 # force formula evaluator
 
-class Evaluator
-  constructor: (@data) ->
-  visitLiteral: (node) ->
-    node.value
-
+class FormulaVisitor
+  constructor: ->
   visitIntegerLiteral: (node) ->
     @visitLiteral node
   visitDecimalLiteral: (node) ->

    @visitLiteral node
  visitParens: (node) ->
    node.formula.visit @
  visitReference: (node) ->
    @data[node.name]
  visitComparison: (node) ->

      when '>='
        left >= right

class Unbound extends FormulaVisitor
  constructor: ->
  visitLiteral: ->
    []

  visitReference: (node) ->
    [node.name]
  visitComparison: (node) ->
