On Oct 29, 2019, at 15:43, David Chisnall <gnus...@theravensnest.org> 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
