[r6rs-discuss] library versions

From: Shiro Kawai <shiro>
Date: Thu, 28 Jun 2007 14:36:12 -1000 (HST)

From: Matthew Flatt <mflatt at cs.utah.edu>
Subject: Re: [r6rs-discuss] library versions (was: Rationale issues)
Date: Fri, 29 Jun 2007 05:30:32 +0800

> But when it comes to distributing a library to users who don't have
> access to your SVN repository, or who are combining libraries from many
> different sources (managed in different repositories), then it makes
> sense to put a version number at packaging time, at least on modules
> that are intended for external use.
>
> I expect the main use of the version number to be: package A depends on
> package B, and the implementor of A knows (for whatever reason) that it
> works only with a sufficiently new version of B. To save users the
> hassle of guessing which version is needed, A explicitly requires
> "version X or greater" of B.

That's perfectly reasonable argument, but I don't think that
supports current versioning spec at all.

See <20070617.020358.113788959.shiro at lava.net> for the problems
of the current spec. In short,

* Lack of facility to switch code (in library A) depending on the
  version of B severely clipples versioning features.
* Versions and dependencies are a problem larger than Scheme world
  itself, and can't be solved solely in the R6RS world.

One may argue that having something is better than nothing.
But it doesn't justify putting unnecessarily complications
into the standard. I submitted a formal comment to simplify
the current spec without losing usability in the practical
situations like you described above.

The editors are trying hard to put the final draft in the
planned limit and seems to be afraid of change. If we don't
have enough time to put enough consideration to the feature,
I'm for dropping the feature, though.

--shiro
Received on Thu Jun 28 2007 - 20:36:12 UTC