[Zope-dev] Exceptions

[seb bacon]

I was just building in some error handling into some UI code, and wanted to catch errors relating to duplicate ids.  The problem is that just about every client-side error raises the same kind of Exception, a 'Bad Request'.  A quick grep counted 41 different types of 'Bad Request' in my Zope source.

Wouldn't it be *much* nicer to have a hierarchy of exception types, so that applications can deal with them at an arbitrarily granular level?  e.g.

ZopeException
    |
    `RequestException
      |  |
      |  `XMLException
      |
      `IdException
        |  |
        |  `ReservedWordException
        |
        `DuplicateException

Has this discussion taken place before?  Would it be useful?  Would its effort:benfits ratio be too great to justify doing?

seb