2003/11/03 00:08:26

[org.ibex.core.git] / src / org / xwt / Trap.java

diff --git a/src/org/xwt/Trap.java b/src/org/xwt/Trap.java
index 2f436c4..f982ffa 100644 (file)
--- a/src/org/xwt/Trap.java
+++ b/src/org/xwt/Trap.java
@@ -16,6 +16,19 @@ public class Trap {
 
     // Static Data //////////////////////////////////////////////////////////////
 
+    private static JS.CompiledFunction cascadeHelper = null;
+    private static String cascadeHelperText =
+        "return function(q) { var ret = arguments.doTrap;" +
+        "if (ret != false && !arguments.didCascade) arguments.cascade = q; };";
+    static {
+        try {
+            cascadeHelper = JS.parse("cascadeHelper", 1, new StringReader(cascadeHelperText));
+            cascadeHelper = (JS.CompiledFunction)new JS.Thread(cascadeHelper).resume();
+        } catch (Exception e) {
+            Log.log(Trap.class, e);
+        }
+    }
+
     /** List of properties that cannot be trapped */
     private static final Hash PROHIBITED = new Hash(120, 3);
 
@@ -63,12 +76,7 @@ public class Trap {
             if (t.f == f) return;
         
         // actually place the trap
-        Trap t = new Trap();
-        t.next = (Trap)trapee.get(name, Trap.class);
-        trapee.put(name, Trap.class, t);
-        t.trapee = trapee;
-        t.name = name;
-        t.f = f;
+        trapee.put2(name, Trap.class, new Trap(trapee, name.toString(), f, (Trap)trapee.get(name, Trap.class)));
     }
 
 
@@ -80,66 +88,43 @@ public class Trap {
      */
     static void delTrap(Box trapee, Object name, JS.CompiledFunction f) {
         Trap t = (Trap)trapee.get(name, Trap.class);
-        if (t.f == f) {
-            trapee.put(name, Trap.class, t.next);
-            return;
-        }
+        if (t.f == f) { trapee.put2(name, Trap.class, t.next); return; }
         for(; t.next != null; t = t.next)
-            if (t.next.f == f) {
-                t.next = t.next.next;
-                return;
-            }
+            if (t.next.f == f) { t.next = t.next.next; return; }
         Log.logJS("warning: tried to remove a trap that had not been placed");
     }
 
 
     // Instance Methods //////////////////////////////////////////////////////////////////////////
 
-    private Trap() { }
+    private Trap(Box b, String n, JS.CompiledFunction f, Trap nx)
+    { trapee = b; name = n; this.f = f; this.next = nx; }
+
+    // Read Traps //////////////////////////////////////////////////////////////////////
 
     public Object perform() {
-        try {
-            if (f.getNumFormalArgs() > 0) return cascade();
-            JS.Thread.current().setTailCall(f, new TrapArgs(this));
-            return null;
-        } catch (Exception e) {
-            Log.log(this, "Exception thrown from within trap: " + e);
-            return null;
-        }
+        if (f.getNumFormalArgs() > 0) return cascade();
+        else return new JS.TailCall().set(f, new TrapArgs(this));
     }
 
-    private static JS.CompiledFunction cascadeHelper = null;
-    private static String cascadeHelperText =
-        "return function(q) { var ret = arguments.doTrap;" +
-        "if (ret != false && !arguments.didCascade) arguments.cascade = q; };";
-    static {
-        try {
-            cascadeHelper = JS.parse("cascadeHelper", 1, new StringReader(cascadeHelperText));
-            cascadeHelper = (JS.CompiledFunction)new JS.Thread(cascadeHelper).resume();
-        } catch (Exception e) {
-            Log.log(Trap.class, e);
-        }
+    public Object cascade() {
+        if (next != null) return next.perform();
+        else return trapee.get(name, true);
     }
 
-    public void perform(Object val) {
-        try {
-            if (f.getNumFormalArgs() == 0) cascade(val);
-            else JS.Thread.current().setTailCall(cascadeHelper, new TrapArgs(this, val));
-        } catch (Exception e) {
-            Log.log(this, "Exception thrown from within trap: " + e);
-            e.printStackTrace();
-        }
+    // Write Traps //////////////////////////////////////////////////////////////////////
+
+    public void perform(Object val, JS.TailCall tail) {
+        if (f.getNumFormalArgs() == 0) cascade(val, tail);
+        else tail.set(cascadeHelper, new TrapArgs(this, val));
     }
     
-    public Object cascade() {
-        if (next != null) { next.perform(); return null; }
-        return trapee.get(name, true);
+    public void cascade(Object val, JS.TailCall tail) {
+        if (next != null) next.perform(val, tail);
+        else trapee.put(name, val, tail, true);
     }
 
-    public void cascade(Object val) {
-        if (next != null) next.perform(val);
-        trapee.put(name, val, true);
-    }
+    // Args ///////////////////////////////////////////////////////////////////////////
 
     private static class TrapArgs extends JS.Array {
         private Trap t;
@@ -147,16 +132,16 @@ public class Trap {
         public TrapArgs(Trap t) { this.t = t; }
         public TrapArgs(Trap t, Object value) { this.t = t; addElement(value); }
         
-        public void put(Object key, Object val) {
-            if (key.equals("cascade")) { cascadeHappened = true; t.cascade(val); }
-            else super.put(key, val);
+        public void put(Object key, Object val, JS.TailCall tail) {
+            if (key.equals("cascade")) { cascadeHappened = true; t.cascade(val, tail); }
+            else super.put(key, val, (JS.TailCall)tail);
         }
 
         public Object get(Object key) {
             // common case
             if(!(key instanceof String)) return super.get(key);
             if (key.equals("trapee")) return t.trapee;
-            if (key.equals("doTrap")) { JS.Thread.current().setTailCall(t.f, this); return null; }
+            if (key.equals("doTrap")) return new JS.TailCall().set(t.f, this);
             if (key.equals("didCascade")) return cascadeHappened ? Boolean.TRUE : Boolean.FALSE;
             if (key.equals("trapname")) return t.name;
             if (key.equals("cascade")) return t.cascade();