Improve syntax for sifters -- can now be appended to keypaths

lib/squeel/nodes/join.rb

@@ -34,6 +34,11 @@ def polymorphic?
         _klass
       end
 
+      # Implemented for equality testing
+      def hash
+        [_name, _type, _klass].hash
+      end
+
       # Compare with other objects
       def eql?(other)
         self.class.eql?(other.class) &&

lib/squeel/nodes/key_path.rb

@@ -109,7 +109,21 @@ def /(other)
       # @param other The right hand side of the operation
       # @return [Operation] An operation with the given custom operator, the KeyPath on its left and the other object on the right.
       def op(operator, other)
-        endpoint.respond_to?(:op) ? super : no_method_error(:/)
+        endpoint.respond_to?(:op) ? super : no_method_error(:op)
+      end
+
+      # Allow KeyPath to have a sifter as its endpoint, if the endpoint is a
+      # chainable node (Stub or Join)
+      # @param [Symbol] name The name of the sifter
+      # @return [KeyPath] This keypath, with a sifter as its endpoint
+      def sift(name, *args)
+        if Stub === endpoint || Join === endpoint
+          @path << endpoint
+          @endpoint = Sifter.new(name, args)
+          self
+        else
+          no_method_error :sift
+        end
       end
 
       # Set the absolute flag on this KeyPath

lib/squeel/nodes/sifter.rb

@@ -9,6 +9,19 @@ def initialize(name, args)
         @name, @args = name, args
       end
 
+      # Implemented for equality testing
+      def hash
+        [name, args].hash
+      end
+
+      # Compare with other objects
+      def eql?(other)
+        self.class.eql?(other.class) &&
+        self.name.eql?(other.name) &&
+        self.args.eql?(other.args)
+      end
+      alias :== :eql?
+
     end
   end
 end

lib/squeel/nodes/stub.rb

@@ -108,6 +108,12 @@ def inner
         Join.new(self.symbol, Arel::InnerJoin)
       end
 
+      # Create a keypath with a sifter as its endpoint
+      # @return [KeyPath] The new KeyPath
+      def sift(name, *args)
+        KeyPath.new(self, Sifter.new(name, args))
+      end
+
       # Create an outer Join node for the association named by this Stub
       # @return [Join] The new outer Join node
       def outer

lib/squeel/version.rb

@@ -1,3 +1,3 @@
 module Squeel
-  VERSION = "0.9.1"
+  VERSION = "0.9.2"
 end

spec/squeel/nodes/key_path_spec.rb

@@ -55,6 +55,12 @@ module Nodes
         as.right.should eq 'other_name'
       end
 
+      it 'creates sifter nodes with #sift' do
+        @k.sift(:blah, 1)
+        sifter = @k.endpoint
+        sifter.should be_a Sifter
+      end
+
       it 'creates AND nodes with & if the endpoint responds to &' do
         node = @k.third.fourth.eq('Bob') & Stub.new(:attr).eq('Joe')
         node.should be_a And

spec/squeel/nodes/stub_spec.rb

@@ -39,6 +39,12 @@ module Nodes
         keypath.path_with_endpoint.should eq [@s, Join.new(:another, Arel::InnerJoin, Person)]
       end
 
+      it 'creates a KeyPath with a sifter endpoint when sent #sift' do
+        keypath = @s.sift(:blah, 1)
+        keypath.should be_a KeyPath
+        keypath.path_with_endpoint.should eq [@s, Sifter.new(:blah, [1])]
+      end
+
       it 'creates an absolute keypath with just an endpoint with ~' do
         node = ~@s
         node.should be_a KeyPath

spec/squeel/visitors/predicate_visitor_spec.rb

@@ -272,6 +272,15 @@ module Visitors
         expr.right.to_sql.should match /"children_people"."name" LIKE '%smith'/
       end
 
+      it 'visits sifters in a keypath' do
+        predicate = @v.accept(dsl {children.sift(:name_starts_or_ends_with, 'smith')})
+        predicate.should be_a Arel::Nodes::Grouping
+        expr = predicate.expr
+        expr.should be_a Arel::Nodes::Or
+        expr.left.to_sql.should match /"children_people"."name" LIKE 'smith%'/
+        expr.right.to_sql.should match /"children_people"."name" LIKE '%smith'/
+      end
+
       it 'honors an explicit table in string keys' do
         predicate = @v.accept('things.attribute' => 'retro')
         predicate.should be_a Arel::Nodes::Equality