Re: No Bison 3 in untainted macOS installs

[Uxio Prego]

> On 21 Dec 2018, at 10:22, Hans Åberg <address@hidden> wrote:
> 
>> On 21 Dec 2018, at 10:00, Uxio Prego <address@hidden> wrote:
>> 
>>> A threaded parser aside, I found threading difficult to debug in general, 
>>> so good with a way to turn it off.
>> 
>> Not sure what do you mean. Threaded parser to me sounds like a *.y
>> source code doc where threads are spawned and joined in the inner
>> code blocks of grammar rules.
> 
> You snipped the part I replied to:
> 
>> - On performance or multithreading problems while in
>> Yacc mode:
>> 1. Proxy all parsing needs in a single thread and
>>   queue parsing requests.
> 
> I am not sure what you mean here. I looks like you want to make a threaded 
> parser, which I haven't tried.

My whole message was horrible, mixing Yacc parsing and
_contemporary_ Bison 2.3 parsing and contemporary Bison
3 parsing in not the clearest way.

Written in another way:

0. Consider a Yacc parser as a way to have a well
   documented common ground for Bison 2 and potential
   future releases of Bison departing from Bison 2 but not
   departing from Yacc compatibility - simply my own
   guess on the Bison roadmap, which I don't know, so I
   might be much wrong. I'm thinking that one can depart
   from Bison 2 much easier than from Yacc, as there are
   a lot more printed documentation (and non printed too)
   about Yacc than about Bison 2.

1. Once hit a multithreading problem (e.g. two threads are
   potentially wanting to parse some doc or string at a same
   time using the non reentrant but Yacc compatible Bison
   parser) proxy all parsing needs in a single thread, in
   order to avoid invalid access to the Yacc compatibility
   mode static globals.

2. After applying (1.) and once hit a performance issue (i.e.
   at some point or under certain circumstances one thread
   is not enough to handle all the parsing needs),
   convert the Yacc compatible parser in a Bison 2.3 pure
   parser, if `master` Bison is still compatible with Bison 2.
   Else convert the Yacc compatible parser in a `master`
   Bison pure parser, and then demand installs of the
   software on macOS to upgrade to contemporary Bison,
   ideally leaving the user the choice between a standalone
   Bison install, a Macports install, a Homebrew install,
   docker strategies, etc., unless in order to handle the rest
   of dependencies of the software using Bison, it strongly
   encourages one or several of these choices over the
   other choices.

Fortunately I can't think of any case where I could want to
spawn or join threads inside inner C blocks of grammar
rules. Anyway I suppose one can do this, specially if one
such thread is joined in the same inner C block which
spawned it.