1 package edu.berkeley.sbp.misc;
2 import edu.berkeley.sbp.*;
3 import edu.berkeley.sbp.util.*;
6 import java.lang.reflect.*;
8 /** use of this class is not recommended; it can handle only S-attributed grammars */
9 public class ReflectiveWalker extends StringWalker {
10 public ReflectiveWalker() { this.target = this; }
11 public ReflectiveWalker(Object target) { this.target = target; }
12 private final Object target;
13 private String normalize(String s) {
14 StringBuffer ret = new StringBuffer();
15 for(int i=0; i<s.length(); i++) {
17 if (i==0 && c >= '0' && c <= '9') { ret.append('_'); ret.append(c); continue; }
19 case ' ': ret.append("_space_"); break;
20 case '~': ret.append("_tilde_"); break;
21 case ';': ret.append("_semicolon_"); break;
22 case '=': ret.append("_equals_"); break;
23 case '-': ret.append("_minus_"); break;
24 case ')': ret.append("_rightparen_"); break;
25 case '(': ret.append("_leftparen_"); break;
26 case '!': ret.append("_bang_"); break;
27 case '`': ret.append("_backtick_"); break;
28 case '\"': ret.append("_quotes_"); break;
29 case '\'': ret.append("_quote_"); break;
30 case ',': ret.append("_comma_"); break;
31 case '.': ret.append("_dot_"); break;
32 case '>': ret.append("_greater_"); break;
33 case '<': ret.append("_less_"); break;
34 case '&': ret.append("_amp_"); break;
35 case '@': ret.append("_at_"); break;
36 case '#': ret.append("_hash_"); break;
37 case '|': ret.append("_pipe_"); break;
38 case '^': ret.append("_caret_"); break;
39 case '%': ret.append("_percent_"); break;
40 case '$': ret.append("_dollar_"); break;
41 case ':': ret.append("_colon_"); break;
42 case '?': ret.append("_question_"); break;
43 case '/': ret.append("_slash_"); break;
44 case '\\': ret.append("_backslash_"); break;
45 case '*': ret.append("_star_"); break;
46 case '+': ret.append("_plus_"); break;
47 case '_': ret.append("_underscore_"); break;
48 case '[': ret.append("_leftbracket_"); break;
49 case ']': ret.append("_rightbracket_"); break;
50 case '{': ret.append("_leftbrace_"); break;
51 case '}': ret.append("_rightbrace_"); break;
52 default: ret.append(c); break;
55 return ret.toString();
58 public Object walk(Tree<String> tree) {
59 if (tree.head()!=null) {
60 Member m = member("$"+normalize(tree.head()), 0, false);
62 if ((m instanceof Method) && ((Method)m).getReturnType()==Void.TYPE) {
63 Reflection.fuzzyInvoke(target, m, new Object[0]);
67 return super.walk(tree);
70 public void walk(String tag) {
71 if (tag==null) return;
72 Member m = member(normalize(tag), 0, false);
73 if (m!=null) Reflection.fuzzyInvoke(target, m);
75 protected Object defaultWalk(String tag, Object[] argo) { return super.walk(tag, argo); }
76 public Object walk(String tag, Object[] argo) {
77 if (argo.length==0) return super.walk(tag, argo);
78 if (argo==null) return tag;
79 if (tag==null || "".equals(tag)) return argo;
80 Member m = tag==null ? null : member(normalize(tag), argo.length, false);
81 if (m==null) return defaultWalk(tag, argo);
82 //System.out.println("preparing to invoke method " + (m==null ? "null" : (m.toString())) + " for sequence " + (owner()+"."+tag));
83 if (m != null) return Reflection.fuzzyInvoke(target, m, argo);
84 if (argo.length==0) return null;
85 if (argo.length==1) return argo[0];
86 Class c = argo[0].getClass();
87 for(Object o : argo) c = Reflection.lub(c, o.getClass());
88 Object[] ret = Reflection.newArray(c, argo.length);
89 System.arraycopy(argo, 0, ret, 0, argo.length);
93 public Member member(String methodName, int nonVoid, boolean complain) {
94 Class target = this.target.getClass();
95 if (methodName == null || methodName.equals("")) return null;
97 for (Method m : target.getMethods()) {
98 if (!m.getName().equals(methodName)) continue;
99 if (m.getParameterTypes().length != nonVoid) continue;
101 if (!complain) return null;
102 throw new Error("two methods with " + nonVoid + " parameters: " + target.getName() + "." + methodName);
106 if (ret != null) return ret;
109 Class c = Reflection.forNameOrNull(t.getName() + "$" + methodName);
111 for (Constructor m : c.getConstructors()) {
112 if (m.getParameterTypes().length != nonVoid) continue;
114 if (!complain) return null;
115 throw new Error("two constructors with " + nonVoid + " parameters: " + c.getName() + ".<init>()");
119 if (ret != null) return ret;
121 t = t.getSuperclass();
123 if (ret != null) return ret;
124 if (!complain) return null;
125 throw new Error("while computing return type of " +methodName+ " could not find method with name " + methodName +
126 " and " + nonVoid + " arguments");