Very close to some sort of "Type Classes" for structures if <div>a) Ability to define and label a set of typed generic methods.<div>b) Declare a structure as satisfying a given set of typed generic methods.</div> <div>c) TR verify said satisfaction.</div><div><br></div><div>I've successfully attached a TR typed writer method to a struct:'s #methods gen:custom-write for example.<br><br><div class="gmail_quote">On Tue, Aug 14, 2012 at 10:17 AM, Asumu Takikawa <span dir="ltr"><<a href="mailto:asumu@ccs.neu.edu" target="_blank">asumu@ccs.neu.edu</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On 2012-08-13 13:28:07 -0700, Jordan Johnson wrote:<br> > I'm curious: what use cases call for the new generics as opposed to<br> > the old class & interface system? I'm trying to get a clearer picture<br> > of the motivation for the new functionality, and the differences<br> > between old-style class-based OO code and this struct-based kind.<br> <br> </div>This feature isn't intended to replace class-based OO code. Notably,<br> these generics don't have inheritance, overriding, mixins, and other<br> "heavyweight" features that you might use with the class system.<br> <br> Instead, racket/generic is intended to replace the use of struct type<br> properties as a mechanism to add generic behavior to datatypes. Before<br> this library, generic functions like `dict-ref` or `stream-first` relied<br> on ad-hoc protocols where a struct would provide a collection of<br> functions to implement dictionary operations.<br> <br> Now we provide a unified and consistent way to define such generic<br> functions and implement their behavior on specific instances.<br> <br> Cheers,<br> Asumu<br> <div class="HOEnZb"><div class="h5">____________________<br> Racket Users list:<br> <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a><br> </div></div></blockquote></div><br></div></div>