maybe this is just a little misunderstanding but how can a programming language be implemented?
I’m not talking about how to implement my own programming language but about the word “implemented”?
I mean, you can implement a compiler or an interpreter, but a programming language?
What does it mean if I read “C++ is implemented in C” or “Python was implemented in C”?
I think a language is more sth. like a protocol of how someone thinks about things should be implemented. For example, if he wants do display a messagebox he can say the command for this is ShowMessageBox(string) and implement a compiler who will translate this into something that works on a computer (aside from the selected programming paradigms he imagines).
I think this question leads to the question “what is a programming language in reality”? A compiler, an interpreter or just a documented language standard about how things should be implemented in a language?
[EDIT]
Answer: Languages are never implemented, only compilers/interpreters etc. It’s this simple.
You are right, those statements don’t make any sense. It’s pretty obvious that whoever made those statements doesn’t understand the difference between a programming language and a compiler (or interpreter).
This is a surprisingly common problem. For example, sometimes people talk about interpreted languages or compiled languages. That’s the same thing: languages aren’t interpreted or compiled, they just are. Interpretation and compilation are traits of the implementation not the language.
Another goodie: Python has a GIL. No, it doesn’t: one implementation of Python has a GIL, all the other implementations don’t, and the Python Language itself certainly doesn’t. Or: Ruby has green threads. Again, not true: Ruby has threads. Period. Whether any particular language implementation chooses to implement them as green threads, native threads, platform threads or whatever, is a trait of that particular implementation, not of Ruby. And of course my favorite: Ruby 1.9 is faster than Ruby 1.8. This doesn’t even make sense: Ruby 1.9 and Ruby 1.8 are programming languages, i.e. a bunch of abstract mathematical rules. You cannot run a programming language, therefore a programming language can never be “faster” or “slower” than another one.
The most blatant confusion about the difference between programming languages and implementations is the Computer Language Benchmark Game, which claims to benchmark languages against each other but in fact benchmarks implementations.
All of these are just different expressions of the fact that apparently some people seem to be fundamentally incapable of grasping the concept of abstraction. Or at least the concept of having an abstract language and a concrete implementation of that language.
If we go back to the statement that “Python is implemented in C”, it should now be obvious that that statement is not just wrong. If the statement were wrong that would imply that the statement even makes sense, i.e. that there is some possible world out there, in which it could at least theoretically be right. But that’s not the case. The statement is neither wrong nor right, it simply doesn’t make sense. If English were a typed language, it would be a type error.
Python is a programming language. Programming languages aren’t implemented in anything. They are just implemented. Compilers and interpreters are implemented in languages. But even if you interpret the statement this way, it isn’t true: Jython is implemented in Java, IronPython is implemented in C#, PyPy is implemented in RPython and Python, Pynie is implemented in PGE, NQP and PIR. (Oh, and all of those implementations have compilers, so there goes your “Python is an interpreted language”.) Similar with Ruby: Rubinius is implemented in Ruby and C++, JRuby and XRuby are implemented in Java, IronRuby and Ruby.NET are implemented in C#, HotRuby is implemented in ECMAScript, Red Sun is implemented in ActionScript, RubyGoLightly is implemented in Go, Cardinal is implemented in PGE, NQP and PIR, SmallRuby is implemented in Smalltalk/X, MagLev is implemented in GemStone Smalltalk and Ruby, YARI is implemented in Io. And for C++: Clang (which is the C, C++ and Objective-C front-end for LLVM) is implemented in C++ (all three front-ends are implemented in C++).