private object EvalExpression(Expression exp)
{
CurrentExpression = exp;
try {
if (exp is StringLiteral) {
return ((StringLiteral) exp).Content;
} else if (exp is Name) {
return GetValue(((Name) exp).Id);
} else if (exp is FieldAccess) {
FieldAccess fa = (FieldAccess) exp;
object obj = EvalExpression(fa.Exp);
string propertyName = fa.Field;
return ProcessProperty(obj, propertyName);
} else if (exp is MCall) {
MCall ma = (MCall) exp;
object obj = EvalExpression(ma.CallObject);
string methodName = ma.Name;
return ProcessMCall(obj, methodName, ProcessArguments(ma.Args));
} else if (exp is IntLiteral) {
return ((IntLiteral) exp).Value;
} else if (exp is DoubleLiteral) {
return ((DoubleLiteral) exp).Value;
} else if (exp is FCall) {
FCall fcall = (FCall) exp;
if (!_fnTbl.ContainsKey(fcall.Name)) {
string msg = string.Format("Function {0} is not defined", fcall.Name);
throw new TmplException(msg, exp.Line, exp.Col);
}
FunctionDefinition func = _fnTbl[fcall.Name];
object[] values = ProcessArguments(fcall.Args);
return func(values);
} else if (exp is StringExpression) {
StringExpression stringExp = (StringExpression) exp;
StringBuilder sb = new StringBuilder();
foreach (Expression ex in stringExp.Expressions) {
sb.Append(EvalExpression(ex));
}
return sb.ToString();
} else if (exp is BinaryExpression) {
return ProcessBinaryExpression(exp as BinaryExpression);
} else if (exp is ArrayAccess) {
return ProcessArrayAccess(exp as ArrayAccess);
} else {
throw new TmplException("Invalid expression type: " + exp.GetType().Name, exp.Line, exp.Col);
}
} catch (TmplException ex) {
DisplayError(ex);
return null;
} catch (Exception ex) {
string _Message = "Message=" + ex.Message + "," + "Source=" + ex.Source + ",StackTrace=" + ex.StackTrace + ",TargetSite=" + ex.TargetSite + "";
DisplayError(new TmplException(_Message, CurrentExpression.Line, CurrentExpression.Col));
return null;
}
}
private void visitExpression(Expression expression)
{
if (expression is Name)
WriteLine("Name: " + ((Name) expression).Id);
else if (expression is FCall) {
FCall fcall = (FCall) expression;
WriteLine("FCall: " + fcall.Name);
WriteLine("Parameters: ");
foreach (Expression exp in fcall.Args) {
visitExpression(exp);
}
} else if (expression is FieldAccess) {
FieldAccess fa = (FieldAccess) expression;
WriteLine("FieldAccess: " + fa.Exp + "." + fa.Field);
} else if (expression is StringLiteral) {
StringLiteral literal = (StringLiteral) expression;
if (literal.Content.Length > 50)
WriteLine("String: " + literal.Content.Substring(0, 50) + "...");
else
WriteLine("String: " + literal.Content);
} else if (expression is StringExpression) {
StringExpression sexp = (StringExpression) expression;
WriteLine("StringExpression");
foreach (Expression exp in sexp.Expressions) {
visitExpression(exp);
}
} else if (expression is BinaryExpression) {
BinaryExpression sexp = (BinaryExpression) expression;
WriteLine("BinaryExpression");
visitExpression(sexp.Lhs);
WriteLine("Operator " + sexp.Operator.ToString());
visitExpression(sexp.Rhs);
} else {
WriteLine("Expression: " + expression.GetType().ToString());
}
}