private static void ParseConst(Scope scope, LuaLexer code)
{
// const ::= variable '=' ( expr | clr '.' Type )
Token tVarName;
Type typeVar;
ParseIdentifierAndType(scope, code, out tVarName, out typeVar);
if (code.Current.Typ == LuaToken.Identifier || code.Current.Value == "typeof")
{
code.Next();
// Parse the type
scope.RegisterConst(tVarName.Value, Expression.Constant(ParseType(scope, code, false)));
}
else
{
FetchToken(LuaToken.Assign, code);
Expression exprConst = ParseExpression(scope, code, InvokeResult.Object, false); // No Debug-Emits
if (typeVar != typeof(object))
exprConst = ConvertExpression(scope.Runtime, tVarName, exprConst, typeVar);
// Try to eval the statement
if (exprConst.Type == typeof(object) || exprConst.Type == typeof(LuaResult)) // dynamic calls, no constant possible
throw ParseError(tVarName, Properties.Resources.rsConstExpressionNeeded);
else
try
{
object r = EvaluateExpression(exprConst);
if (r == null) // Eval via compile
{
Type typeFunc = Expression.GetFuncType(exprConst.Type);
LambdaExpression exprEval = Expression.Lambda(typeFunc, exprConst);
Delegate dlg = exprEval.Compile();
r = dlg.DynamicInvoke();
}
scope.RegisterConst(tVarName.Value, Expression.Constant(r, exprConst.Type));
}
catch (Exception e)
{
throw ParseError(tVarName, String.Format(Properties.Resources.rsConstExpressionEvalError, e.Message));
}
}
}
