Commit 0d7f8ac

@@ -72,12 +72,12 @@ module Scim
             str('core:2.0:User') |
             str('core:2.0:Group') | (
               str('extension') >>
-              colon >>
-              alpha.repeat(1) >>
-              colon >>
-              version >>
-              colon >>
-              alpha.repeat(1)
+            colon >>
+            alpha.repeat(1) >>
+            colon >>
+            version >>
+            colon >>
+            alpha.repeat(1)
             )
           )
         end
@@ -171,6 +171,93 @@ module Scim
           end
         end
 
+        # @private
+        class Visitor
+          VISITORS = {
+            and: :visit_and,
+            co: :visit_contains,
+            eq: :visit_equals,
+            ew: :visit_ends_with,
+            ge: :visit_greater_than_equals,
+            gt: :visit_greater_than,
+            le: :visit_less_than_equals,
+            lt: :visit_less_than,
+            ne: :visit_not_equals,
+            or: :visit_or,
+            pr: :visit_presence,
+            sw: :visit_starts_with
+          }.freeze
+
+          def visit(node)
+            visitor_for(node).call(node)
+          end
+
+          protected
+
+          def visitor_for(node)
+            method(VISITORS.fetch(node.operator, :visit_unknown))
+          end
+
+          def visit_and(node)
+            visit(node.left).merge(visit(node.right))
+            raise error_for(:visit_and)
+          end
+
+          def visit_or(_node)
+            raise error_for(:visit_or)
+          end
+
+          def visit_equals(_node)
+            raise error_for(:visit_equals)
+          end
+
+          def visit_not_equals(_node)
+            raise error_for(:visit_not_equals)
+          end
+
+          def visit_contains(_node)
+            raise error_for(:visit_contains)
+          end
+
+          def visit_starts_with(_node)
+            raise error_for(:visit_starts_with)
+          end
+
+          def visit_ends_with(_node)
+            raise error_for(:visit_ends_with)
+          end
+
+          def visit_greater_than(_node)
+            raise error_for(:visit_greater_than)
+          end
+
+          def visit_greater_than_equals(_node)
+            raise error_for(:visit_greater_than_equals)
+          end
+
+          def visit_less_than(_node)
+            raise error_for(:visit_less_than)
+          end
+
+          def visit_less_than_equals(_node)
+            raise error_for(:visit_less_than_equals)
+          end
+
+          def visit_presence(_node)
+            raise error_for(:visit_presence)
+          end
+
+          def visit_unknown(_node)
+            raise error_for(:visit_unknown)
+          end
+
+          private
+
+          def error_for(method)
+            ::Scim::Kit::NotImplementedError.new("#{method} is not implemented")
+          end
+        end
+
         class << self
           def parse(filter)
             Node.new(new.parse(filter))

@@ -20,6 +20,7 @@ module Scim
   module Kit
     class Error < StandardError; end
     class UnknownAttributeError < Error; end
+    class NotImplementedError < Error; end
     TYPE_ERROR = ArgumentError.new(:type)
 
     def self.logger