protected void ProcessExpression(Expression exp)
{
object value = EvalExpression(exp);
WriteValue(value);
}
public void Add(Expression exp)
{
exps.Add(exp);
}
protected object EvalExpression(Expression exp)
{
_currentExpression = exp;
if (exp is StringLiteral)
return ((StringLiteral)exp).Content;
else if (exp is Name)
{
object obj = _variables[((Name)exp).Id];
return obj;
}
else if (exp is FieldAccess)
{
FieldAccess fa = (FieldAccess)exp;
object obj = _variables[fa.Exp];
string propertyName = fa.Field;
return EvalProperty(obj, propertyName);
}
else if (exp is IntLiteral)
return ((IntLiteral)exp).Value;
else if (exp is FCall)
{
FCall fcall = (FCall)exp;
if (!_functions.ContainsKey(fcall.Name))
{
string msg = string.Format("Function {0} is not defined", fcall.Name);
WriteError(msg, exp.Line, exp.Col);
return null;
}
TemplateFunction func = _functions[fcall.Name];
object[] values = new object[fcall.Args.Length];
for (int i = 0; i < values.Length; i++)
values[i] = EvalExpression(fcall.Args[i]);
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();
}
return null;
}
