On Apr 30, 2007, at 11:42 AM, Brian Guthrie wrote: > It's the sort of library that shouldn't necessarily be used in > production code anyway, though, due to the performance hit you take > from having to run each and every single method call through a filter. Makes sense. Reminds me of Eiffel's ability to monitor pre/post conditions during development but to turn off those checks in production. One of the things that I thought was really nice about Eiffel's pre-condition checks was that any pre-condition exceptions were raised in the caller's context, which is conceptually where the error exists. I think that would be difficult to do in Ruby without support in the runtime. Gary Wright