private bool TryParseFactor(out AstNode node)
{
if (IsNext(TokenType.Minus))
{
var op = Accept();
if (TryParseImplicitMultiplication(out node))
{
node = new NegationUnaryOperatorAstNode(op, node);
}
else
{
throw new Exception($"Exception parsing the factor rule at position {_lexer.Position}");
}
}
else
{
TryParseImplicitMultiplication(out node);
}
return(node != null);
}
private double Evaluate(NegationUnaryOperatorAstNode node) => - 1 * Evaluate(node.Target as dynamic);
