From: Jim Weirich <jim@...>
Date: 2004-06-25T06:01:52+09:00
Subject: Re: rubygems thoughts


Sean O'Dell said:

> Use YAML as the control file instead of native Ruby.  I think it would
> make automating builds easier.  Ruby is okay when you're hand-crafting,
> but it makes automated build creation a little dicey.  Not terribly, but
> a little.

Actually, the .gemspec file is optional, and I never build one for my
projects.  I just use Rake to control the building of the
Gem::Specification object directly and then generate the gem from the spec
object.  Details can be found here:
http://rubygems.rubyforge.org/wiki/wiki.pl?CreateAGemUsingRake

If you want to build the spec automatically, but don't want to use Rake
(shame on you), just create the Gem::Specification object in your code (as
you would in a gemspec file).  To create the gem from the
Gem::Spcification, just use:

   builder = Gem::Builder.new(spec).build

If you want a yaml file out of the process, build the spec and write out
the results of spec.to_yaml.

> Also, it would make it easier for third-parties to display information
> about Gems.

The spec is actually encoded in the gem as a Yaml structure.  Extracting
that yaml structure is about 5 lines of code, but it would be nice if
there was library support for that (and there might be, I'm not sure). 
I'll look into that.

> I think Gems right now handles a little of the build process, but I have
> to tell you from experience, it doesn't handle everything, so my Gems
> build process is a hodge-podge of me partially creating the directory
> structure with some scripts, and then Gems seems to do some work of its
> own, adding directories according to the delete_if call.  Perhaps Gems
> shouldn't do any building at all; perhaps it should be more like Debian
> apt where all it does is bundle what you tell it to using a control file
> with meta information.
>
> Leaving the build process to the developers seems natural to me, and it
> would make your (Gems developers) job easier and more clear.  All you
> would have to do it install what the control file tells you to.  Let the
> developers create their directories in the way they want, and generate the
> control  file, Gems could just bundle it all up and handle the
> distribution tasks (download, install, uninstall, etc.).
>
> I hope that made sense.  It seems like a lot to ask for, but it should
> eliminate a whole lot of code surrounding the gem build process.  If what
> I'm thinking came out right, it should amount to more control to the
> developers, less work for you guys and good meta information for everyone.

I will confess that I've read the above several times and am a bit
confused.  Are you refering to the process of bundling up the package
files in to a gemfile, or  the process where a gem file is installed onto
a system.

I think it is the former, but then I'm not sure what part of the build
process you think gem performs.  I am not aware of any directories added
by the "gem -b" command.  Could you give an example?

And again, thanks for the feedback.

-- 
-- Jim Weirich     jim@weirichhouse.org    http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)