Subsite with typeclass contexts and type variables

[jprider63]

I wasn't sure what category to add this to, but "Routing" seemed to make the most sense. Is there anything else you'd like me to add?

[psibi]

@jprider63 I will merge this once your code is merged there. Thanks!

[ajnsit]

This will be great for wai-routes as well. Since subsites currently use typeclass definitions, but this would help them go the other way round (i.e. use simple types).

[psibi]

@jprider63 Is there any motivation for having typeclass contexts and type variables ?

[jprider63]

My use case is I'm writing a subsite where the types are dependent on the parent site. I've written more about it in this post and this issue (yesodweb/yesod#1365).

[psibi]

Thanks!