From: Dave Thomas <Dave@...>
Date: 2001-02-26T14:08:10+09:00
Subject: [ruby-talk:11567] A design/implementation question


I'm looking for some inspiration.

'ri' displays information about Ruby methods etc. It holds these
descriptions in a set of marshaled objects, one per class or
module. These marshaled objects ae prepared as I ship ri, using a
simplified form of the XML used to generate the online book.

Now, my problem is that marshaled classes are dependent on the Ruby
version number: I'm writing the classes out using 1.6.2, and someone
who's trying to use ri with 1.6.1 will get an error.

So, ideally I'd like to construct these marshaled classes not when I
generate the distribution at my end, but instead when I install it on
a target machine.

To do that with the current scheme would require that every client
have the Ruby xmlparser module installed, which in turn requires Jim
Clark's expat library. This seems onerous!

So, I initially started hacking together yet another flat file
representation of the data. I'd ship it with ri, and when you type
'ruby install.rb', the installer would read it and generate the
marshaled classes. Then that little alarm bell started ringing that
said "there has to be a better way". Unfortunately, the battery ran
down before it got around to telling me what that better way is.

So, any ideas?


Thanks


Dave