[MIT-Scheme-devel] customizing dispatch tags and dispatching on URIs

[Taylor R Campbell]

I have not read the code implementing generic procedures and dispatch
at any level beyond idle skimming, and skimming was enough to deter me
from trying to read it more closely until I should find a spare
afternoon to spend on it, so I figured I'd pose my question here
instead of waiting for that spare afternoon...

After thinking a bit about the structure of IMAIL, and considering
integrating its idea of URLs with the run-time system's more recent
idea of URIs, I'm curious: would it be possible to specialize generic
procedure methods on different types of URIs, depending on the value
of the scheme field, the final component of the path (specifically,
whether it is empty or not, signifying a container versus a folder),
and so on?

This is very convenient in the implementation of IMAIL, but IMAIL
relies on having multiple different classes for URLs and some complex
infrastructure for parsing and unparsing them, which seems like a bit
of a kludge to map the concept of URLs onto the kind of class
hierarchy provided by CLOS/SOS.

I'm also curious: was the idea of resources, their locators, and their
containers originally part of a somewhat grander scheme for more
general application that ended up remaining isolated inside IMAIL, or
was IMAIL just designed with internal names that give this appearance?