<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I recently ran into a problem in which opaque types (types imported from untyped code) cannot by parameterized by Typed Racket. I initially encountered this problem in <a href="https://github.com/lexi-lambda/racket-2htdp-typed/issues/1" class="">my attempt to port 2htdp/image to TR</a>.<div class=""><br class=""></div><div class="">After some further consideration, I’m interested in adding support to make something like this possible, which would certainly have additional benefits beyond this specific use-case. I’ve outlined my proposal here:</div><div class=""><a href="http://lexi-lambda.github.io/racket-parametric-opaque-types/" class="">http://lexi-lambda.github.io/racket-parametric-opaque-types/</a></div><div class=""><br class=""></div><div class="">Any feedback, suggestions, or advice would be appreciated, especially from those who are familiar with Typed Racket’s internals.</div><div class=""><br class=""></div><div class="">Thank you,</div><div class="">Alexis</div></body></html>