[racket-dev] 5.0.2 changelog

On Oct 26, 2010, at 2:34 PM, Jon Rafkind wrote:
> Here is the raw changelog for 5.0.2. If you would like to summarize your
> changes please do so, otherwise someone (me/eli/ryan) will do it for
> you. If there are any other important items to note for this release
> please make a note of them.
> Stevie Strickland
> commit ec0711bf4996dde06ecddbc8fcb95f44987a6915
>    Add chaperone contract-related properties.
> 
>      * Flat contracts are chaperone contracts, and chaperone contracts
>        are (proxy) contracts.
>      * Check in chaperone contracts that a chaperone (or chaperone-friendly
>        value) is indeed returned.

This isn't really the important commit to emphasize from an external viewpoint.  Here's what I'd probably summarize for the release notes.

-----

The `box/c', `hash/c', `vector/c', and `vectorof' contract combinators now accept higher-order contracts.  In addition, operations on contracted mutable boxes, hash tables, and vectors are appropriately checked.  While the new behavior means that these contracts are now sound, the additional checking may impact performance.  The old behavior of these contracts is still available if desired: see the documentation for more details.

-----

Stevie