X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Usermode%2FLibraries%2Flibspiderscript.so_src%2Fexec_ast.c;h=33dbea45cb496660ef04f8a3b9c8d5ec7869cdb5;hb=fe313c1dda9bd0e062f5ce88c3d990199799aa1b;hp=90045bca6027cc6bd63423a6c82b4f12ed73c763;hpb=efa38e0d56b1b620b6f4e5c4f91abc483a3065e2;p=tpg%2Facess2.git

diff --git a/Usermode/Libraries/libspiderscript.so_src/exec_ast.c b/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
index 90045bca..33dbea45 100644
--- a/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
+++ b/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
@@ -5,41 +5,60 @@
 #include <string.h>
 #include "ast.h"
 
-#define ERRPTR	((void*)((intptr_t)0-1))
-
 // === PROTOTYPES ===
-void	Object_Dereference(tSpiderVariable *Object);
-void	Object_Reference(tSpiderVariable *Object);
-tSpiderVariable	*Object_CreateInteger(uint64_t Value);
-tSpiderVariable	*Object_CreateReal(double Value);
-tSpiderVariable	*Object_CreateString(int Length, const char *Data);
-tSpiderVariable	*Object_CastTo(int Type, tSpiderVariable *Source);
- int	Object_IsTrue(tSpiderVariable *Value);
+void	Object_Dereference(tSpiderValue *Object);
+void	Object_Reference(tSpiderValue *Object);
+tSpiderValue	*SpiderScript_CreateInteger(uint64_t Value);
+tSpiderValue	*SpiderScript_CreateReal(double Value);
+tSpiderValue	*SpiderScript_CreateString(int Length, const char *Data);
+tSpiderValue	*SpiderScript_CastValueTo(int Type, tSpiderValue *Source);
+ int	SpiderScript_IsValueTrue(tSpiderValue *Value);
+char	*SpiderScript_DumpValue(tSpiderValue *Value);
+
+tSpiderValue	*AST_ExecuteNode(tAST_BlockState *Block, tAST_Node *Node);
 
-void	Variable_SetValue(tSpiderScript *Script, const char *Name, tSpiderVariable *Value);
-tSpiderVariable	*Variable_GetValue(tSpiderScript *Script, const char *Name);
+tAST_Variable *Variable_Define(tAST_BlockState *Block, int Type, const char *Name);
+ int	Variable_SetValue(tAST_BlockState *Block, const char *Name, tSpiderValue *Value);
+tSpiderValue	*Variable_GetValue(tAST_BlockState *Block, const char *Name);
+void	Variable_Destroy(tAST_Variable *Variable);
 
 // === CODE ===
 /**
  * \brief Dereference a created object
  */
-void Object_Dereference(tSpiderVariable *Object)
+void Object_Dereference(tSpiderValue *Object)
 {
+	if(!Object)	return ;
+	if(Object == ERRPTR)	return ;
 	Object->ReferenceCount --;
-	if( Object->ReferenceCount == 0 )	free(Object);
+	if( Object->ReferenceCount == 0 ) {
+		switch( (enum eSpiderScript_DataTypes) Object->Type )
+		{
+		case SS_DATATYPE_OBJECT:
+			Object->Object->Type->Destructor( Object->Object );
+			break;
+		case SS_DATATYPE_OPAQUE:
+			Object->Opaque.Destroy( Object->Opaque.Data );
+			break;
+		default:
+			break;
+		}
+		free(Object);
+	}
 }
 
-void Object_Reference(tSpiderVariable *Object)
+void Object_Reference(tSpiderValue *Object)
 {
+	if(!Object)	return ;
 	Object->ReferenceCount ++;
 }
 
 /**
  * \brief Create an integer object
  */
-tSpiderVariable	*Object_CreateInteger(uint64_t Value)
+tSpiderValue *SpiderScript_CreateInteger(uint64_t Value)
 {
-	tSpiderVariable	*ret = malloc( sizeof(tSpiderVariable) );
+	tSpiderValue	*ret = malloc( sizeof(tSpiderValue) );
 	ret->Type = SS_DATATYPE_INTEGER;
 	ret->ReferenceCount = 1;
 	ret->Integer = Value;
@@ -49,9 +68,9 @@ tSpiderVariable	*Object_CreateInteger(uint64_t Value)
 /**
  * \brief Create an real number object
  */
-tSpiderVariable	*Object_CreateReal(double Value)
+tSpiderValue *SpiderScript_CreateReal(double Value)
 {
-	tSpiderVariable	*ret = malloc( sizeof(tSpiderVariable) );
+	tSpiderValue	*ret = malloc( sizeof(tSpiderValue) );
 	ret->Type = SS_DATATYPE_REAL;
 	ret->ReferenceCount = 1;
 	ret->Real = Value;
@@ -61,9 +80,9 @@ tSpiderVariable	*Object_CreateReal(double Value)
 /**
  * \brief Create an string object
  */
-tSpiderVariable	*Object_CreateString(int Length, const char *Data)
+tSpiderValue *SpiderScript_CreateString(int Length, const char *Data)
 {
-	tSpiderVariable	*ret = malloc( sizeof(tSpiderVariable) + Length + 1 );
+	tSpiderValue	*ret = malloc( sizeof(tSpiderValue) + Length + 1 );
 	ret->Type = SS_DATATYPE_STRING;
 	ret->ReferenceCount = 1;
 	ret->String.Length = Length;
@@ -73,26 +92,58 @@ tSpiderVariable	*Object_CreateString(int Length, const char *Data)
 }
 
 /**
+ * \brief Concatenate two strings
  */
-tSpiderVariable	*Object_CastTo(int Type, tSpiderVariable *Source)
+tSpiderValue *Object_StringConcat(tSpiderValue *Str1, tSpiderValue *Str2)
 {
-	tSpiderVariable	*ret;
+	 int	newLen = 0;
+	tSpiderValue	*ret;
+	if(Str1)	newLen += Str1->String.Length;
+	if(Str2)	newLen += Str2->String.Length;
+	ret = malloc( sizeof(tSpiderValue) + newLen + 1 );
+	ret->Type = SS_DATATYPE_STRING;
+	ret->ReferenceCount = 1;
+	ret->String.Length = newLen;
+	if(Str1)
+		memcpy(ret->String.Data, Str1->String.Data, Str1->String.Length);
+	if(Str2) {
+		if(Str1)
+			memcpy(ret->String.Data+Str1->String.Length, Str2->String.Data, Str2->String.Length);
+		else
+			memcpy(ret->String.Data, Str2->String.Data, Str2->String.Length);
+	}
+	ret->String.Data[ newLen ] = '\0';
+	return ret;
+}
+
+/**
+ * \brief Cast one object to another
+ * \brief Type	Destination type
+ * \brief Source	Input data
+ */
+tSpiderValue *SpiderScript_CastValueTo(int Type, tSpiderValue *Source)
+{
+	tSpiderValue	*ret = ERRPTR;
+	 int	len = 0;
+
+	if( !Source )	return NULL;
+	
 	// Check if anything needs to be done
 	if( Source->Type == Type ) {
 		Object_Reference(Source);
 		return Source;
 	}
 	
-	switch(Type)
+	switch( (enum eSpiderScript_DataTypes)Type )
 	{
 	case SS_DATATYPE_UNDEF:
-	case SS_DATATYPE_NULL:
 	case SS_DATATYPE_ARRAY:
-		fprintf(stderr, "Object_CastTo - Invalid cast to %i\n", Type);
+	case SS_DATATYPE_OPAQUE:
+		fprintf(stderr, "SpiderScript_CastValueTo - Invalid cast to %i\n", Type);
 		return ERRPTR;
 	
 	case SS_DATATYPE_INTEGER:
-		ret = malloc(sizeof(tSpiderVariable));
+		ret = malloc(sizeof(tSpiderValue));
 		ret->Type = SS_DATATYPE_INTEGER;
 		ret->ReferenceCount = 1;
 		switch(Source->Type)
@@ -101,10 +152,39 @@ tSpiderVariable	*Object_CastTo(int Type, tSpiderVariable *Source)
 		case SS_DATATYPE_STRING:	ret->Integer = atoi(Source->String.Data);	break;
 		case SS_DATATYPE_REAL:	ret->Integer = Source->Real;	break;
 		default:
-			fprintf(stderr, "Object_CastTo - Invalid cast from %i\n", Source->Type);
+			fprintf(stderr, "SpiderScript_CastValueTo - Invalid cast from %i\n", Source->Type);
+			free(ret);
+			ret = ERRPTR;
+			break;
+		}
+		break;
+	
+	case SS_DATATYPE_STRING:
+		switch(Source->Type)
+		{
+		case SS_DATATYPE_INTEGER:	len = snprintf(NULL, 0, "%li", Source->Integer);	break;
+		case SS_DATATYPE_REAL:	snprintf(NULL, 0, "%f", Source->Real);	break;
+		default:	break;
+		}
+		ret = malloc(sizeof(tSpiderValue) + len + 1);
+		ret->Type = SS_DATATYPE_STRING;
+		ret->ReferenceCount = 1;
+		ret->String.Length = len;
+		switch(Source->Type)
+		{
+		case SS_DATATYPE_INTEGER:	sprintf(ret->String.Data, "%li", Source->Integer);	break;
+		case SS_DATATYPE_REAL:	sprintf(ret->String.Data, "%f", Source->Real);	break;
+		default:
+			fprintf(stderr, "SpiderScript_CastValueTo - Invalid cast from %i\n", Source->Type);
+			free(ret);
+			ret = ERRPTR;
 			break;
 		}
 		break;
+	
+	default:
+		fprintf(stderr, "BUG REPORT: Unimplemented cast target\n");
+		break;
 	}
 	
 	return ret;
@@ -113,12 +193,14 @@ tSpiderVariable	*Object_CastTo(int Type, tSpiderVariable *Source)
 /**
  * \brief Condenses a value down to a boolean
  */
-int Object_IsTrue(tSpiderVariable *Value)
+int SpiderScript_IsValueTrue(tSpiderValue *Value)
 {
-	switch(Value->Type)
+	if( Value == ERRPTR )	return 0;
+	if( Value == NULL )	return 0;
+	
+	switch( (enum eSpiderScript_DataTypes)Value->Type )
 	{
 	case SS_DATATYPE_UNDEF:
-	case SS_DATATYPE_NULL:
 		return 0;
 	
 	case SS_DATATYPE_INTEGER:
@@ -133,39 +215,117 @@ int Object_IsTrue(tSpiderVariable *Value)
 	case SS_DATATYPE_OBJECT:
 		return Value->Object != NULL;
 	
+	case SS_DATATYPE_OPAQUE:
+		return Value->Opaque.Data != NULL;
+	
 	case SS_DATATYPE_ARRAY:
 		return Value->Array.Length > 0;
+	default:
+		fprintf(stderr, "Spiderscript internal error: Unknown type %i in SpiderScript_IsValueTrue\n", Value->Type);
+		return 0;
 	}
 	return 0;
 }
 
-tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
+/**
+ * \brief Dump a value into a string
+ * \return Heap string
+ */
+char *SpiderScript_DumpValue(tSpiderValue *Value)
+{
+	char	*ret;
+	if( Value == ERRPTR )
+		return strdup("ERRPTR");
+	if( Value == NULL )
+		return strdup("null");
+	
+	switch( (enum eSpiderScript_DataTypes)Value->Type )
+	{
+	case SS_DATATYPE_UNDEF:	return strdup("undefined");
+	
+	case SS_DATATYPE_INTEGER:
+		ret = malloc( sizeof(Value->Integer)*2 + 3 );
+		sprintf(ret, "0x%lx", Value->Integer);
+		return ret;
+	
+	case SS_DATATYPE_REAL:
+		ret = malloc( sprintf(NULL, "%f", Value->Real) + 1 );
+		sprintf(ret, "%f", Value->Real);
+		return ret;
+	
+	case SS_DATATYPE_STRING:
+		ret = malloc( Value->String.Length + 3 );
+		ret[0] = '"';
+		strcpy(ret+1, Value->String.Data);
+		ret[Value->String.Length+1] = '"';
+		ret[Value->String.Length+2] = '\0';
+		return ret;
+	
+	case SS_DATATYPE_OBJECT:
+		ret = malloc( sprintf(NULL, "{%s *%p}", Value->Object->Type->Name, Value->Object) + 1 );
+		sprintf(ret, "{%s *%p}", Value->Object->Type->Name, Value->Object);
+		return ret;
+	
+	case SS_DATATYPE_OPAQUE:
+		ret = malloc( sprintf(NULL, "*%p", Value->Opaque.Data) + 1 );
+		sprintf(ret, "*%p", Value->Opaque.Data);
+		return ret;
+	
+	case SS_DATATYPE_ARRAY:
+		return strdup("Array");
+	
+	default:
+		fprintf(stderr, "Spiderscript internal error: Unknown type %i in Object_Dump\n", Value->Type);
+		return NULL;
+	}
+	
+}
+
+/**
+ * \brief Execute an AST node and return its value
+ */
+tSpiderValue *AST_ExecuteNode(tAST_BlockState *Block, tAST_Node *Node)
 {
 	tAST_Node	*node;
-	tSpiderVariable	*ret, *tmpvar;
-	tSpiderVariable	*op1, *op2;	// Binary operations
+	tSpiderValue	*ret = NULL, *tmpobj;
+	tSpiderValue	*op1, *op2;	// Binary operations
 	 int	cmp;	// Used in comparisons
 	
 	switch(Node->Type)
 	{
 	// No Operation
-	case NODETYPE_NOP:	ret = NULL;	break ;
+	case NODETYPE_NOP:	ret = NULL;	break;
 	
 	// Code block
 	case NODETYPE_BLOCK:
-		ret = NULL;
-		for(node = Node->Block.FirstChild; node; node = node->NextSibling )
 		{
-			if(node->Type == NODETYPE_RETURN) {
-				ret = AST_ExecuteNode(Script, node);
-				break ;
+			tAST_BlockState	blockInfo;
+			blockInfo.FirstVar = NULL;
+			blockInfo.RetVal = NULL;
+			blockInfo.Parent = Block;
+			blockInfo.Script = Block->Script;
+			ret = NULL;
+			for(node = Node->Block.FirstChild; node && !blockInfo.RetVal; node = node->NextSibling )
+			{
+				tmpobj = AST_ExecuteNode(&blockInfo, node);
+				if(tmpobj == ERRPTR) {	// Error check
+					ret = ERRPTR;
+					break ;
+				}
+				if(tmpobj)	Object_Dereference(tmpobj);	// Free unused value
 			}
-			else {
-				tmpvar = AST_ExecuteNode(Script, node);
-				if(tmpvar == ERRPTR)	return ERRPTR;	// Error check
-				if(tmpvar)	Object_Dereference(tmpvar);	// Free unused value
+			// Clean up variables
+			while(blockInfo.FirstVar)
+			{
+				tAST_Variable	*nextVar = blockInfo.FirstVar->Next;
+				Variable_Destroy( blockInfo.FirstVar );
+				blockInfo.FirstVar = nextVar;
 			}
+			
+			if( blockInfo.RetVal )
+				Block->RetVal = blockInfo.RetVal;
 		}
+		
 		break;
 	
 	// Assignment
@@ -174,82 +334,189 @@ tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
 			fprintf(stderr, "Syntax error: LVALUE of assignment is not a variable\n");
 			return ERRPTR;
 		}
-		ret = AST_ExecuteNode(Script, Node->Assign.Value);
-		// TODO: Apply operation
-		Variable_SetValue( Script, Node->Assign.Dest->Variable.Name, ret );
+		ret = AST_ExecuteNode(Block, Node->Assign.Value);
+		if(ret != ERRPTR)
+		{
+			if( Variable_SetValue( Block, Node->Assign.Dest->Variable.Name, ret ) ) {
+				Object_Dereference( ret );
+				fprintf(stderr, "on line %i\n", Node->Line);
+				return ERRPTR;
+			}
+		}
 		break;
 	
+	// Function Call
 	case NODETYPE_FUNCTIONCALL:
-		// TODO: Find a function from the export list in variant
-		//SpiderScript_ExecuteMethod(Script, Node->FunctionCall.Name
-		ret = ERRPTR;
-		fprintf(stderr, "TODO: Implement function calls\n");
+		{
+			 int	nParams = 0;
+			for(node = Node->FunctionCall.FirstArg; node; node = node->NextSibling) {
+				nParams ++;
+			}
+			// Logical block (used to allocate `params`)
+			{
+				tSpiderValue	*params[nParams];
+				 int	i=0;
+				for(node = Node->FunctionCall.FirstArg; node; node = node->NextSibling) {
+					params[i] = AST_ExecuteNode(Block, node);
+					if( params[i] == ERRPTR ) {
+						while(i--)	Object_Dereference(params[i]);
+						ret = ERRPTR;
+						goto _return;
+					}
+					i ++;
+				}
+				
+				// Call the function (SpiderScript_ExecuteMethod does the
+				// required namespace handling)
+				ret = SpiderScript_ExecuteMethod(Block->Script, Node->FunctionCall.Name, nParams, params);
+				
+				// Dereference parameters
+				while(i--)	Object_Dereference(params[i]);
+				
+				// falls out
+			}
+		}
+		break;
+	
+	// Conditional
+	case NODETYPE_IF:
+		ret = AST_ExecuteNode(Block, Node->If.Condition);
+		if( SpiderScript_IsValueTrue(ret) ) {
+			AST_ExecuteNode(Block, Node->If.True);
+		}
+		else {
+			AST_ExecuteNode(Block, Node->If.False);
+		}
+		Object_Dereference(ret);
 		break;
 	
-	// Return's special handling happens elsewhere
+	// Loop
+	case NODETYPE_LOOP:
+		ret = AST_ExecuteNode(Block, Node->For.Init);
+		if( Node->For.bCheckAfter ) {
+			do {
+				Object_Dereference(ret);
+				ret = AST_ExecuteNode(Block, Node->For.Code);
+				Object_Dereference(ret);
+				ret = AST_ExecuteNode(Block, Node->For.Condition);
+			} while( SpiderScript_IsValueTrue(ret) );
+		}
+		else {
+			Object_Dereference(ret);
+			ret = AST_ExecuteNode(Block, Node->For.Condition);
+			while( SpiderScript_IsValueTrue(ret) ) {
+				Object_Dereference(ret);
+				ret = AST_ExecuteNode(Block, Node->For.Code);
+				Object_Dereference(ret);
+				ret = AST_ExecuteNode(Block, Node->For.Condition);
+			}
+			Object_Dereference(ret);
+		}
+		break;
+	
+	// Return
 	case NODETYPE_RETURN:
-		ret = AST_ExecuteNode(Script, Node->UniOp.Value);
+		ret = AST_ExecuteNode(Block, Node->UniOp.Value);
+		Block->RetVal = ret;	// Return value set
 		break;
 	
-	// Variable
-	case NODETYPE_VARIABLE:	ret = Variable_GetValue( Script, Node->Variable.Name );	break;
+	// Define a variable
+	case NODETYPE_DEFVAR:
+		ret = NULL;
+		if( Variable_Define(Block, Node->DefVar.DataType, Node->DefVar.Name) == ERRPTR )
+			ret = ERRPTR;
+		break;
 	
+	// Variable
+	case NODETYPE_VARIABLE:
+		ret = Variable_GetValue( Block, Node->Variable.Name );
+		break;
+
+	// Cast a value to another
+	case NODETYPE_CAST:
+		ret = SpiderScript_CastValueTo(
+			Node->Cast.DataType,
+			AST_ExecuteNode(Block, Node->Cast.Value)
+			);
+		break;
+
+	// Index into an array
+	case NODETYPE_INDEX:
+		fprintf(stderr, "TODO: Array indexing\n");
+		ret = ERRPTR;
+		break;
+
 	// TODO: Implement runtime constants
-	case NODETYPE_CONSTANT:	ret = ERRPTR;	break;
+	case NODETYPE_CONSTANT:
+		fprintf(stderr, "TODO: Runtime Constants\n");
+		ret = ERRPTR;
+		break;
 	// Constant Values
-	case NODETYPE_STRING:	ret = Object_CreateString( Node->String.Length, Node->String.Data );	break;
-	case NODETYPE_INTEGER:	ret = Object_CreateInteger( Node->Integer );	break;
-	case NODETYPE_REAL: 	ret = Object_CreateReal( Node->Real );	break;
+	case NODETYPE_STRING:	ret = SpiderScript_CreateString( Node->String.Length, Node->String.Data );	break;
+	case NODETYPE_INTEGER:	ret = SpiderScript_CreateInteger( Node->Integer );	break;
+	case NODETYPE_REAL: 	ret = SpiderScript_CreateReal( Node->Real );	break;
 	
 	// --- Operations ---
 	// Boolean Operations
 	case NODETYPE_LOGICALAND:	// Logical AND (&&)
 	case NODETYPE_LOGICALOR:	// Logical OR (||)
 	case NODETYPE_LOGICALXOR:	// Logical XOR (^^)
-		op1 = AST_ExecuteNode(Script, Node->BinOp.Left);
-		op2 = AST_ExecuteNode(Script, Node->BinOp.Right);
+		op1 = AST_ExecuteNode(Block, Node->BinOp.Left);
+		if(op1 == ERRPTR)	return ERRPTR;
+		op2 = AST_ExecuteNode(Block, Node->BinOp.Right);
+		if(op2 == ERRPTR) {
+			Object_Dereference(op1);
+			return ERRPTR;
+		}
+		
 		switch( Node->Type )
 		{
 		case NODETYPE_LOGICALAND:
-			ret = Object_CreateInteger( Object_IsTrue(op1) && Object_IsTrue(op2) );
+			ret = SpiderScript_CreateInteger( SpiderScript_IsValueTrue(op1) && SpiderScript_IsValueTrue(op2) );
 			break;
 		case NODETYPE_LOGICALOR:
-			ret = Object_CreateInteger( Object_IsTrue(op1) || Object_IsTrue(op2) );
+			ret = SpiderScript_CreateInteger( SpiderScript_IsValueTrue(op1) || SpiderScript_IsValueTrue(op2) );
 			break;
 		case NODETYPE_LOGICALXOR:
-			ret = Object_CreateInteger( Object_IsTrue(op1) ^ Object_IsTrue(op2) );
+			ret = SpiderScript_CreateInteger( SpiderScript_IsValueTrue(op1) ^ SpiderScript_IsValueTrue(op2) );
 			break;
 		default:	break;
 		}
+		
+		// Free intermediate objects
+		Object_Dereference(op1);
+		Object_Dereference(op2);
 		break;
 	
 	// Comparisons
 	case NODETYPE_EQUALS:
 	case NODETYPE_LESSTHAN:
 	case NODETYPE_GREATERTHAN:
-		op1 = AST_ExecuteNode(Script, Node->BinOp.Left);
-		op2 = AST_ExecuteNode(Script, Node->BinOp.Right);
-		
-		// No conversion done for NULL
-		// TODO: Determine if this will ever be needed
-		if( op1->Type == SS_DATATYPE_NULL )
-		{
-			// NULLs always typecheck
-			ret = Object_CreateInteger(op2->Type == SS_DATATYPE_NULL);
-			break;
+		op1 = AST_ExecuteNode(Block, Node->BinOp.Left);
+		if(op1 == ERRPTR)	return ERRPTR;
+		op2 = AST_ExecuteNode(Block, Node->BinOp.Right);
+		if(op2 == ERRPTR) {
+			Object_Dereference(op1);
+			return ERRPTR;
 		}
 		
 		// Convert types
 		if( op1->Type != op2->Type ) {
 			// If dynamically typed, convert op2 to op1's type
-			if(Script->Variant->bDyamicTyped)
+			if(Block->Script->Variant->bDyamicTyped)
 			{
-				tmpvar = op2;
-				op2 = Object_CastTo(op1->Type, op2);
-				Object_Dereference(tmpvar);
+				tmpobj = op2;
+				op2 = SpiderScript_CastValueTo(op1->Type, op2);
+				Object_Dereference(tmpobj);
+				if(op2 == ERRPTR) {
+					Object_Dereference(op1);
+					return ERRPTR;
+				}
 			}
 			// If statically typed, this should never happen, but catch it anyway
 			else {
+				fprintf(stderr, "PARSER ERROR: Statically typed implicit cast (line %i)\n",
+					Node->Line);
 				ret = ERRPTR;
 				break;
 			}
@@ -257,8 +524,6 @@ tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
 		// Do operation
 		switch(op1->Type)
 		{
-		// - NULL
-		case SS_DATATYPE_NULL:	break;
 		// - String Compare (does a strcmp, well memcmp)
 		case SS_DATATYPE_STRING:
 			// Call memcmp to do most of the work
@@ -276,18 +541,26 @@ tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
 					cmp = -1;
 			}
 			break;
+		default:
+			fprintf(stderr, "SpiderScript internal error: TODO: Comparison of type %i\n", op1->Type);
+			ret = ERRPTR;
+			break;
 		}
 		
 		// Free intermediate objects
 		Object_Dereference(op1);
 		Object_Dereference(op2);
 		
+		// Error check
+		if( ret == ERRPTR )
+			break;
+		
 		// Create return
 		switch(Node->Type)
 		{
-		case NODETYPE_EQUALS:	ret = Object_CreateInteger(cmp == 0);	break;
-		case NODETYPE_LESSTHAN:	ret = Object_CreateInteger(cmp < 0);	break;
-		case NODETYPE_GREATERTHAN:	ret = Object_CreateInteger(cmp > 0);	break;
+		case NODETYPE_EQUALS:	ret = SpiderScript_CreateInteger(cmp == 0);	break;
+		case NODETYPE_LESSTHAN:	ret = SpiderScript_CreateInteger(cmp < 0);	break;
+		case NODETYPE_GREATERTHAN:	ret = SpiderScript_CreateInteger(cmp > 0);	break;
 		default:
 			fprintf(stderr, "SpiderScript internal error: Exec,CmpOp unknown op %i", Node->Type);
 			ret = ERRPTR;
@@ -308,61 +581,99 @@ tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
 	case NODETYPE_BITSHIFTRIGHT:
 	case NODETYPE_BITROTATELEFT:
 		// Get operands
-		op1 = AST_ExecuteNode(Script, Node->BinOp.Left);
-		op2 = AST_ExecuteNode(Script, Node->BinOp.Right);
+		op1 = AST_ExecuteNode(Block, Node->BinOp.Left);
+		if(op1 == ERRPTR)	return ERRPTR;
+		op2 = AST_ExecuteNode(Block, Node->BinOp.Right);
+		if(op2 == ERRPTR) {
+			Object_Dereference(op1);
+			return ERRPTR;
+		}
 		
 		// Convert types
-		if( op1->Type != op2->Type ) {
+		if( op1 && op2 && op1->Type != op2->Type ) {
 			// If dynamically typed, convert op2 to op1's type
-			if(Script->Variant->bDyamicTyped)
+			if(Block->Script->Variant->bDyamicTyped)
 			{
-				tmpvar = op2;
-				op2 = Object_CastTo(op1->Type, op2);
-				Object_Dereference(tmpvar);
+				tmpobj = op2;
+				op2 = SpiderScript_CastValueTo(op1->Type, op2);
+				Object_Dereference(tmpobj);
+				if(op2 == ERRPTR) {
+					Object_Dereference(op1);
+					return ERRPTR;
+				}
 			}
 			// If statically typed, this should never happen, but catch it anyway
 			else {
+				fprintf(stderr,
+					"PARSER ERROR: Statically typed implicit cast (from %i to %i)\n",
+					op2->Type, op1->Type
+					);
 				ret = ERRPTR;
 				break;
 			}
 		}
 		
+		// NULL Check
+		if( op1 == NULL || op2 == NULL ) {
+			ret = NULL;
+			break;
+		}
+		
 		// Do operation
 		switch(op1->Type)
 		{
-		case SS_DATATYPE_NULL:	break;
 		// String Concatenation
 		case SS_DATATYPE_STRING:
 			switch(Node->Type)
 			{
+			case NODETYPE_ADD:	// Concatenate
+				ret = Object_StringConcat(op1, op2);
+				break;
 			default:
-				fprintf(stderr, "SpiderScript internal error: Exec,BinOP,String unknown op %i", Node->Type);
+				fprintf(stderr, "SpiderScript internal error: Exec,BinOP,String unknown op %i\n", Node->Type);
 				ret = ERRPTR;
 				break;
 			}
 			break;
+		// Integer Operations
 		case SS_DATATYPE_INTEGER:
 			switch(Node->Type)
 			{
-			case NODETYPE_ADD:	ret = Object_CreateInteger( op1->Integer + op2->Integer );	break;
-			case NODETYPE_SUBTRACT:	ret = Object_CreateInteger( op1->Integer - op2->Integer );	break;
-			case NODETYPE_MULTIPLY:	ret = Object_CreateInteger( op1->Integer * op2->Integer );	break;
-			case NODETYPE_DIVIDE:	ret = Object_CreateInteger( op1->Integer / op2->Integer );	break;
-			case NODETYPE_MODULO:	ret = Object_CreateInteger( op1->Integer % op2->Integer );	break;
-			case NODETYPE_BWAND:	ret = Object_CreateInteger( op1->Integer & op2->Integer );	break;
-			case NODETYPE_BWOR: 	ret = Object_CreateInteger( op1->Integer | op2->Integer );	break;
-			case NODETYPE_BWXOR:	ret = Object_CreateInteger( op1->Integer ^ op2->Integer );	break;
-			case NODETYPE_BITSHIFTLEFT:	ret = Object_CreateInteger( op1->Integer << op2->Integer );	break;
-			case NODETYPE_BITSHIFTRIGHT:ret = Object_CreateInteger( op1->Integer >> op2->Integer );	break;
+			case NODETYPE_ADD:	ret = SpiderScript_CreateInteger( op1->Integer + op2->Integer );	break;
+			case NODETYPE_SUBTRACT:	ret = SpiderScript_CreateInteger( op1->Integer - op2->Integer );	break;
+			case NODETYPE_MULTIPLY:	ret = SpiderScript_CreateInteger( op1->Integer * op2->Integer );	break;
+			case NODETYPE_DIVIDE:	ret = SpiderScript_CreateInteger( op1->Integer / op2->Integer );	break;
+			case NODETYPE_MODULO:	ret = SpiderScript_CreateInteger( op1->Integer % op2->Integer );	break;
+			case NODETYPE_BWAND:	ret = SpiderScript_CreateInteger( op1->Integer & op2->Integer );	break;
+			case NODETYPE_BWOR: 	ret = SpiderScript_CreateInteger( op1->Integer | op2->Integer );	break;
+			case NODETYPE_BWXOR:	ret = SpiderScript_CreateInteger( op1->Integer ^ op2->Integer );	break;
+			case NODETYPE_BITSHIFTLEFT:	ret = SpiderScript_CreateInteger( op1->Integer << op2->Integer );	break;
+			case NODETYPE_BITSHIFTRIGHT:ret = SpiderScript_CreateInteger( op1->Integer >> op2->Integer );	break;
 			case NODETYPE_BITROTATELEFT:
-				ret = Object_CreateInteger( (op1->Integer << op2->Integer) | (op1->Integer >> (64-op2->Integer)) );
+				ret = SpiderScript_CreateInteger( (op1->Integer << op2->Integer) | (op1->Integer >> (64-op2->Integer)) );
 				break;
 			default:
-				fprintf(stderr, "SpiderScript internal error: Exec,BinOP,Integer unknown op %i", Node->Type);
+				fprintf(stderr, "SpiderScript internal error: Exec,BinOP,Integer unknown op %i\n", Node->Type);
 				ret = ERRPTR;
 				break;
 			}
 			break;
+		
+		// Real Numbers
+		case SS_DATATYPE_REAL:
+			switch(Node->Type)
+			{
+			default:
+				fprintf(stderr, "SpiderScript internal error: Exec,BinOP,Real unknown op %i\n", Node->Type);
+				ret = ERRPTR;
+				break;
+			}
+			break;
+		
+		default:
+			fprintf(stderr, "SpiderScript error: Invalid operation (%i) on type (%i)\n", Node->Type, op1->Type);
+			ret = ERRPTR;
+			break;
 		}
 		
 		// Free intermediate objects
@@ -375,5 +686,114 @@ tSpiderVariable *AST_ExecuteNode(tSpiderScript *Script, tAST_Node *Node)
 	//	fprintf(stderr, "ERROR: SpiderScript AST_ExecuteNode Unimplemented %i\n", Node->Type);
 	//	break;
 	}
+_return:
 	return ret;
 }
+
+/**
+ * \brief Define a variable
+ * \param Block	Current block state
+ * \param Type	Type of the variable
+ * \param Name	Name of the variable
+ * \return Boolean Failure
+ */
+tAST_Variable *Variable_Define(tAST_BlockState *Block, int Type, const char *Name)
+{
+	tAST_Variable	*var, *prev = NULL;
+	
+	for( var = Block->FirstVar; var; prev = var, var = var->Next )
+	{
+		if( strcmp(var->Name, Name) == 0 ) {
+			fprintf(stderr, "ERROR: Redefinition of variable '%s'\n", Name);
+			return ERRPTR;
+		}
+	}
+	
+	var = malloc( sizeof(tAST_Variable) + strlen(Name) + 1 );
+	var->Next = NULL;
+	var->Type = Type;
+	var->Object = NULL;
+	strcpy(var->Name, Name);
+	
+	if(prev)	prev->Next = var;
+	else	Block->FirstVar = var;
+	
+	//printf("Defined variable %s (%i)\n", Name, Type);
+	
+	return var;
+}
+
+/**
+ * \brief Set the value of a variable
+ * \return Boolean Failure
+ */
+int Variable_SetValue(tAST_BlockState *Block, const char *Name, tSpiderValue *Value)
+{
+	tAST_Variable	*var;
+	tAST_BlockState	*bs;
+	
+	for( bs = Block; bs; bs = bs->Parent )
+	{
+		for( var = bs->FirstVar; var; var = var->Next )
+		{
+			if( strcmp(var->Name, Name) == 0 ) {
+				if( !Block->Script->Variant->bDyamicTyped
+				 && (Value && var->Type != Value->Type) ) {
+					fprintf(stderr, "ERROR: Type mismatch assigning to '%s'\n", Name);
+					return -2;
+				}
+				Object_Reference(Value);
+				Object_Dereference(var->Object);
+				var->Object = Value;
+				return 0;
+			}
+		}
+	}
+	
+	if( Block->Script->Variant->bDyamicTyped )
+	{
+		// Define variable
+		var = Variable_Define(Block, Value->Type, Name);
+		Object_Reference(Value);
+		var->Object = Value;
+		return 0;
+	}
+	else
+	{
+		fprintf(stderr, "ERROR: Variable '%s' set while undefined\n", Name);
+		return -1;
+	}
+}
+
+/**
+ * \brief Get the value of a variable
+ */
+tSpiderValue *Variable_GetValue(tAST_BlockState *Block, const char *Name)
+{
+	tAST_Variable	*var;
+	tAST_BlockState	*bs;
+	
+	for( bs = Block; bs; bs = bs->Parent )
+	{
+		for( var = bs->FirstVar; var; var = var->Next )
+		{
+			if( strcmp(var->Name, Name) == 0 ) {
+				Object_Reference(var->Object);
+				return var->Object;
+			}
+		}
+	}
+	
+	fprintf(stderr, "ERROR: Variable '%s' used undefined\n", Name);
+	
+	return ERRPTR;
+}
+
+/**
+ * \brief Destorys a variable
+ */
+void Variable_Destroy(tAST_Variable *Variable)
+{
+	Object_Dereference(Variable->Object);
+	free(Variable);
+}