implement distinct_of validator

lib/goo/validators/enforce.rb

@@ -41,6 +41,8 @@ def enforce(inst,attr,value)
               check Goo::Validators::DataType, inst, attr, value, opt, Float
             when :symmetric
               check Goo::Validators::Symmetric, inst, attr, value, opt
+            when /^distinct_of_/
+              check Goo::Validators::DistinctOf, inst, attr, value, opt, opt
             when Proc
               call_proc(opt, inst, attr)
             when /^max_/, /^min_/

lib/goo/validators/implementations/distinct_of.rb

@@ -0,0 +1,36 @@
+module Goo
+  module Validators
+    class DistinctOf < ValidatorBase
+      include Validator
+
+      key :distinct_of_
+
+      error_message ->(obj) { "`#{@attr}` must be distinct of `#{@property}`"}
+
+      validity_check -> (obj) do
+        return true if self.class.empty_value?(@value)
+
+        self.distinct?(@inst, @property, @value)
+      end
+
+      def initialize(inst, attr, value, key)
+        super(inst, attr, value)
+        @property = property(key)
+      end
+
+      def property(opt)
+        opt[self.class.ids.size..opt.length].to_sym
+      end
+
+      def distinct?(inst, property, value)
+        target_values = self.class.attr_value(property, inst)
+        current_values = Array(value)
+
+        !current_values.any?{ |x| self.find_any?(target_values, x)}
+      end
+      def find_any?(array, value)
+        array.any?{ |x| self.class.equivalent_value?(value, x)}
+      end
+    end
+  end
+end