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mpweiher

Objective-C is a dynamic OO language and it has always been AOT compiled.

Also there's Smalltalk/X: http://www.exept.de/en/products/smalltalkx

libart for Android also brings AOT to a jitted/VMed language.

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> Objective-C is a dynamic OO language

Objective C is not a dynamic language.

Do not confuse dynamic language with dynamic typing or whatever the standard wisdom in the Apple cult is.

I'd certainly say that it is, it certainly meets the dynamic binding pre requisite. And small talk certainly does, so why does Objective-C not qualify?

Because of the C subset.

Many languages have static subsets. For example, many languages won't let you change the meaning of `1+1` while others might allow you to dispatch the addition dynamically.

In fact, a static subset is a very nice property to have in a dynamic language. It's probably the easiest way to make a dynamic language self-hosting. For instance, PyPy uses a static subset of Python called RPython and Squeak uses a subset of Smalltalk called Slang.

Sure is.

Supported:

Dynamic typing.

Fully dynamic message dispatch with doesNotUnderstand: (called forwardInvocation:), proxies, Higher Order Messaging, etc.

Addition of (a) classes ( objc_registerClassPair() ) and (b) methods ( class_addMethod() ) at runtime.

Changing an object's class at runtime (objc_setClass() slightly hacky, but done by system services such as KVO, so supported).

Closures/Blocks.

Reflection.

Addition of (associated) instance variables at runtime. Interpreted languages can be fully interoperable peers.

Not supported:

Eval (but see above re: interpreted peers).

Continuations.

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See: https://developer.apple.com/library/mac/documentation/Cocoa/...

EDIT: added references.

> Addition of (a) classes (b) methods at runtime.

This is news to me.

Always glad to help you learn new stuff :-)

How do you dynamically?

- add fields to a struct

- create a function

Objective-C is only dynamic typed in the OO runtime, everything else is static typed.

Dynamic languages are 100% dynamic, unless the CS classification got changed in the last years.

That's just silly.

By that definition, Smalltalk is not a dynamic language: you cannot change the definition of assignment ( := ), message return ( ^ ) or the messenger itself. You also cannot change the the way the GC works.

> That's just silly.

No it is not. I can do that in fully dynamic languages like TCL and Python, for example.

You forgot Lisp, Scheme, Dylan, Julia, Basic.

Funny enough, even C#: http://www.mono-project.com/AOT

This is used to run C# on iOS.

Still does.

C# is not a dynamic language.

Not by default no, but it easily supports dynamic code through 'dynamic'

The use of dynamic keyword and interface, doesn't make it dynamic from CS semantic analysis point of view.

C# allows generating and re-writing code at runtime. Couple that with reflection, bypassing private/protected modifiers etc. Does that make it dynamic? Genuinly interested, what defines a dynamic language?

Julia isn't AOT compiled. Indeed, one of the things that makes it so fast is that it does JIT compilation of method bodies using runtime information to drive type inference and to produce multiple type-specialized copies of methods.

Silly me, you are right. I forgot about it.

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