Re: [PATCH v5] Enable xwidgets on macOS

[조성빈]

> 2019. 8. 1. 오전 11:35, Eli Zaretskii <address@hidden> 작성:
> 
>> Date: Wed, 31 Jul 2019 20:56:33 +0100
>> From: Alan Third <address@hidden>
>> Cc: Eli Zaretskii <address@hidden>, address@hidden
>> 
>> On Wed, Jul 31, 2019 at 12:33:36AM +0900, 조성빈 wrote:
>>>> 2019. 7. 30. 오전 5:26, Alan Third <address@hidden> 작성:
>>>> 
>>>> Anyway, the code contains two calls to
>>>> evaluateJavaScript:completionHandler: which is a problem as we’re
>>>> banned from using ObjC blocks, and the completion handler is an ObjC
>>>> block. Unless GCC supports them now, which I doubt.
>>> 
>>> Does that mean this patch can never get merged until gcc supports blocks?
>> 
>> We’ve had to remove blocks from Emacs code before because gcc doesn’t
>> support them, however Emacs can’t be built with gcc on recent (like,
>> the last decade or something) versions of macOS anyway. I don’t really
>> understand the logic, but it’s not my project.
>> 
>> I think it’s really up to Eli and/or RMS.
> 
> I don't think I understand the issue well enough to say anything
> intelligent.  What are "ObjC blocks",

"ObjC blocks" are anonymous functions that are used to pass arbitrary code 
between methods or to execute code as a callback within a method. It captures 
the surrounding state (it's a closure).

> and why this patch cannot do
> without them?

The WebKit API(evaluateJavaScript:completionHandler:) to execute arbitrary JS 
(and get the value) mandates the use of blocks.