 #       ....
 #    }
 # 
-class HoistVars extends NodeVisitor
+class HoistVars extends TreeTransformer
         constructor: () ->
                 super
                 @function_stack = new Stack

#     parent: ...  // the parent environment object
#   }
# 
LocateEnv = class LocateEnv extends NodeVisitor
        constructor: ->
                super
                @envs = new Stack


# this should move to echo-desugar.coffee

class HoistFuncDecls extends TreeTransformer
        constructor: ->
                @prepends = []
                
