From: John Hodge <tpg@mutabah.net>
Date: Thu, 26 Aug 2010 03:56:21 +0000 (+0800)
Subject: Added if() statement (and internal support for for,while and do{}while())
X-Git-Tag: rel0.06~40
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;ds=sidebyside;h=ec6f426069129f0a3d207f743ecddceddb57db8e;p=tpg%2Facess2.git

Added if() statement (and internal support for for,while and do{}while())
- Also improved return behavior
---

diff --git a/Usermode/Libraries/libspiderscript.so_src/ast.c b/Usermode/Libraries/libspiderscript.so_src/ast.c
index 45b8176a..8df54697 100644
--- a/Usermode/Libraries/libspiderscript.so_src/ast.c
+++ b/Usermode/Libraries/libspiderscript.so_src/ast.c
@@ -71,6 +71,9 @@ void AST_SetFunctionCode(tAST_Function *Function, tAST_Node *Root)
 void AST_FreeNode(tAST_Node *Node)
 {
 	tAST_Node	*node;
+	
+	if(!Node)	return ;
+	
 	switch(Node->Type)
 	{
 	// Block of code
@@ -93,6 +96,21 @@ void AST_FreeNode(tAST_Node *Node)
 		}
 		break;
 	
+	// If node
+	case NODETYPE_IF:
+		AST_FreeNode(Node->If.Condition);
+		AST_FreeNode(Node->If.True);
+		AST_FreeNode(Node->If.False);
+		break;
+	
+	// Looping Construct (For loop node)
+	case NODETYPE_LOOP:
+		AST_FreeNode(Node->For.Init);
+		AST_FreeNode(Node->For.Condition);
+		AST_FreeNode(Node->For.Increment);
+		AST_FreeNode(Node->For.Code);
+		break;
+	
 	// Asignment
 	case NODETYPE_ASSIGN:
 		AST_FreeNode(Node->Assign.Dest);
@@ -191,6 +209,30 @@ void AST_AppendNode(tAST_Node *Parent, tAST_Node *Child)
 	}
 }
 
+tAST_Node *AST_NewIf(tAST_Node *Condition, tAST_Node *True, tAST_Node *False)
+{
+	tAST_Node	*ret = malloc( sizeof(tAST_Node) );
+	ret->NextSibling = NULL;
+	ret->Type = NODETYPE_IF;
+	ret->If.Condition = Condition;
+	ret->If.True = True;
+	ret->If.False = False;
+	return ret;
+}
+
+tAST_Node *AST_NewLoop(tAST_Node *Init, int bPostCheck, tAST_Node *Condition, tAST_Node *Increment, tAST_Node *Code)
+{
+	tAST_Node	*ret = malloc( sizeof(tAST_Node) );
+	ret->NextSibling = NULL;
+	ret->Type = NODETYPE_LOOP;
+	ret->For.Init = Init;
+	ret->For.bCheckAfter = !!bPostCheck;
+	ret->For.Condition = Condition;
+	ret->For.Increment = Increment;
+	ret->For.Code = Code;
+	return ret;
+}
+
 tAST_Node *AST_NewAssign(int Operation, tAST_Node *Dest, tAST_Node *Value)
 {
 	tAST_Node	*ret = malloc( sizeof(tAST_Node) );
diff --git a/Usermode/Libraries/libspiderscript.so_src/ast.h b/Usermode/Libraries/libspiderscript.so_src/ast.h
index 4fa98ca0..05ed68bf 100644
--- a/Usermode/Libraries/libspiderscript.so_src/ast.h
+++ b/Usermode/Libraries/libspiderscript.so_src/ast.h
@@ -34,6 +34,9 @@ enum eAST_NodeTypes
 	NODETYPE_ASSIGN,	//!< Variable assignment operator
 	NODETYPE_FUNCTIONCALL,	//!< Call a function
 	
+	NODETYPE_IF,	//!< Conditional
+	NODETYPE_LOOP,	//!< Looping Construct
+	
 	NODETYPE_INDEX,	//!< Index into an array
 	
 	NODETYPE_LOGICALAND,	//!< Logical AND operator
@@ -119,6 +122,20 @@ struct sAST_Node
 			char	Name[];
 		}	FunctionCall;
 		
+		struct {
+			tAST_Node	*Condition;
+			tAST_Node	*True;
+			tAST_Node	*False;
+		}	If;
+		
+		struct {
+			tAST_Node	*Init;
+			 int	bCheckAfter;
+			tAST_Node	*Condition;
+			tAST_Node	*Increment;
+			tAST_Node	*Code;
+		}	For;
+		
 		/**
 		 * \note Used for \a NODETYPE_VARIABLE and \a NODETYPE_CONSTANT
 		 */
@@ -153,6 +170,7 @@ struct sAST_BlockState
 	tAST_BlockState	*Parent;
 	tSpiderScript	*Script;	//!< Script
 	tAST_Variable	*FirstVar;	//!< First variable in the list
+	tSpiderValue	*RetVal;
 };
 
 struct sAST_Variable
@@ -180,6 +198,9 @@ extern void	AST_AppendFunctionCallArg(tAST_Node *Node, tAST_Node *Arg);
 
 extern tAST_Node	*AST_NewCodeBlock(void);
 extern void	AST_AppendNode(tAST_Node *Parent, tAST_Node *Child);
+
+extern tAST_Node	*AST_NewIf(tAST_Node *Condition, tAST_Node *True, tAST_Node *False);
+
 extern tAST_Node	*AST_NewAssign(int Operation, tAST_Node *Dest, tAST_Node *Value);
 extern tAST_Node	*AST_NewBinOp(int Operation, tAST_Node *Left, tAST_Node *Right);
 extern tAST_Node	*AST_NewUniOp(int Operation, tAST_Node *Value);
diff --git a/Usermode/Libraries/libspiderscript.so_src/exec_ast.c b/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
index 0421686f..b9186087 100644
--- a/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
+++ b/Usermode/Libraries/libspiderscript.so_src/exec_ast.c
@@ -166,6 +166,9 @@ tSpiderValue *Object_CastTo(int Type, tSpiderValue *Source)
  */
 int Object_IsTrue(tSpiderValue *Value)
 {
+	if( Value == ERRPTR )	return 0;
+	if( Value == NULL )	return 0;
+	
 	switch( (enum eSpiderScript_DataTypes)Value->Type )
 	{
 	case SS_DATATYPE_UNDEF:
@@ -216,23 +219,18 @@ tSpiderValue *AST_ExecuteNode(tAST_BlockState *Block, tAST_Node *Node)
 		{
 			tAST_BlockState	blockInfo;
 			blockInfo.FirstVar = NULL;
+			blockInfo.RetVal = NULL;
 			blockInfo.Parent = Block;
 			blockInfo.Script = Block->Script;
 			ret = NULL;
-			for(node = Node->Block.FirstChild; node; node = node->NextSibling )
+			for(node = Node->Block.FirstChild; node && !blockInfo.RetVal; node = node->NextSibling )
 			{
-				if(node->Type == NODETYPE_RETURN) {
-					ret = AST_ExecuteNode(&blockInfo, node);
+				tmpobj = AST_ExecuteNode(&blockInfo, node);
+				if(tmpobj == ERRPTR) {	// Error check
+					ret = ERRPTR;
 					break ;
 				}
-				else {
-					tmpobj = AST_ExecuteNode(&blockInfo, node);
-					if(tmpobj == ERRPTR) {	// Error check
-						ret = ERRPTR;
-						break ;
-					}
-					if(tmpobj)	Object_Dereference(tmpobj);	// Free unused value
-				}
+				if(tmpobj)	Object_Dereference(tmpobj);	// Free unused value
 			}
 			// Clean up variables
 			while(blockInfo.FirstVar)
@@ -241,6 +239,9 @@ tSpiderValue *AST_ExecuteNode(tAST_BlockState *Block, tAST_Node *Node)
 				Variable_Destroy( blockInfo.FirstVar );
 				blockInfo.FirstVar = nextVar;
 			}
+			
+			if( blockInfo.RetVal )
+				Block->RetVal = blockInfo.RetVal;
 		}
 		
 		break;
@@ -289,9 +290,46 @@ tSpiderValue *AST_ExecuteNode(tAST_BlockState *Block, tAST_Node *Node)
 		}
 		break;
 	
-	// Return's special handling happens elsewhere
+	// Conditional
+	case NODETYPE_IF:
+		ret = AST_ExecuteNode(Block, Node->If.Condition);
+		if( Object_IsTrue(ret) ) {
+			AST_ExecuteNode(Block, Node->If.True);
+		}
+		else {
+			AST_ExecuteNode(Block, Node->If.False);
+		}
+		Object_Dereference(ret);
+		break;
+	
+	// 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( Object_IsTrue(ret) );
+		}
+		else {
+			Object_Dereference(ret);
+			ret = AST_ExecuteNode(Block, Node->For.Condition);
+			while( Object_IsTrue(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(Block, Node->UniOp.Value);
+		Block->RetVal = ret;	// Return value set
 		break;
 	
 	// Define a variable
diff --git a/Usermode/Libraries/libspiderscript.so_src/main.c b/Usermode/Libraries/libspiderscript.so_src/main.c
index a6b1bde5..0c3cb072 100644
--- a/Usermode/Libraries/libspiderscript.so_src/main.c
+++ b/Usermode/Libraries/libspiderscript.so_src/main.c
@@ -107,7 +107,8 @@ tSpiderValue *SpiderScript_ExecuteMethod(tSpiderScript *Script,
 		// Execute!
 		if(fcn) {
 			tAST_BlockState	bs;
-			bs.FirstVar = NULL;	//< TODO: Parameters
+			bs.FirstVar = NULL;
+			bs.RetVal = NULL;
 			bs.Parent = NULL;
 			bs.Script = Script;
 			{
@@ -122,6 +123,8 @@ tSpiderValue *SpiderScript_ExecuteMethod(tSpiderScript *Script,
 				}
 			}
 			ret = AST_ExecuteNode(&bs, fcn->Code);
+			//Object_Dereference(ret);
+			ret = bs.RetVal;
 			bFound = 1;
 		}
 	}
diff --git a/Usermode/Libraries/libspiderscript.so_src/parse.c b/Usermode/Libraries/libspiderscript.so_src/parse.c
index 5622123e..b25dd212 100644
--- a/Usermode/Libraries/libspiderscript.so_src/parse.c
+++ b/Usermode/Libraries/libspiderscript.so_src/parse.c
@@ -36,6 +36,11 @@ tAST_Node	*Parse_GetIdent(tParser *Parser);
 
 void	SyntaxAssert(tParser *Parser, int Have, int Want);
 
+#define TODO(Parser, message...) do {\
+	fprintf(stderr, "TODO: "message);\
+	longjmp(Parser->JmpTarget, -1);\
+}while(0)
+
 // === CODE ===
 /**
  * \brief Parse a buffer into a syntax tree
@@ -64,12 +69,14 @@ tAST_Script	*Parse_Buffer(tSpiderVariant *Variant, char *Buffer)
 	ret = AST_NewScript();
 	mainCode = AST_NewCodeBlock();
 	
+	// Give us an error fallback
 	if( setjmp( parser.JmpTarget ) != 0 )
 	{
 		AST_FreeNode( mainCode );
 		return NULL;
 	}
 	
+	// Parse the file!
 	while(Parser->Token != TOK_EOF)
 	{
 		switch( GetToken(Parser) )
@@ -159,7 +166,12 @@ tAST_Script	*Parse_Buffer(tSpiderVariant *Variant, char *Buffer)
 tAST_Node *Parse_DoCodeBlock(tParser *Parser)
 {
 	tAST_Node	*ret;
-	SyntaxAssert(Parser, GetToken(Parser), TOK_BRACE_OPEN );
+	
+	// Check if we are being called for a one-liner
+	if( GetToken(Parser) != TOK_BRACE_OPEN ) {
+		PutBack(Parser);
+		return Parse_DoBlockLine(Parser);
+	}
 	
 	ret = AST_NewCodeBlock();
 	
@@ -191,8 +203,26 @@ tAST_Node *Parse_DoBlockLine(tParser *Parser)
 		break;
 	
 	// Control Statements
-	//case TOK_RWD_IF:
-	//	break;
+	case TOK_RWD_IF:
+		{
+		tAST_Node	*cond, *true, *false = NULL;
+		GetToken(Parser);	// eat the if
+		SyntaxAssert(Parser, GetToken(Parser), TOK_PAREN_OPEN);
+		cond = Parse_DoExpr0(Parser);	// Get condition
+		SyntaxAssert(Parser, GetToken(Parser), TOK_PAREN_CLOSE);
+		true = Parse_DoCodeBlock(Parser);
+		if( LookAhead(Parser) == TOK_RWD_ELSE ) {
+			GetToken(Parser);
+			false = Parse_DoCodeBlock(Parser);
+		}
+		ret = AST_NewIf(cond, true, false);
+		}
+		return ret;
+	case TOK_RWD_FOR:
+	case TOK_RWD_DO:
+	case TOK_RWD_WHILE:
+		TODO(Parser, "Implement if, for, do and while\n");
+		break;
 	
 	// Define Variables
 	case TOKEN_GROUP_TYPES: