public object Execute(ICodeNode node, ref int exec_count)
{
switch (node.Type)
{
case ICodeNodeType.VARIABLE:
{
// Get the variable's symbol table entry and return its value.
SymbolTableEntry entry = (SymbolTableEntry)node.GetAttribute(ICodeKey.ID);
return entry.GetAttribute(SymbolTableKey.DataValue);
}
case ICodeNodeType.INTEGER_CONSTANT:
{
// Return the integer value.
return node.GetAttribute(ICodeKey.VALUE);
}
case ICodeNodeType.REAL_CONSTANT:
{
// Return the integer value.
return node.GetAttribute(ICodeKey.VALUE);
}
case ICodeNodeType.STRING_CONSTANT:
{
// Return the integer value.
return node.GetAttribute(ICodeKey.VALUE);
}
case ICodeNodeType.NEGATE:
{
// Get the NEGATE node's expression node child.
List<ICodeNode> children = node.GetChildren();
ICodeNode expression = children[0];
// Execute the expression and return the negative of its value.
object value = Execute(expression, ref exec_count);
if (value is int)
{
return -(int)value;
} else if (value is double)
{
return -(double)value;
} else
{
return null;
}
}
case ICodeNodeType.NOT:
{
// Get the NOT node's expression node child.
List<ICodeNode> children = node.GetChildren();
ICodeNode expression = children[0];
// Execute the expression and return the "not" of its value
bool value = (bool)Execute(expression, ref exec_count);
return !value;
}
default:
// must be a binary operator
return ExecuteBinaryOperator(node, ref exec_count);
}
}
public static void Flag(ICodeNode node, RuntimeErrorCode error_code, MessageProducer backend)
{
//string line_number = null;
while (node != null && node.GetAttribute(ICodeKey.LINE) == null)
{
node = node.Parent;
}
// notify observers
var args = (Tuple<string, int>)Tuple.Create(error_code.Message, (int)node.GetAttribute(ICodeKey.LINE));
Message msg = new Message(MessageType.RuntimeError, args);
backend.Send(msg);
if (++Errors > MAX_ERRORS)
{
Console.WriteLine("*** ABORTED AFTER TOO MANY RUNTIME ERRORS.*");
Environment.Exit(-1);
}
}
private void SendMessage(ICodeNode node, string variable_name, object value)
{
object line_number = node.GetAttribute(ICodeKey.LINE);
// Send an ASSIGN message.
if (line_number != null)
{
var args = Tuple.Create((int)line_number, variable_name, (object)value);
Message msg = new Message(MessageType.Assign, args);
Send(msg);
}
}
private void SendSourceLineMessage(ICodeNode node)
{
object line_number = node.GetAttribute(ICodeKey.LINE);
// send the SourceLine message
if (line_number != null)
{
var args = (Tuple<int>)Tuple.Create((int)line_number);
Message msg = new Message(MessageType.SourceLine, args);
Send(msg);
}
}
