Implement foreach(), foreachi()

src/core/org/luaj/lib/TableLib.java

@@ -36,6 +36,8 @@ public class TableLib extends LFunction {
 	public static final String[] NAMES = {
 		"table",
 		"concat",
+		"foreach",
+		"foreachi",
 		"getn",
 		"insert",
 		"maxn",
@@ -45,11 +47,13 @@ public class TableLib extends LFunction {
 	
 	private static final int INSTALL  = 0;
 	private static final int CONCAT   = 1;
-	private static final int GETN    = 2;
-	private static final int INSERT  = 3;
-	private static final int MAXN    = 4;
-	private static final int REMOVE  = 5;
-	private static final int SORT    = 6;
+	private static final int FOREACH  = 2;
+	private static final int FOREACHI = 3;
+	private static final int GETN     = 4;
+	private static final int INSERT   = 5;
+	private static final int MAXN     = 6;
+	private static final int REMOVE   = 7;
+	private static final int SORT     = 8;
 	
 	public static void install( LTable globals ) {
 		LTable table = new LTable();
@@ -117,6 +121,21 @@ public class TableLib extends LFunction {
 			break;
 		}
 		
+		/* table.getn (table)
+		 * 
+		 * Get length of table t.
+		 */ 
+		case FOREACH: 
+		case FOREACHI: 
+		{ 
+			LTable table = vm.totable(2);
+			LFunction function = vm.tojavafunction(3);
+			LValue result = table.foreach( vm, function, id==FOREACHI );
+			vm.resettop();
+			vm.pushlvalue( result );
+			break;
+		}
+		
 		/* table.getn (table)
 		 * 
 		 * Get length of table t.

src/core/org/luaj/vm/LTable.java

@@ -700,4 +700,45 @@ public class LTable extends LValue {
 		
 		return n + slot + 1;
 	}
+
+	
+	/**
+	 * Executes the given f over all elements of table. For each element, f is
+	 * called with the index and respective value as arguments. If f returns a
+	 * non-nil value, then the loop is broken, and this value is returned as the
+	 * final value of foreach.
+	 * 
+	 * @param vm
+	 * @param function
+	 * @param isforeachi is a table.foreachi() call, not a table.foreach() call
+	 * @return
+	 */
+	public LValue foreach(LuaState vm, LFunction function, boolean isforeachi) {
+		for ( int i = 0; i < m_vector.length; ++i ) {
+			if ( m_vector[ i ] != LNil.NIL ) {
+				if ( foreachitem( vm, function, LInteger.valueOf(i+1), m_vector[i] ) )
+					return vm.topointer(1);
+			}
+		}
+		
+		if ( (! isforeachi) && m_hashKeys != null ) {
+			for ( int i = 0; i < m_hashKeys.length; ++i ) {
+				if ( m_hashKeys[ i ] != null ) {
+					if ( foreachitem( vm, function, m_hashKeys[i], m_hashValues[i] ) )
+						return vm.topointer(1);
+				}
+			}
+		}
+		
+		return LNil.NIL;
+	}
+
+	private static boolean foreachitem(LuaState vm, LFunction f, LValue key, LValue value) {
+		vm.resettop();
+		vm.pushlvalue( f );
+		vm.pushlvalue( key );
+		vm.pushlvalue( value );
+		vm.call(2, 1);
+		return ! vm.isnil(1);
+	}
 }

src/test/res/table.lua

@@ -66,3 +66,36 @@ table.sort(t)
 print( table.concat(t,'-'), table.maxn(t), #t )
 table.sort(t,function(a,b) return b<a end)
 print( table.concat(t,'-'), table.maxn(t), #t )
+
+-- getn
+t0 = {}
+t1 = { 'one', 'two', 'three' }
+t2 = { a='aa', b='bb', c='cc' }
+t3 = { 'one', 'two', 'three', a='aa', b='bb', c='cc' }
+print( 'getn(t0)', pcall( table.getn, t0 ) ) 
+print( 'getn(t0)', pcall( table.getn, t1 ) ) 
+print( 'getn(t0)', pcall( table.getn, t2 ) ) 
+print( 'getn(t0)', pcall( table.getn, t3 ) ) 
+
+-- foreach
+function test( f, t, result, name ) 
+	status, value = pcall( f, t, function(...) 
+		print(name,...)
+		return result 
+	end )
+	print( name, 's,v', status, value )
+end
+function testall( f, t, name ) 
+	test( f, t, nil, name..'nil' )
+	test( f, t, false, name..'fls' )
+	test( f, t, 100, name..'100' )
+end
+testall( table.foreach, t0, 'table.foreach(t0)' )
+testall( table.foreach, t1, 'table.foreach(t1)' )
+testall( table.foreach, t2, 'table.foreach(t2)' )
+testall( table.foreach, t3, 'table.foreach(t3)' )
+testall( table.foreachi, t0, 'table.foreachi(t0)' )
+testall( table.foreachi, t1, 'table.foreachi(t1)' )
+testall( table.foreachi, t2, 'table.foreachi(t2)' )
+testall( table.foreachi, t3, 'table.foreachi(t3)' )
+