Often, when you call clojure.core/extend directly (vs extend-type, extend-proto or inline definitions), that means you have some level of composition that happened upstream to create proto extensions for a type.
To recap today the signature of extend is as follows:
([atype & proto+mmaps])
Meaning when it's called it looks like
(extend t protoA {...} protoB {...})
I am advocating to just changing it to
([atype & {:as proto+mmaps}])
That would allow somebody calling into extend to pass either an "unrolled" map like today, or a regular map to it (leveraging the recent patch from @fogus).
(extend t {protoA {...} protoB {...}}) and (extend t protoA {...} protoB {...}) would be supported.
The alternative today when you have a proto+mmaps that is the result of merging implementations is to do something akin to:
(apply extend t (into [] cat proto+mmaps))
the patch would allow to do things such as:
(extend t (merge proto-impl-a proto-impl-b proto-impl-c ...))
I am happy to provide a patch for this if that's considered to be an acceptable change.
