Question

I have the following in one namespace say shapes:

(derive ::rect ::shape)
(derive ::square ::rect)

Now executing the following in the shapes namespace:

(isa? ::square ::shape)

returns true. But when I execute the following in a namespace where I actually implement multimethods for drawing,

(isa? ::square ::shape)

it returns false. So even though I have the correct multimethod dispatch functions in place I get an error that says “no dispatch function found”.

Am I missing something? Implementing all types of shapes in one giant namespace seems pointless to me.

Answer 1

Turns out, :: uses the current namespace so in order to use types from other namespaces you need to use fully qualified names such as :shapes/square.