Re: Embedded blocks...

[Sergii Stoian]

On Oct 29, 2019, at 15:43, David Chisnall <address@hidden> wrote:

> On 29/10/2019 13:18, Ivan Vučica wrote:
>> Naive question: What’s the problem #ifdefing out the code that depends on 
>> blocks when building on gcc?
> 
> Locally?  Not much.  It means that anyone using clang and a GCC-built GNUstep 
> will have some surprises, but they probably will anyway because the GCC code 
> will support the (very) old ABI and not be useable with modern Objective-C 
> anyway.
> 
> Globally?  It means that we can't take advantage of things like ARC and 
> blocks usefully across GNUstep.  Both have significant developer productivity 
> wins, as does Objective-C++ (which mostly works with recent GCC, but still 
> has some quite rough edges).  If we have loads of developers with ample time 
> and aren't worried about the fact that it's hard to recruit new Objective-C 
> programmers when we force them to use a decade-old version of the language, 
> then that's not an issue either.
> 
> I haven't done much Objective-C recently, but the last time I did I found 
> that I could write about a quarter of the code in Objective-C++[1] with ARC 
> than I'd had to write in Objective-C with retain / release (and got smaller 
> and faster binaries).  After that experience, there's no way that I'd go back 
> to writing the kind of code that GNUstep requires.
> 
> David
> 
> [1] I have a small set of helpers that improve interop:
> 
> - C++ wrappers for -hash, -compare: and -isEqual: that let me use Objective-C 
> objects in C++ collections.
> 
> - A get<> template that calls a -{foo}Value method based on the type (e.g. 
> get<int>(id x) -> [x intValue]).  This allows me to write other C++ templates 
> that convert Objective-C objects to other types usefully.
> 
> - Wrappers for NSString and NSIndexSet that use the native range accessors to 
> implement C++ iterators, so these can be used with range-based for loops 
> (e.g. for (NSUInteger i : {some NSIndexSet}).
> 
> - An RIAA wrapper for posting KVO notifications.  Posts the will-change 
> notification on construction and the did-change notification on destruction, 
> so I never accidentally fail to send one of the pair.
> 
> I also make heavy use of a number of Objective-C features that GCC doesn't 
> support:
> 
> - Generics (type erasing, but they catch simple compile-time type errors).
> 
> - Array and dictionary literals.
> 
> - Blocks
> 
> - ARC
> 
> - Private ivar definitions in the @implementation context.
> 
> All of these either improve my productivity, increase the quality of the 
> code, or both.
> 

I absolutely agree with you, David. 
IMHO political motifs shouldn’t constrain technical decisions (besides licence, 
of course).
Moreover using these nice Objective-C 2.0 features make GNUstep code look much 
more familiar to potential macOS/iOS developers.

Sergii