[Zope3-dev] Re: Merging schema & interfaces (was: "Sub interface")

[Gary Poster]

Casey Duncan wrote:
> On Tue, 02 Mar 2004 10:29:56 -0500
> Gary Poster <gary at modernsongs.com> wrote:
>>We have a first stab on how to do this.  One of our interfaces has
>>
>>     invariant(isGreater(
>>         "expiration_date", "publication_date",
>>         _("${field1} must be later than ${field2}")))
> 
> 
> I seems to me like this would generate an excessive amount of trivial
> code. 

If you care about message ids, helpers like this very much come in 
handy.  If you don't, the examples you and Jim gave work fine. :-)

Gary