'Inheritence' of map based hierarchy

[Colin Yates]

I have an abstract type of 'command' and a number of sub types, only they are all expressed as maps not defrecords. 

At the moment I have:

(t/defalias CommandSchema (t/HMap :mandatory {:type Keyword}))

and

(t/defalias SayHelloSchema (t/HMap :mandatory {:type :say-hello :to-whom String}))

is there any way I can express and enforce that SayHelloSchema is-a (even if only structurally) with CommandSchema?

The *only* reason I ask is to capture that relationship - things that need a CommandSchema take a CommandSchema, things that expect a SayHelloSchema take one of those, it would just be nice to capture that relationship.

Thanks

[Ambrose Bonnaire-Sergeant]

Something like (fn [m :- SayHellowSchema] :- CommandSchema, m) would work :)

[Colin Yates]

Isn't that stating the function consumes a SayHelloSchema and returns a CommandSchema or am I confused?

[Ambrose Bonnaire-Sergeant]

That just says a value that is of type SayHelloSchema is also a CommandSchema.