X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmisc%2FReflectiveWalker.java;h=f22f4b8583d00a9670874087043708a451e6d374;hp=2334d621f1c65e90fc4e487713b8e8ec95304939;hb=e4b4b7b0da38d93fc9160b0058a81c1fc7f6773b;hpb=0a0227b9180534d2a431f3d6e08a398bde2244c4

diff --git a/src/edu/berkeley/sbp/misc/ReflectiveWalker.java b/src/edu/berkeley/sbp/misc/ReflectiveWalker.java
index 2334d62..f22f4b8 100644
--- a/src/edu/berkeley/sbp/misc/ReflectiveWalker.java
+++ b/src/edu/berkeley/sbp/misc/ReflectiveWalker.java
@@ -5,6 +5,7 @@ import java.io.*;
 import java.util.*;
 import java.lang.reflect.*;
 
+/** use of this class is not recommended; it can handle only S-attributed grammars */
 public class ReflectiveWalker extends StringWalker {
     public ReflectiveWalker()              { this.target = this; }
     public ReflectiveWalker(Object target) { this.target = target; }
@@ -53,11 +54,25 @@ public class ReflectiveWalker extends StringWalker {
         }
         return ret.toString();
     }
+    /*
+    public Object walk(Tree<String> tree) {
+        if (tree.head()!=null) {
+            Member m = member("$"+normalize(tree.head()), 0, false);
+            if (m!=null) {
+                if ((m instanceof Method) && ((Method)m).getReturnType()==Void.TYPE) {
+                    Reflection.fuzzyInvoke(target, m, new Object[0]);
+                }
+            }
+        }
+        return super.walk(tree);
+    }
+    */
     public Object walk(String tag, Object[] argo) {
         if (argo.length==0) return super.walk(tag, argo);
         if (argo==null) return tag;
         if (tag==null || "".equals(tag)) return argo;
-        Member m = member(normalize(tag), argo.length);
+        Member m = member(normalize(tag), argo.length, argo.length>0);
+        if (m==null) return super.walk(tag, argo);
         //System.out.println("preparing to invoke method " + (m==null ? "null" : (m.toString())) + " for sequence " + (owner()+"."+tag));
         if (m != null) return Reflection.fuzzyInvoke(target, m, argo);
         if (argo.length==0) return null;
@@ -69,14 +84,17 @@ public class ReflectiveWalker extends StringWalker {
         return ret;
     }
 
-    public Member member(String methodName, int nonVoid) {
+    public Member member(String methodName, int nonVoid, boolean complain) {
         Class target = this.target.getClass();
         if (methodName == null || methodName.equals("")) return null;
         Member ret = null;
         for (Method m : target.getMethods()) {
             if (!m.getName().equals(methodName)) continue;
             if (m.getParameterTypes().length != nonVoid) continue;
-            if (ret != null) throw new Error("two methods with " + nonVoid + " parameters: " + target.getName() + "." + methodName);
+            if (ret != null) {
+                if (!complain) return null;
+                throw new Error("two methods with " + nonVoid + " parameters: " + target.getName() + "." + methodName);
+            }
             ret = m;
         }
         if (ret != null) return ret;
@@ -86,7 +104,10 @@ public class ReflectiveWalker extends StringWalker {
             if (c != null) {
                 for (Constructor m : c.getConstructors()) {
                     if (m.getParameterTypes().length != nonVoid) continue;
-                    if (ret != null) throw new Error("two constructors with " + nonVoid + " parameters: " + c.getName() + ".<init>()");
+                    if (ret != null) {
+                        if (!complain) return null;
+                        throw new Error("two constructors with " + nonVoid + " parameters: " + c.getName() + ".<init>()");
+                    }
                     ret = m;
                 }
                 if (ret != null) return ret;
@@ -94,6 +115,7 @@ public class ReflectiveWalker extends StringWalker {
             t = t.getSuperclass();
         }
         if (ret != null) return ret;
+        if (!complain) return null;
         throw new Error("while computing return type of " +methodName+ " could not find method with name " + methodName +
                         " and " + nonVoid + " arguments");
     }