Re: [Boost-build] Upgrading the lexer

Subject: Re: [Boost-build] Upgrading the lexer
From: Rene Rivera (grafikrobot_at_[hidden])
Date: 2018-02-11 05:41:31

On Fri, Feb 9, 2018 at 10:05 AM, Steven Watanabe via Boost-build <
boost-build_at_[hidden]> wrote:

> AMDG
>
> On 02/09/2018 06:25 AM, Rene Rivera via Boost-build wrote:
> > On Fri, Feb 9, 2018 at 7:07 AM, Fabien Chêne via Boost-build <
> > boost-build_at_[hidden]> wrote:
> >
> >>
> >> I was wondering if it were possible to extend the bjam grammar so that:
> >>
> >> rule lib ( name : sources * : requirements * )
> >>
> >> can be called either (possibly using named arguments coming from the
> >> rule definition):
> >> lib foo : a.C b.C : requirements <define>XXX ;
> >> lib foo : sources a.C b.C : requirements <define>XXX ;
> >> lib foo : requirements <define>XXX : sources a.C b.C ;
> >> lib sources a.C b.C : name foo : requirements <define>XXX ;
> >>
> >> What do you think ?
> >>
> >
>
>   I already implemented this in develop.  It is implemented
> as a library extension rather than a language extension,
> so rules must explicitly make use of it:
>
> param.handle-named-params sources requirements
>   default-build usage-requirements ;
>
> I applied it to all main-target rules.
>
> > IIRC we discussed this some long time ago.. You example usage is not
> "easy"
> > to accomplish in a backward compatible way.
>
>   It's true that it isn't perfectly backwards compatible,
> but I didn't find any conflicts in Boost.  Also, applying
> it on a per-rule basis is much safer than baking it into
> the language.
>

That's a reasonable solution too.

> The best alternative that I
> > remember was having the argument names be a special format. For example:
> >
> > lib foo : a.C b.C :requirements <define>XXX ;
> > lib foo :sources a.C b.C :requirements <define>XXX ;
> > lib foo :requirements <define>XXX :sources a.C b.C ;
> > lib :sources a.C b.C :name foo :requirements <define>XXX ;
> >
> > That is having named arguments be ":<arg-name> arg .." (colon prefixed).
> > Which would allow to distinguish them and the list value from all the
> other
> > arguments. How does that sound to you?
> >
>
> That syntax conflicts with changing the lexer.
>

Good point.. Although it would be nice to have some syntax that would apply
at the language level. As it would be useful in general coding itself.

-- 
-- Rene Rivera
-- Grafik - Don't Assume Anything
-- Robot Dreams - http://robot-dreams.net