[plt-dev] Release Announcement for v4.2.5 -- 2nd call

On Fri, Apr 2, 2010 at 11:18 AM, Carl Eastlund <carl.eastlund at gmail.com> wrote:
> On Fri, Apr 2, 2010 at 8:34 AM, Eli Barzilay <eli at barzilay.org> wrote:
>> Carl:
>>  - contract stuff (r18009 and probably more)
>
>  The interface for projection-based contracts has been streamlined by the
>  introduction of blame objects and keyword-based constructors.  In addition,
>  custom contract structures now require only one structure property: either
>  prop:contract or prop:flat-contract, as appropriate.

Attempt #2:

 Writing new kinds of contracts is now easier with keyword-based
 constructors (make-contract and make-flat-contract), a simpler set of
 structure properties (prop:contract and prop:flat-contract), and the
 introduction of blame objects for tracking contract metadata.

--Carl