Partial implementation of metatables.

.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,12 @@
+#Sat Jun 16 07:29:29 PDT 2007
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.2
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.4
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=warning
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=warning
+org.eclipse.jdt.core.compiler.source=1.3

.settings/org.eclipse.jdt.ui.prefs

@@ -0,0 +1,3 @@
+#Sat Jun 16 07:29:29 PDT 2007
+eclipse.preferences.version=1
+internal.default.compliance=default

src/main/java/lua/Builtin.java

@@ -18,8 +18,10 @@ final class Builtin extends LFunction {
 
 	private static final int PRINT = 0;
 	private static final int PAIRS = 1;
+	private static final int GETMETATABLE = 2;
+	private static final int SETMETATABLE = 3;
 	
-	private static final String[] NAMES = { "print", "pairs" };
+	private static final String[] NAMES = { "print", "pairs", "getmetatable", "setmetatable" };
 	
 	private int id;
 	private Builtin( int id ) {			
@@ -31,7 +33,7 @@ final class Builtin extends LFunction {
 	}
 	
 	// perform a lua call
-	public void luaStackCall(StackState state, int base, int top) {
+	public void luaStackCall(StackState state, int base, int top, int nresults) {
 		switch ( id ) {
 		case PRINT:
 			for ( int i=base+1; i<top; i++ ) {
@@ -39,16 +41,26 @@ final class Builtin extends LFunction {
 				System.out.print( "\t" );
 			}
 			System.out.println();
-			state.adjustTop(base);
-			return;
+			state.top = base;
+			break;
 		case PAIRS:
 			LValue value = state.stack[base+1].luaPairs();
-			state.top = base+1;
 			state.stack[base] = value;
-			return;
+			state.top = base+1;
+			break;
+		case GETMETATABLE:
+			state.stack[base] = state.stack[base+1].luaGetMetatable();
+			state.top = base+1;
+			break;
+		case SETMETATABLE:
+			state.stack[base+1].luaSetMetatable(state.stack[base+2]);
+			state.top = base;
+			break;
 		default:
 			luaUnsupportedOperation();
 		}
+		if (nresults >= 0)
+			state.adjustTop(base + nresults);
 	}
 
 }

src/main/java/lua/io/Closure.java

@@ -16,7 +16,7 @@ public class Closure extends LValue {
 	}
 
 	// perform a lua call
-	public void luaStackCall(StackState state, int base, int top) {
+	public void luaStackCall(StackState state, int base, int top, int nresults) {
 		state.setupCall( this, base, top );
 	}
 

src/main/java/lua/value/LTable.java

@@ -2,13 +2,13 @@ package lua.value;
 
 import java.util.Enumeration;
 import java.util.Hashtable;
-import java.util.Vector;
 
 import lua.StackState;
 
 public class LTable extends LValue {
 	
 	private Hashtable m_hash = new Hashtable();
+	private LValue m_metatable;
 	
 	public LTable() {
 	}
@@ -34,6 +34,16 @@ public class LTable extends LValue {
 		return new LInteger( m_hash.size() );
 	}
 	
+	/** Valid for tables */
+	public LValue luaGetMetatable() {
+		return this.m_metatable;
+	}
+
+	/** Valid for tables */
+	public void luaSetMetatable(LValue metatable) {
+		this.m_metatable = metatable;
+	}
+	
 	/** Valid for tables */
 	public LValue luaPairs() {
 		Enumeration e = m_hash.keys();
@@ -51,15 +61,18 @@ public class LTable extends LValue {
 		}
 
 		// perform a lua call
-		public void luaStackCall(StackState state, int base, int top) {
+		public void luaStackCall(StackState state, int base, int top, int nresults) {
 			if ( e.hasMoreElements() ) {
 				LValue key = (LValue) e.nextElement();
-				state.adjustTop(base+2);
 				state.stack[base] = key;
 				state.stack[base+1] = t.luaGetTable(key);
+				state.top = base+2;
 			} else {
-				state.adjustTop(base);
+				state.stack[base] = LNil.NIL;
+				state.top = base+1;
 			}
+			if ( nresults >= 0 )
+				state.adjustTop(base + nresults);
 		}
 	}
 

src/main/java/lua/value/LValue.java

@@ -16,7 +16,7 @@ public class LValue {
 	}
 
 	// perform a lua call, return number of results actually produced
-	public void luaStackCall(StackState state, int base, int top) {
+	public void luaStackCall(StackState state, int base, int top, int nresults) {
 		luaUnsupportedOperation();
 	}
 
@@ -111,5 +111,15 @@ public class LValue {
 		return luaUnsupportedOperation();
 	}
 
+	/** Valid for tables */
+	public LValue luaGetMetatable() {
+		return luaUnsupportedOperation();
+	}
+
+	/** Valid for tables */
+	public void luaSetMetatable(LValue metatable) {
+		luaUnsupportedOperation();
+	}
+
 	
 }

src/test/java/LuacRunner.java

@@ -38,7 +38,7 @@ public class LuacRunner {
 		state.push( c );
 		for ( int i=0; i<args.length; i++ )
 			state.push( new LString(args[i]) );
-		state.docall(args.length, false);
+		state.docall(args.length, 0);
 
 		// print result? 
 		System.out.println("stack:");

src/test/res/compile.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 LUA_HOME=/cygdrive/c/programs/lua5.1
 TESTS="test1 test2 test3 test4 test5"
-TESTS="test5"
+TESTS="test6"
 for x in $TESTS
 do
     echo compiling $x

src/test/res/test6.lua

@@ -0,0 +1,44 @@
+t = { 11, 22, 33, you='one', me='two' }
+--[[
+for a,b in pairs(t) do
+	print( a, b )
+end
+print( "t[2]", t[2] )
+print( "t.me", t.me )
+print( "t.fred", t.fred )
+print( "t['me']", t["me"] )
+print( "t['fred']", t["fred"] )
+print( "me", me )
+print( "fred", fred )
+print( "t[me]", t[me] )
+print( "t[fred]", t[fred] )
+--]]
+
+-- basic metatable setting 
+t = { 11, 22, 33, you='one', me='two' }
+mt = { __index = print, __newindex = print }
+setmetatable(t,mt)
+a = t[11]
+b = t.one
+c = t[1]
+d = t.you
+t[4] = 'rat'
+t[1] = 'pipe'
+print( a, b, c, d )
+for a,b in pairs(t) do
+	print( a, b )
+end
+
+-- delegate to actual metatable
+s = { }
+mt = { __newindex = s, __index = _G }
+setmetatable(t, mt)
+print( t.you )
+x = 'wow'
+print( t.x )
+me = 'here'
+print( t.me )
+t[5] = 99
+for a,b in pairs(s) do
+	print( a, b )
+end