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comparison src/luan/LuaState.java @ 40:e3624b7cd603

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implement stack trace git-svn-id: https://luan-java.googlecode.com/svn/trunk@41 21e917c8-12df-6dd8-5cb6-c86387c605b9
author fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
date Fri, 21 Dec 2012 10:45:54 +0000
parents 8a57ebfdfd78
children 786699c78837
comparison
equal deleted inserted replaced
39:e5bcb1eeafc1 40:e3624b7cd603
1 package luan; 1 package luan;
2 2
3 import java.util.List;
4 import java.util.ArrayList;
3 5
4 public interface LuaState { 6
5 public LuaTable global(); 7 public abstract class LuaState {
6 public String toString(Object obj) throws LuaException; 8 private final LuaTable global = new LuaTable();
7 public LuaTable getMetatable(Object obj); 9 private final List<MetatableGetter> mtGetters = new ArrayList<MetatableGetter>();
8 public void addMetatableGetter(MetatableGetter mg); 10 final List<StackTraceElement> stackTrace = new ArrayList<StackTraceElement>();
11
12 public final LuaTable global() {
13 return global;
14 }
15
16 public final LuaTable getMetatable(Object obj) {
17 if( obj instanceof LuaTable ) {
18 LuaTable table = (LuaTable)obj;
19 return table.getMetatable();
20 }
21 for( MetatableGetter mg : mtGetters ) {
22 LuaTable table = mg.getMetatable(obj);
23 if( table != null )
24 return table;
25 }
26 return null;
27 }
28
29 public final void addMetatableGetter(MetatableGetter mg) {
30 mtGetters.add(mg);
31 }
32
33 public Object[] call(LuaFunction fn,LuaElement calledFrom,String fnName,Object... args) throws LuaException {
34 stackTrace.add( new StackTraceElement(calledFrom,fnName) );
35 try {
36 return fn.call(this,args);
37 } finally {
38 stackTrace.remove(stackTrace.size()-1);
39 }
40 }
41
42 public final String checkString(LuaElement el,Object obj) throws LuaException {
43 String s = Lua.asString(obj);
44 if( s == null )
45 throw new LuaException( this, el, "attempt to use a " + Lua.type(obj) + " as a string" );
46 return s;
47 }
48
49 public final LuaNumber checkNumber(LuaElement el,Object obj) throws LuaException {
50 LuaNumber n = Lua.toNumber(obj);
51 if( n == null )
52 throw new LuaException( this, el, "attempt to perform arithmetic on a " + Lua.type(obj) + " value" );
53 return n;
54 }
55
56 public final LuaFunction checkFunction(LuaElement el,Object obj) throws LuaException {
57 if( obj instanceof LuaFunction )
58 return (LuaFunction)obj;
59 throw new LuaException( this, el, "attempt to call a " + Lua.type(obj) + " value" );
60 }
61
62 public final String toString(LuaElement el,Object obj) throws LuaException {
63 LuaFunction fn = getHandlerFunction(el,"__tostring",obj);
64 if( fn != null )
65 return checkString( el, Lua.first( call(fn,el,"__tostring",obj) ) );
66 if( obj == null )
67 return "nil";
68 return obj.toString();
69 }
70
71 public final LuaFunction getHandlerFunction(LuaElement el,String op,Object obj) throws LuaException {
72 Object f = getHandler(op,obj);
73 if( f == null )
74 return null;
75 return checkFunction(el,f);
76 }
77
78 public final Object getHandler(String op,Object obj) {
79 LuaTable t = getMetatable(obj);
80 return t==null ? null : t.get(op);
81 }
82
9 } 83 }