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Showing content with the highest reputation on 09/04/2019 in all areas

  1. 1 point
    There are lots of design decisions with C++, C#, and Java that in hindsight are poor, but I don't feel like the author focused on the problematic parts, and maybe confused/conflated encapsulation and abstraction. In my opinion, this style of OO can be best described by: the ability to bundle data (something like a struct or record) and operations on that data (methods, which are essentially functions with an implicit "this" argument) into classes the ability to extend classes via inheritance, and automatically and irrevocably get subtype polymorphism, which can be ad-hoc through overrides the ability to hide implementation details within a class (private fields & methods) Additional ad-hoc polymorphism via interfaces I don't think I have a problem with a language having any of those features. I don't know if bundling data and operations is helpful, but I certainly don't think having the option is harmful. I do appreciate that the <class instance>.<method>() syntax is ergonomic. This can also be achieved by "." being syntax sugar where <expression>.<function>(...args) is equivalent to function(expression, ...args). I do think it's a problem when developers shoehorn their data types into convoluted inheritance hierarchies, but this isn't an OO problem. It's equally problematic when developers shoehorn data types into any convoluted data representation. I acknowledge that there may be some times where the type extension along with the subtype polymorphism may be an elegant representation. Hiding implementation details is not something I see as problematic at all, and it's not unique to OO languages. Other languages allow private struct fields and other definitions that are only usable inside the module where they're defined. It's nice when languages have something more powerful than these style of interfaces like Rust's traits or Haskell's typeclasses, but I don't think that makes interfaces bad, maybe just less useful. The big problems with these languages are: null - Anywhere you expect a class instance you must also expect the possibility of null. Terrible! unchecked exceptions - effectively an implicit potential return type of every function you write. Terrible! lack of type-safe sum-types/discriminated unions/tagged unions. Abstract parent class and multiple concrete children, the OO equivalent, is comparatively clunky. Scala's case classes are a nice implementation with an OOish flavor. lack of robust treatment of functions as data (this is improving as functional concepts are making their way into other languages) inability to extend the functionality of classes without subtyping Unsoundness in Java's type system via inappropriate generic covariance C++ being enormous and complicated loads of safety issues in C++, but it should get a partial pass for being a lower level language C++'s lack of package manager - this is an ecosystem problem, not a language problem verbosity What are the alternatives? Maybe<T> instead of null (a generic sum type which is either T or nothing. It must be cased on) Result<T, Error> instead of exceptions (another generic sum type that is either T or an error. It must be cased on, and what an "error" is a different language decision) Give the option for sum-types! Please LabVIEW! Give facilities for functions as data, lambda functions, partial application, etc. Rust-style traits, typeclasses Appropriate generic covariance/contravariance (invariance if you can't be sound otherwise - restrictive is better than unsound) Good package managers & build systems type inference What languages do these things well that are easy to use? In my opinion: TypeScript, F#, and Scala, which all also support OO stuff. Rust is probably my favorite language, but it is not easy. Haskell is great as a learning experience, but is definitely difficult and is so high level that it makes it hard to reason about when your program will do what at runtime because of laziness.
  2. 1 point
    Here is a new version 4.2.0b1 for the ZIP library. I didn't test it in every LabVIEW version on every platform. What I did test was MacOSx 32-bit and 64-bit LabVIEW 2014, Windows 32-bit and 64-bit LabVIEW 7.0, 7.1, 8.6, 2009, 2016, 2018, Linux 32-bit 7.1 and 8.6, and NI Linux x86 LabVIEW 2016. Other realtime targets I hadn't handy at the moment. Support for Linux 64-bit and NI Linux RT ARM as well as VxWorks and Pharlap is contained. The realtime support will only get extracted when installing into LabVIEW for Windows 32-bit and through a seperate exe file that is invoked and will prompt for an administrative elevation of this installer. You then have to go into NI Max and into the Software part of your target and select to install additional components. In the list should be an OpenG ZIP Tools version 4.2.0 package visible. Select that to be installed on your target. There are still following problems that I haven't implemented/fixed yet: 1) archives that contain file names with other encodings than your platform code page will go certainly wrong. This is probably not solvable without doing absolutely every file IO operation in the shared library too, since the LabVIEW file IO functions don't support any other encodings in the path. 2) If you try to zip up directories containing soft/hard inks then the current implementation will compress the actual target file/directory into the archive instead of a link and expanding zip archives that contain such links will expand just a small text file continaing the link destination. This is something I'm looking into to solve in the next release by allowing optionally adding a special link entry into the archive and create such a link on the filesystem when extracting. This is mostly of concern on Linux and MacOSX. While Windows also allows for such links nowadays it is still quite an esoteric feature and user accessible support for it is minimal (you have to use the command line or install additional third party tools to create/modify such links). Hope to hear from other platforms and versions and how it goes there. Without some feedback I'm not going to create a release. oglib_lvzip-4.2.0b1-1.ogp
  3. 1 point
    I would say here you are just describing what an Actor does and nothing specific to OOP. An Actor can be an object but doesn't have to be from my experience. I personally think that this use of inheritance can be the most difficult to actually understand/maintain as well. If you've ever used an NI's Actor Framework where the inheritance reaches depths of 5+, trying to understand what the Actor does can be quite difficult (though someone might claim this is because they violated SRP). Perhaps I'm missing some historical context though and should read some older papers.
  4. 1 point
    Breaking News: R&D expert at technology company predicts the end of the world within the next year!


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