A version of clojure.core/extend-protocol with (possibly) more conciseness.

Extends protocols to multiple types which share identical implementations. A series of names appearing before an implementation of the protocol expands into repeated implementations for each individual type.

Recommended: Supply class/type names as symbols or nil; expressions intended to be evaluated will convey the inconsistent behavior of the underlying clojure.core/extend-protocol.

Note: No additional checking is performed to ensure that the protocol’s implementation is valid.

Example:

(multi-extend-protocol AProtocol
  AType
  BType
  AClass
  (foo [x] x)
  (bar [y] y)
  (baz [z] z)

  DType
  EClass
  (foo [x] (inc x))
  (bar [y] (dec y))
  (baz [z] (identity z))

  FType
  nil
  (foo [_] 99)
  (bar [_] 42)
  (baz [_] 0))

…expands to…

(clojure.core/extend-protocol AProtocol
  AType
  (foo [x] x)
  (bar [y] y)
  (baz [z] z)

  BType
  (foo [x] x)
  (bar [y] y)
  (baz [z] z)

  AClass
  (foo [x] x)
  (bar [y] y)
  (baz [z] z)

  DType
  (foo [x] (inc x))
  (bar [y] (dec y))
  (baz [z] (identity z))

  EClass
  (foo [x] (inc x))
  (bar [y] (dec y))
  (baz [z] (identity z))

  FType
  (foo [_] 99)
  (bar [_] 42)
  (baz [_] 0)

  nil
  (foo [_] 99)
  (bar [_] 42)
  (baz [_] 0))