private object _execute(FunctionEnvironment functionEnvironment, VariableEnvironment variableEnvironment)
{
if (ParentExpression == null)
{
if (Identifier != null)
{
return(variableEnvironment.GetVariableValue(Identifier));
}
else if (Literal != null)
{
return(Literal.Execute());
}
else if (FunctionCall != null)
{
return(FunctionCall.Execute(functionEnvironment, variableEnvironment));
}
else
{
throw new Exception("Unknown expression");
}
}
else
{
object right;
if (Identifier != null)
{
right = variableEnvironment.GetVariableValue(Identifier);
}
else if (Literal != null)
{
right = Literal.Execute();
}
else if (FunctionCall != null)
{
right = FunctionCall.Execute(functionEnvironment, variableEnvironment);
}
else
{
throw new Exception("Unknown expression");
}
object left = ParentExpression._execute(functionEnvironment, variableEnvironment);
return(Operators.OperatorHelper.Execute(ParentExpression.Operator, left, right));
}
}
public object GetVariableValue(string identifier)
{
if (IsVariableDeclared(identifier))
{
return(DeclaredVariables[identifier].Value);
}
else if (ParentEnvironment != null)
{
return(ParentEnvironment.GetVariableValue(identifier));
}
throw new Exception("Undeclared identifer: " + identifier);
}