Macro-generated deftype with type-hinted fields.

hinttype.clj

(defmacro hinttype
  [type-name & hint-symbols]
  `(deftype ~type-name
     [~@(for [s hint-symbols] 
          (with-meta (gensym "a") 
            {:tag (case s 
                    :int 'int
                    :long 'long
                    :float 'float
                    :double 'double
                    :char 'char
                    :short 'short
                    :boolean 'boolean
                    :byte 'byte
                    'Object)}))]))

(hinttype alpha :int :long :double)
(alpha. 1 2 3) ;success
(alpha. "hi" 2 3) ;failure