Initial implementation of default parameters

Author: lofcz

src/MoonSharp.Interpreter/Tree/Expressions/IndexExpression.cs

@@ -10,7 +10,6 @@ class IndexExpression : Expression, IVariable
 		Expression m_BaseExp;
 		Expression m_IndexExp;
 		string m_Name;
-		private Token nameToken;
 		private bool inc;
 		private bool dec;
 		private bool nilCheck;
@@ -125,7 +124,7 @@ public void CompileAssignment(ByteCode bc, Operator op, int stackofs, int tuplei
 		{
 			if (isLength)
 			{ 
-				throw new SyntaxErrorException(nameToken, "Cannot assign to readonly property .length");
+				throw new SyntaxErrorException(null, "Cannot assign to readonly property .length");
 			}
 			if (op != Operator.NotAnOperator)
 			{

src/MoonSharp.Interpreter/Tree/Lexer/Lexer.cs

@@ -851,9 +851,7 @@ private Token ReadHashBang(int fromLine, int fromCol)
 		private Token ReadCMultilineComment(int fromLine, int fromCol)
 		{
 			StringBuilder text = new StringBuilder(32);
-
-			bool extraneousFound = false;
-
+			
 			for (char c = CursorChar(); ; c = CursorCharNext())
 			{
 				if (c == '\r') continue;
@@ -894,7 +892,6 @@ private Token ReadComment(int fromLine, int fromCol)
 				}
 				else if (c == '\n')
 				{
-					extraneousFound = true;
 					CursorCharNext();
 					return CreateToken(TokenType.Comment, fromLine, fromCol, text.ToString());
 				}

src/MoonSharp.Interpreter/Tree/Statements/FunctionDefinitionStatement.cs

@@ -11,14 +11,14 @@ class FunctionDefinitionStatement : Statement
 		internal class FunctionParamRef
 		{
 			public string Name { get; set; }
-			public Expression? DefaultValue { get; set; }
+			public Expression DefaultValue { get; set; }
 
 			public FunctionParamRef(string name)
 			{
 				Name = name;
 			}
 
-			public FunctionParamRef(string name, Expression? defaultValue)
+			public FunctionParamRef(string name, Expression defaultValue)
 			{
 				Name = name;
 				DefaultValue = defaultValue;