The bad thing about it is, firstly you have to open the file to find out what it is, and that's very inefficient if you have to do a lot of them. Secondly, not all files are easy to identify that way.

Yeah, and on Unix anything, even with no file extension can be executable if that bit is set. So file extensions won't necessarily save you from anything malicious.

Yes all OSes need a mechanism where you can tell the file type. The argument is, file extension is not that right place for it.

Actually, a properly implemented scheme would NOT require the user to be intelligent. You might want to show the user, hey this is a Microsoft word file, but what's the point in making the user say deal with the whole .doc vs .docx distinction? Case in point, we check files out of share point as doc, we upgrade them to docx format, but guess what, it doesn't work because I can't change the file extension in SharePoint. All because of the stupidity of assuming that file name should be welded permanently to file type. Crazy stuff.

There is nothing wrong with file extensions to hold this information, or at least there wouldn't be if the computing universe was more geared up towards preserving it in various copy scenarios. In fact is say file extensions are definitely the RIGHT spot for it, it's just that the rest of the universe needs to catch up with it so they are preserved in all cases.

3 characters is an awful, error prone, non user friendly hint. Better the OS analyses the file on a more reliable criteria to tell you the file type in a different column.

That assumes a lot. It assumes the user has knowledge of the thousands of extensions in use and what they mean, and that he knows what app they are mapped to.

"Apple has not shipped a single API on Mac or iOS written in Swift. "

Apple has specifically designed Swift so that if the day comes that they are writing APIs in Swift instead of Objective-C, YOU WON'T EVEN KNOW. They have the same internal object model and memory layout. They are basically the same language with a different syntax. (Not quite, but it's not too far off).

And while Apple might not have declared Objective-C dead, people who've seen how Apple operate before can clearly see the writing on the wall.

To some extent it's true you can learn syntax in a few days. HOWEVER, learning to think in a paradigm is a different matter. How long to pick up Scheme syntax? An hour. How long to change your brain to think in Scheme, and not in C/Java/C++/C# ? Well that's a whole different matter.

The [[[][]]][] in Objective-C are an extremely simple concept to grasp. The same can't be said for all the >< in C++.

LOL, you just gave me deja-vu about my previous life as a C++ programmer.

Is Sather still alive and kicking? I thought it was dead. Come to that I thought Eiffel was dead.

Hmm, in my experience few people use C++ any more.

I might add that well designed programs don't generally open and close resources in lots of places in the code. They will abstract that out and have it done in only a few places.

Yes, as has been pointed out, Java since V7 now has try with resources to auto-close stuff. It's not like you can be totally oblivious in C++ either, you can easily lose resources too if you're pathologically stupid.