public Object Visit_UnaryExpr(UnaryExpr expr)
{
Object right = Evaluate(expr.right);
switch (expr.op.type)
{
case TokenType.Bang: return(!IsTruthy(right));
case TokenType.Minus: return(-(double)right);
}
throw new Exception("Unhandled case");
}
public object VisitUnaryExpr(UnaryExpr expr)
{
object right = Evaluate(expr.Right);
switch (expr.Oper.Type)
{
case TokenType.MINUS:
AssertNumberType(expr.Oper, right);
return(-(double)right);
case TokenType.BANG:
return(!IsTruthy(right));
}
// Should be unreachable.
throw new LoxRuntimeException(expr.Oper, $"UnaryExpr has unexpected operator: {expr.Oper.Type}.");
}
public object VisitUnaryExpr(UnaryExpr expr)
{
Resolve(expr.Right);
return(null);
}
public Void Visit_UnaryExpr(UnaryExpr expr)
{
Resolve(expr.right);
return(null);
}
public string Visit_UnaryExpr(UnaryExpr expr)
{
return(Parenthesize(expr.op.ToText(), expr.right));
}
