From: Hugh Sasse Staff Elec Eng <hgs@...>
Date: 2000-08-10T10:53:19+01:00
Subject: [ruby-talk:04396] Re: New Require (was: RAA development ideas (was: RE:  Looking for inp ut on a 'links' page))

On 9 Aug 2000, Dave Thomas wrote:

> OK - maybe now's the time to mention an idea I've been mulling over.
	[...new require operation...] 
> So... we can then find out all the meta-data about a module as we load 
> it in. We could do things like:
> 
>    module Kernel
>      def requireVersion(name, version)
	[...including call res.versionCompatible(vesion)...]
>      end
>    end
> 
> 
> So in normal user code, you'd write:
> 
>    requireVersion 'wombat', '1.3.4'
> 
> Which would either work transparently or output a message such as
> 
>     Package wombat, requested 1.3.4, got 1.2.3
>     Latest version available from ftp://ftp.pragprog.com/pub/....
> 

This seems useful to me.  The only thing I see missing from this is

We want version 1.3.4 or newer, but we know that we don't want 1.3.8,
because that only lasted 6 hours until the bug (that slipped throgh the
regression tests) breaking earlier working code was found.  But we don't
want to force users of 1.3.{4,5,6,7} to upgrade.

So this may depend on where versionCompatible() is implemented (If the
requiring module redefines it then there is more flexibility, but it is
harder to use).

> 
> 
> Matz:
> 
> If you think this has merit, and we can all refine the details here on 
> the list, I'd be happy to do the actual work in 1.7.
> 
> 
> 
> Dave
> 
	Hugh
	hgs@dmu.ac.uk