I haven't seen this specifically, but I have seen other languages move common top level behaviors within functions into parameter lists.

Ruby, dart, coffescript allow setting of instance variables from the parameter list:

    class Example
      constructor: (@name) ->
        # do stuff

    class Example
      constructor: (name) ->
        @name = name
        # do stuff

Jonathan Blow's language allows the `using` keyword in parameter list, which desugars in much the same way.

I'm personally not a big fan of using this technique for pattern matching, but its better than requiring explicit match blocks everywhere (like Scala and rust).