Gaby described how to obtain the type of a functor. A functor is an "unapplied" domain constructor. A domain constructor is an expression. So for example Complex Integer is a domain constructor. Complex is the functor.

Example Complex

(1) -> )boot getConstructorSignature 'Complex

   Your user access level is compiler and this command is therefore not
      available. See the )set userlevel command for more information.
--)boot getConstructorSignature('Complex).target

)boot first getConstructorSignature('Complex)

   Your user access level is compiler and this command is therefore not
      available. See the )set userlevel command for more information.
--)boot getConstructorSignature('Complex).source

)boot first rest getConstructorSignature('Complex)

   Your user access level is compiler and this command is therefore not
      available. See the )set userlevel command for more information.