1 package edu.berkeley.sbp.misc;
4 import java.lang.reflect.*;
5 import edu.berkeley.sbp.*;
6 import edu.berkeley.sbp.misc.*;
7 import edu.berkeley.sbp.tib.*;
8 import edu.berkeley.sbp.chr.*;
9 import edu.berkeley.sbp.util.*;
11 public class ReflectiveGrammar /*extends MetaGrammar*/ {
13 final Class baseClass;
14 public ReflectiveGrammar(Class baseClass) { this.baseClass = baseClass; }
16 public Object convertLabel(String label) { return new ClassMark(label); }
17 public Object repeatTag() { return arrayMark; }
19 private static class ArrayMark { }
20 private static final ArrayMark arrayMark = new ArrayMark();
22 private static class ClassMark {
23 public final String clazz;
24 public ClassMark(String clazz) { this.clazz = clazz; }
25 public String toString() { return clazz+"$"; }
28 public String stringify(Tree<Object> t) throws Exception {
29 StringBuffer ret = new StringBuffer();
30 for(int i=0; i<t.numChildren(); i++) {
31 Tree<Object> child = t.child(i);
32 Object head = child.numChildren() > 0 ? buildHead(child, String.class) : child.head();
33 if (head!=null) ret.append(head);
35 return ret.toString();
38 public Object build(Tree<Object> t) throws Exception { return buildHead(t, null); }
39 public Object buildHead(Tree<Object> t, Class c) throws Exception {
40 //System.out.println("buildHead " + (c==null?null:c.getName()) + " " + t);
43 if (h != null && h instanceof ClassMark) {
44 String clazz = ReflectiveWalker.mangle(((ClassMark)h).clazz);
45 Class c2 = (c!=null && c.getName().endsWith("$"+clazz)) ? c : Reflection.forNameOrNull(baseClass.getName()+"$"+clazz);
46 if (c2!=null) return buildBody(t, c2);
47 for(Method m : baseClass.getMethods()) {
48 if (!m.getName().equals(clazz)) continue;
49 Object[] o = new Object[m.getParameterTypes().length];
50 for(int i=0; i<o.length; i++)
51 o[i] = i>=t.numChildren() ? null : buildHead(t.child(i), m.getParameterTypes()[i]);
52 return m.invoke(null, o);
54 throw new RuntimeException("couldn't figure out what to invoke for ClassMark " + clazz);
55 } else if (h==arrayMark && c==null) {
59 Object[] ret = new Object[t.numChildren()];
60 for(int i=0; i<ret.length; i++)
61 ret[i] = buildHead(t.child(i), c.getComponentType());
62 return Reflection.lub(ret);
64 if (c==String.class) return stringify(t);
65 if (c==int.class) { String s = stringify(t); if (s==null||"".equals(s)) return new Integer(0); return new Integer(s); }
66 if (h==null) return buildBody(t, c);
68 if (t.numChildren() > 0)
69 throw new RuntimeException("can't buildHead() on a tree with children when the head is of type " +
70 h.getClass().getName() + "(c=="+(c==null?"null":c.getName())+")");
74 public Object buildBody(Tree<Object> t, Class c) throws Exception {
75 //System.out.println("buildBody " + (c==null?null:c.getName()) + " " + t);
76 c = resolveClass(t, c);
77 if (c==null) return buildHead(t, null);
78 Object o = c.newInstance();
79 Field[] f = c.getFields();
80 OUTER: for(int i=0; i<t.numChildren(); i++) {
81 Object label = t.label(i);
83 if (label!=null) field = Reflection.getField(c, label+"");
84 if (field==null && label != null)
85 for(Method m : c.getMethods())
86 if (m.getName().equals(label)) {
87 m.invoke(o, new Object[] { buildHead(t.child(i), m.getParameterTypes()[0]) });
90 if (field==null && label==null) {
91 field = Reflection.getField(c, 0);
94 System.err.println("warning: skipping field " + label + " ("+i+") on class " + c.getName());
95 System.err.println(" tree: " + t);
98 Object tgt = Reflection.rebuild(buildHead(t.child(i), field.getType()), field.getType());
99 //if (tgt instanceof Object[]) tgt = Reflection.lub(tgt);
100 //System.err.println("setting field " + field.getName() + " on " + c.getName() + " to " + tgt);
103 } catch (Exception e) {
111 public Class resolveClass(Tree<Object> t, Class c) throws Exception {
112 if (c==null) return null;
113 if (c==int.class) return c;
114 if (c==String.class) return c;
115 //System.out.println("resolving " + c.getName());
116 if (Reflection.isConcrete(c)) return c;
118 Class[] subs = (Class[])c.getField("subclasses").get(null);
119 OUTER: for(int i=0; i<subs.length; i++) {
120 //System.err.println("trying " + subs[i].getName());
121 for(int j=0; j<t.numChildren(); j++)
122 if (Reflection.getField(subs[i], t.label(j)+"")==null) {
123 //System.err.println("skipping due to " + t.label(j));
127 throw new RuntimeException("couldn't decide between two classes:\n " + subs[i].getName() + "\n " + ret.getName());
130 if (t.head()==null) return null;
131 if (ret==null) throw new RuntimeException("couldn't find a class to match tree: " + t);