this
37 * object is not callable or the arguments are invalid. */
38 public JS call(JS[] args) throws JSExn;
40 /** Returns the names of the formal arguments, if any.
41 * This function must never return a null object. */
42 public String[] getFormalArgs();
44 /** Put a value to the given key, calling any write traps that have
45 * been placed on the key.
47 * This function may block for an indeterminate amount of time.
49 * Write traps may change the final value before it is put, thus
50 * be careful to read the latest value from this function's return
51 * before doing any more work with it.
53 public JS putAndTriggerTraps(JS key, JS value) throws JSExn;
55 /** Gets the value for a given key, calling any read traps that have
56 * been placed on the key.
58 * This function may block for an indeterminate amount of time.
60 public JS getAndTriggerTraps(JS key) throws JSExn;
62 /** Calls the write traps placed on a given key with the given value
63 * and returns the result without saving it to this object's key store. */
64 public JS justTriggerTraps(JS key, JS value) throws JSExn;
66 public void addTrap(JS key, JS function) throws JSExn;
67 public void delTrap(JS key, JS function) throws JSExn;
68 public Trap getTrap(JS key) throws JSExn;
70 // FIXME: consider renaming/removing these
71 public InputStream getInputStream() throws IOException, JSExn;
73 public String coerceToString();
76 // Implementations ////////////////////////////////////////////////////////
78 /** Provides the lightest possible implementation of JS, throwing
79 * exceptions on every mutable operation. */
80 public static class Immutable implements JS {
81 private static final String[] emptystr = new String[0];
83 public JS unclone() { return this; }
84 public JS.Enumeration keys() throws JSExn { throw new JSExn(
85 "object has no key set, class ["+ getClass().getName() +"]"); }
86 public JS get(JS key) throws JSExn { return null; }
87 public void put(JS key, JS val) throws JSExn { throw new JSExn(
88 "'" + key + "' is read only on class ["+ getClass().getName() +"]"); }
89 public InputStream getInputStream() throws IOException, JSExn { throw new JSExn(
90 "object has not associated stream, class ["+ getClass().getName() +"]"); }
92 public Object run(Object o) throws Exception { throw new JSExn(
93 "object cannot be called, class ["+ getClass().getName() +"]"); }
94 public void pause() { throw new NotPausableException(); }
96 public JS call(JS[] args) throws JSExn { throw new JSExn( "object cannot be called, class ["+ getClass().getName() +"]"); }
97 public JS call(JS method, JS[] args) throws JSExn {
98 if (method == null) return call(args);
99 throw new JSExn("method not found: " + JSU.str(method) + " class="+this.getClass().getName());
101 public String[] getFormalArgs() { return emptystr; }
103 public void declare(JS key) throws JSExn { throw new JSExn(
104 "object cannot declare key: "+ JSU.str(key)); }
105 public void undeclare(JS key) throws JSExn { } // FIXME throw error?
107 public JS putAndTriggerTraps(JS key, JS val) throws JSExn { throw new JSExn(
108 "'" + key + "' is trap read only on class ["+ getClass().getName() +"]"); }
109 public JS getAndTriggerTraps(JS key) throws JSExn { return null; } // FIXME throw errors?
110 public JS justTriggerTraps(JS key, JS value) throws JSExn { return null; }
112 public void addTrap(JS key, JS function) throws JSExn {
113 Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]"); }
114 public void delTrap(JS key, JS function) throws JSExn {
115 Log.warn(this, "'" + JSU.str(key) + "' trap is read only on class ["+ getClass().getName() +"]"); }
116 public Trap getTrap(JS key) throws JSExn {
117 //Log.warn(this, "'" + JSU.str(key) + "' is not trappable on class ["+ getClass().getName() +"]");
121 public String coerceToString() { return "object"; }
124 public interface Cloneable {}
126 public static class Clone implements JS {
127 protected final JS clonee;
128 public Clone(JS clonee) throws JSExn {
129 if (!(clonee instanceof Cloneable)) throw new JSExn(
130 clonee.getClass().getName() + " is not implement cloneable");
131 this.clonee = clonee;
134 public JS unclone() { return clonee.unclone(); }
135 public boolean equals(Object o) { return clonee.equals(o); }
137 public Enumeration keys() throws JSExn { return clonee.keys(); }
138 public JS get(JS k) throws JSExn { return clonee.get(k); }
139 public void put(JS k, JS v) throws JSExn { clonee.put(k, v); }
140 public InputStream getInputStream() throws IOException, JSExn {
141 return clonee.getInputStream(); }
143 public Object run(Object o) throws Exception { return clonee.run(o); }
144 public void pause() { clonee.pause(); }
146 public JS call(JS m, JS[] a) throws JSExn { return clonee.call(m, a); }
147 public JS call(JS[] a) throws JSExn { return clonee.call(a); }
148 public String[] getFormalArgs() { return clonee.getFormalArgs(); }
150 public JS putAndTriggerTraps(JS k, JS v) throws JSExn {
151 return clonee.putAndTriggerTraps(k, v); }
152 public JS getAndTriggerTraps(JS k) throws JSExn {
153 return clonee.getAndTriggerTraps(k); }
154 public JS justTriggerTraps(JS k, JS v) throws JSExn {
155 return clonee.justTriggerTraps(k, v); }
157 public void addTrap(JS k, JS f) throws JSExn { clonee.addTrap(k, f); }
158 public void delTrap(JS k, JS f) throws JSExn { clonee.delTrap(k, f); }
159 public Trap getTrap(JS k) throws JSExn { return clonee.getTrap(k); }
161 public String coerceToString() { return clonee.coerceToString(); }
164 public static class Obj extends Basket.HashMap implements JS {
165 private static final String[] emptystr = new String[0];
166 private static final Placeholder holder = new Placeholder();
168 public Obj() { super(3, 4, 0.75F); }
170 public JS unclone() { return this; }
171 public InputStream getInputStream() throws IOException, JSExn { throw new JSExn(
172 "object has not associated stream, class ["+ getClass().getName() +"]"); }
174 public Object run(Object o) throws Exception { throw new JSExn(
175 "object cannot be called, class ["+ getClass().getName() +"]"); }
176 public void pause() { throw new NotPausableException(); }
178 public JS call(JS[] args) throws JSExn { throw new JSExn(
179 "object cannot be called, class ["+ getClass().getName() +"]"); }
180 public JS call(JS method, JS[] args) throws JSExn { throw new JSExn(
181 "method not found: " + JSU.str(method)); }
182 public String[] getFormalArgs() { return emptystr; }
184 public Enumeration keys() throws JSExn {
185 final Object[] keys = super.dumpkeys();
186 return new Enumeration(null) {
188 public boolean _hasNext() { return cur < keys.length; }
189 public JS _next() throws JSExn {
190 if (cur >= keys.length) throw new NoSuchElementException();
191 return (JS)keys[cur++];
196 public JS get(JS key) throws JSExn { return (JS)super.get(key, 0); }
197 public void put(JS key, JS val) throws JSExn { super.put(key, val, 0); }
199 /*public boolean hasValue(JS key, JS value) {
200 int i = indexOf(key); return i >= 0 && entries[i + 1] != null; }
201 public boolean hasTrap(JS key, JS trap) {
202 int i = indexOf(key); return i >= 0 && entries[i + 2] != null; }*/
204 public JS putAndTriggerTraps(JS key, JS val) throws JSExn {
205 Trap t = (Trap)super.get(key, 1);
206 if (t != null && (t = t.write()) != null)
207 val = (JS)new Interpreter(t, val, false).run(null);
208 put(key, val); // HACK: necessary for subclasses overriding put()
209 /*if (i < 0) i = put(i, key);
210 if (val == null) entries[i + 1] = holder;
211 else entries[i + 1] = val;*/
214 public JS getAndTriggerTraps(JS key) throws JSExn {
215 Trap t = (Trap)super.get(key, 1);
216 return t == null ? (JS)super.get(key) : (JS)new Interpreter(t, null, false).run(null);
218 public JS justTriggerTraps(JS key, JS val) throws JSExn {
219 Trap t = (Trap)super.get(key, 1);
220 if (t == null || (t = t.write()) == null) return val;
221 return (JS)new Interpreter(t, val, true).run(null);
224 public void addTrap(JS key, JS f) throws JSExn {
225 if (f.getFormalArgs() == null || f.getFormalArgs().length > 1) throw new JSExn(
226 "traps must take either one argument (write) or no arguments (read)");
227 for (Trap t = (Trap)super.get(key, 1); t != null; t = t.next())
228 if (t.function().equals(f)) return;
229 super.put(key, new TrapHolder(this, key, f, (Trap)super.get(key, 1)), 1);
232 public void delTrap(JS key, JS f) throws JSExn {
233 Trap t = (Trap)super.get(key, 1);
235 if (t.function().equals(f)) { super.put(key, t.next(), 2); return; }
236 for (; t.next() != null; t = t.next())
237 if (t.next().function().equals(f)) { ((TrapHolder)t).next = t.next().next(); return; }
240 public Trap getTrap(JS key) throws JSExn { return (Trap)super.get(key, 1); }
242 public String coerceToString() { return "object"; }
244 private static final class Placeholder implements Serializable {}
246 private static final class TrapHolder implements Trap {
247 private final JS target, key, function;
249 TrapHolder(JS t, JS k, JS f, Trap n) { target = t; key = k; function = f; next = n; }
251 public JS key() { return key; }
252 public JS target() { return target; }
253 public JS function() { return function; }
255 public boolean isReadTrap() {
256 return function.getFormalArgs() == null || function.getFormalArgs().length == 0; }
257 public boolean isWriteTrap() {
258 return function.getFormalArgs() != null && function.getFormalArgs().length != 0; }
260 public Trap next() { return next; }
261 public Trap nextRead() {
262 Trap t = next; while (t != null && t.isWriteTrap()) t = t.next(); return t; }
263 public Trap nextWrite() {
264 Trap t = next; while (t != null && t.isReadTrap()) t = t.next(); return t; }
265 public Trap read() { return isReadTrap() ? this : nextRead(); }
266 public Trap write() { return isWriteTrap() ? this : nextWrite(); }
270 public interface Trap {
273 public JS function();
274 public boolean isReadTrap();
275 public boolean isWriteTrap();
277 public Trap nextRead();
278 public Trap nextWrite();
280 public Trap read(); // FIXME reconsider these function names
284 /** An empty class used for instanceof matching the result of JS.get()
285 * to decide if the key is a method (to be called with JS.callMethod(). */
286 public static final class Method extends Immutable {}
289 public static abstract class Enumeration extends Immutable {
290 public static final Enumeration EMPTY = new Empty(null);
292 private final Enumeration parent;
294 public Enumeration(Enumeration parent) { this.parent = parent; }
296 protected abstract boolean _hasNext();
297 protected abstract JS _next() throws JSExn;
299 public final boolean hasNext() {
300 return _hasNext() || (parent != null ? parent.hasNext() : false); }
301 public final JS next() throws JSExn {
302 if (_hasNext()) return _next();
303 if (parent == null) throw new NoSuchElementException("reached end of set");
304 return parent.next();
307 public JS get(JS key) throws JSExn {
308 //#switch(JSU.str(key))
309 case "hasNext": return JSU.B(hasNext());
310 case "next": return next();
312 return super.get(key);
315 public static final class Empty extends Enumeration {
316 public Empty(Enumeration parent) { super(parent); }
317 protected boolean _hasNext() { return false; }
318 protected JS _next() { throw new NoSuchElementException(); }
321 public static final class JavaIterator extends Enumeration {
322 private final Iterator i;
323 public JavaIterator(Enumeration parent, Iterator i) { super(parent); this.i = i; }
324 protected boolean _hasNext() { return i.hasNext(); }
325 protected JS _next() { return (JS)i.next(); }
328 public static final class RandomAccessList extends Enumeration {
329 private final List l;
330 private int pos = 0, size;
331 public RandomAccessList(Enumeration parent, List list) {
332 super(parent); l = list; size = l.size(); }
333 protected boolean _hasNext() { return pos < size; }
334 protected JS _next() { return (JS)l.get(pos++); }