Stephen Pair spair at
Thu May 20 02:01:38 UTC 1999

Very thing the could advance Squeak in very positive ways is to
add a mechanism for capturing developer knowledge at development time.  That
implies capturing type information for parameters and return values.  Java
does that in such an awful way (via a hacked static typing scheme).  What I
would like is a way to capture and leverage this semantic knowledge that the
developer has, without burdening the implementation.

I can imagine an environment that, during testing, type validations could be
performed as messages are passed among objects.  During runtime, such
validations could disabled (just as you have done).  If you encounter an
unhandled exception, opening the debugger would show, in red, the contexts
where interface contraints were violated.  The problem could be rectified at
the highest level context, where the constraints were first violated...thus,
potentially fixing one problem, and not a dozen symtoms.

This is a great step in that direction.

- Stephen

> -----Original Message-----
> From: Benoit St-Jean [mailto:lamneth at]
> Sent: Wednesday, May 19, 1999 7:52 PM
> To: squeak at
> Subject: Assertions
> For those of you who don't have the time to integrate signatures in the
> Squeak environment or for those who want a fast and simple way to
> have some
> kind of assertion mechanism within Squeak, here's a quick and dirty
> Assertion mechanism.
> 2 attached files

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