Mercurial > botc / changeset

--- a/src/Expression.cc	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Expression.cc	Sun Feb 09 14:56:58 2014 +0200
@@ -77,7 +77,6 @@
 
 	try
 	{
-		ScriptVariable* globalvar;
 		mLexer->MustGetNext();
 
 		if (mLexer->GetTokenType() == tkColon)
@@ -108,43 +107,29 @@
 			return op;
 		}
 
-		// Check constant
-		if (ConstantInfo* constant = mParser->FindConstant (GetTokenString()))
+		// Check global variable
+		// TODO: handle locals too when they're implemented
+		if (mLexer->GetTokenType() == tkDollarSign)
 		{
-			if (mType != constant->type)
-				Error ("constant `%1` is %2, expression requires %3\n",
-					constant->name, GetTypeName (constant->type),
-						GetTypeName (mType));
+			mLexer->MustGetNext (tkSymbol);
+			ScriptVariable* globalvar = FindGlobalVariable (GetTokenString());
 
-			switch (constant->type)
+			if (globalvar == null)
+				Error ("unknown variable %1", GetTokenString());
+
+			if (globalvar->writelevel == ScriptVariable::WRITE_Constexpr)
+				op->SetValue (globalvar->value);
+			else
 			{
-				case EBoolType:
-				case EIntType:
-					op->SetValue (constant->val.ToLong());
-					break;
-
-				case EStringType:
-					op->SetValue (GetStringTableIndex (constant->val));
-					break;
-
-				case EVoidType:
-				case EUnknownType:
-					break;
+				DataBuffer* buf = new DataBuffer (8);
+				buf->WriteDWord (dhPushGlobalVar);
+				buf->WriteDWord (globalvar->index);
+				op->SetBuffer (buf);
 			}
 
 			return op;
 		}
 
-		// Check global variable
-		if ((globalvar = FindGlobalVariable (GetTokenString())))
-		{
-			DataBuffer* buf = new DataBuffer (8);
-			buf->WriteDWord (dhPushGlobalVar);
-			buf->WriteDWord (globalvar->index);
-			op->SetBuffer (buf);
-			return op;
-		}
-
 		EToken tt;
 
 		// Check for literal

--- a/src/LexerScanner.cc	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/LexerScanner.cc	Sun Feb 09 14:56:58 2014 +0200
@@ -102,6 +102,7 @@
 	"state",
 	"switch",
 	"str",
+	"var",
 	"void",
 	"while",
 	"true",

--- a/src/Parser.cc	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Parser.cc	Sun Feb 09 14:56:58 2014 +0200
@@ -117,10 +117,8 @@
 				ParseOnEnterExit();
 				break;
 
-			case tkInt:
-			case tkStr:
-			case tkVoid:
-				ParseVariableDeclaration();
+			case tkVar:
+				ParseVar();
 				break;
 
 			case tkGoto:
@@ -171,10 +169,6 @@
 				ParseBlockEnd();
 				break;
 
-			case tkConst:
-				ParseConst();
-				break;
-
 			case tkEventdef:
 				ParseEventdef();
 				break;
@@ -328,9 +322,12 @@
 
 // ============================================================================
 //
-void BotscriptParser::ParseVariableDeclaration()
+void BotscriptParser::ParseVar()
 {
-	// For now, only globals are supported
+	const bool isconst = mLexer->GetNext (tkConst);
+	mLexer->MustGetAnyOf ({tkInt, tkStr, tkVoid});
+
+	// TODO
 	if (mCurrentMode != ETopLevelMode || mCurrentState.IsEmpty() == false)
 		Error ("variables must only be global for now");
 
@@ -341,12 +338,32 @@
 	mLexer->MustGetNext();
 	String varname = GetTokenString();
 
-	// Var name must not be a number
-	if (varname.IsNumeric())
-		Error ("variable name must not be a number");
+	if (varname[0] >= '0' && varname[0] <= '9')
+		Error ("variable name must not start with a number");
 
 	ScriptVariable* var = DeclareGlobalVariable (type, varname);
-	(void) var;
+
+	if (isconst == false)
+	{
+		var->writelevel = ScriptVariable::WRITE_Mutable;
+	}
+	else
+	{
+		mLexer->MustGetNext (tkAssign);
+		Expression expr (this, mLexer, type);
+
+		if (expr.GetResult()->IsConstexpr())
+		{
+			var->writelevel = ScriptVariable::WRITE_Constexpr;
+			var->value = expr.GetResult()->GetValue();
+		}
+		else
+		{
+			// TODO: might need a VM-wise oninit for this...
+			Error ("const variables must be constexpr for now");
+		}
+	}
+
 	mLexer->MustGetNext (tkSemicolon);
 }
 
@@ -799,49 +816,6 @@
 
 // ============================================================================
 //
-void BotscriptParser::ParseConst()
-{
-	ConstantInfo info;
-
-	// Get the type
-	mLexer->MustGetNext();
-	String typestring = GetTokenString();
-	info.type = GetTypeByName (typestring);
-
-	if (info.type == EUnknownType || info.type == EVoidType)
-		Error ("unknown type `%1` for constant", typestring);
-
-	mLexer->MustGetNext();
-	info.name = GetTokenString();
-
-	mLexer->MustGetNext (tkAssign);
-
-	switch (info.type)
-	{
-		case EBoolType:
-		case EIntType:
-		{
-			mLexer->MustGetNext (tkNumber);
-		} break;
-
-		case EStringType:
-		{
-			mLexer->MustGetNext (tkString);
-		} break;
-
-		case EUnknownType:
-		case EVoidType:
-			break;
-	}
-
-	info.val = mLexer->GetToken()->text;
-	mConstants << info;
-
-	mLexer->MustGetNext (tkSemicolon);
-}
-
-// ============================================================================
-//
 void BotscriptParser::ParseLabel()
 {
 	CheckNotToplevel();
@@ -970,7 +944,7 @@
 {
 	DataBuffer* r = new DataBuffer (64);
 
-	if (mCurrentMode == ETopLevelMode)
+	if (mCurrentMode == ETopLevelMode && comm->returnvalue == EVoidType)
 		Error ("command call at top level");
 
 	mLexer->MustGetNext (tkParenStart);
@@ -1135,6 +1109,11 @@
 //
 DataBuffer* BotscriptParser::ParseAssignment (ScriptVariable* var)
 {
+	if (var->writelevel != ScriptVariable::WRITE_Mutable)
+	{
+		Error ("cannot alter read-only variable $%1", var->name);
+	}
+
 	// Get an operator
 	EAssignmentOperator oper = ParseAssignmentOperator();
 	DataBuffer* retbuf = new DataBuffer;
@@ -1212,12 +1191,17 @@
 //
 DataBuffer* BotscriptParser::ParseStatement()
 {
-	if (FindConstant (GetTokenString())) // There should not be constants here.
-		Error ("invalid use for constant\n");
+	// If it's a variable, expect assignment.
+	if (TokenIs (tkDollarSign))
+	{
+		mLexer->MustGetNext (tkSymbol);
+		ScriptVariable* var = FindGlobalVariable (GetTokenString());
 
-	// If it's a variable, expect assignment.
-	if (ScriptVariable* var = FindGlobalVariable (GetTokenString()))
+		if (var == null)
+			Error ("unknown variable $%1", var->name);
+
 		return ParseAssignment (var);
+	}
 
 	return null;
 }
@@ -1249,17 +1233,6 @@
 
 // ============================================================================
 //
-ConstantInfo* BotscriptParser::FindConstant (const String& tok)
-{
-	for (int i = 0; i < mConstants.Size(); i++)
-		if (mConstants[i].name == tok)
-			return &mConstants[i];
-
-	return null;
-}
-
-// ============================================================================
-//
 bool BotscriptParser::TokenIs (EToken a)
 {
 	return (mLexer->GetTokenType() == a);

--- a/src/Parser.h	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Parser.h	Sun Feb 09 14:56:58 2014 +0200
@@ -116,15 +116,6 @@
 
 // ============================================================================
 //
-struct ConstantInfo
-{
-	String name;
-	EType type;
-	String val;
-};
-
-// ============================================================================
-//
 class BotscriptParser
 {
 	PROPERTY (public, bool, ReadOnly, BOOL_OPS, STOCK_WRITE)
@@ -138,7 +129,6 @@
 
 		BotscriptParser();
 		~BotscriptParser();
-		ConstantInfo*			FindConstant (const String& tok);
 		void					ParseBotscript (String fileName);
 		DataBuffer*				ParseCommand (CommandInfo* comm);
 		DataBuffer*				ParseAssignment (ScriptVariable* var);
@@ -192,7 +182,6 @@
 		DataBuffer*				mIfExpression;
 		bool					mCanElse;
 		List<UndefinedLabel>	mUndefinedLabels;
-		List<ConstantInfo>		mConstants;
 
 		// How many bytes have we written to file?
 		int						mNumWrittenBytes;
@@ -205,7 +194,7 @@
 		void			ParseEventBlock();
 		void			ParseMainloop();
 		void			ParseOnEnterExit();
-		void			ParseVariableDeclaration();
+		void			ParseVar();
 		void			ParseGoto();
 		void			ParseIf();
 		void			ParseElse();
@@ -218,7 +207,6 @@
 		void			ParseBreak();
 		void			ParseContinue();
 		void			ParseBlockEnd();
-		void			ParseConst();
 		void			ParseLabel();
 		void			ParseEventdef();
 		void			ParseFuncdef();

--- a/src/Tokens.h	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Tokens.h	Sun Feb 09 14:56:58 2014 +0200
@@ -104,6 +104,7 @@
 	tkState,
 	tkSwitch,
 	tkStr,
+	tkVar,
 	tkVoid,
 	tkWhile,
 	tkTrue,

--- a/src/Variables.cc	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Variables.cc	Sun Feb 09 14:56:58 2014 +0200
@@ -60,7 +60,6 @@
 	g.index = g_GlobalVariables.Size();
 	g.name = name;
 	g.statename = "";
-	g.value = 0;
 	g.type = type;
 
 	g_GlobalVariables << g;

--- a/src/Variables.h	Sun Feb 09 14:34:13 2014 +0200
+++ b/src/Variables.h	Sun Feb 09 14:56:58 2014 +0200
@@ -31,15 +31,24 @@
 
 #include "Main.h"
 
+class ExpressionValue;
 class BotscriptParser;
 
 struct ScriptVariable
 {
-	String	name;
-	String	statename;
-	EType	type;
-	int		value;
-	int		index;
+	enum EWritability
+	{
+		WRITE_Mutable,		// normal read-many-write-many variable
+		WRITE_Const,		// write-once const variable
+		WRITE_Constexpr,	// const variable whose value is known to compiler
+	};
+
+	String			name;
+	String			statename;
+	EType			type;
+	int				index;
+	EWritability	writelevel;
+	int				value;
 
 	inline bool IsGlobal() const
 	{