private object Visit(SubtractNode node)
{
var left = Visit(node.Left);
var right = Visit(node.Right);
var function = GetFunction("op_Subtract", left.GetType(), right.GetType());
if (function == null)
{
throw new Exception("ugh");
}
var result = function.Invoke(new[] { left, right });
return(result);
}
private SyntaxNode OuterTerm(Parser.ParserInstance parser)
{
var node = InnerTerm(parser);
var ops = new[] { Program.Plus, Program.Minus };
while (ops.Contains(parser.Current.TypeId))
{
if (parser.Current.TypeId == Program.Plus)
{
parser.ConsumeToken();
node = new AddNode(node, InnerTerm(parser));
}
else if (parser.Current.TypeId == Program.Minus)
{
parser.ConsumeToken();
node = new SubtractNode(node, InnerTerm(parser));
}
}
// TODO: Comparisons
return(node);
}