From 32fbb70f100d0d6f9800020ef519a09a0852ae47 Mon Sep 17 00:00:00 2001
From: Ernie Miller <ernie@metautonomo.us>
Date: Thu, 25 Mar 2010 20:18:36 -0400
Subject: Add grouped predicates (_any/_all) and refactored predication method
 definitions

---
 lib/arel/algebra/attributes/attribute.rb | 72 +++++++++++++++-----------------
 lib/arel/algebra/predicates.rb           | 26 ++++++++++++
 lib/arel/engines/sql/predicates.rb       | 18 ++++++++
 3 files changed, 78 insertions(+), 38 deletions(-)

(limited to 'lib')

diff --git a/lib/arel/algebra/attributes/attribute.rb b/lib/arel/algebra/attributes/attribute.rb
index d9ea588128..5689d69b02 100644
--- a/lib/arel/algebra/attributes/attribute.rb
+++ b/lib/arel/algebra/attributes/attribute.rb
@@ -82,48 +82,44 @@ module Arel
     include Congruence
 
     module Predications
-      def eq(other)
-        Predicates::Equality.new(self, other)
-      end
-
-      def not(other)
-        Predicates::Not.new(self, other)
-      end
-
-      def lt(other)
-        Predicates::LessThan.new(self, other)
-      end
-
-      def lteq(other)
-        Predicates::LessThanOrEqualTo.new(self, other)
-      end
-
-      def gt(other)
-        Predicates::GreaterThan.new(self, other)
-      end
-
-      def gteq(other)
-        Predicates::GreaterThanOrEqualTo.new(self, other)
-      end
-
-      def matches(regexp)
-        Predicates::Match.new(self, regexp)
-      end
-
-      def notmatches(regexp)
-        Predicates::NotMatch.new(self, regexp)
-      end
+      methods = {
+        :eq => "Equality",
+        :not => "Not",
+        :lt => "LessThan",
+        :lteq => "LessThanOrEqualTo",
+        :gt => "GreaterThan",
+        :gteq => "GreaterThanOrEqualTo",
+        :matches => "Match",
+        :notmatches => "NotMatch",
+        :in => "In",
+        :notin => "NotIn"
+      }
       
-      def in(array)
-        if array.is_a?(Range) && array.exclude_end?
-          [Predicates::GreaterThanOrEqualTo.new(self, array.begin), Predicates::LessThan.new(self, array.end)]
-        else
-          Predicates::In.new(self, array)
+      def self.predication(name, klass)
+        methods = {
+          :operator => "
+            def #{name}(other)
+              Predicates::#{klass}.new(self, other)
+            end
+          ",
+          :any => "
+            def #{name}_any(*others)
+              Predicates::Any.new(Predicates::#{klass}, self, *others)
+            end
+          ",
+          :all => "
+            def #{name}_all(*others)
+              Predicates::All.new(Predicates::#{klass}, self, *others)
+            end
+          "
+        }
+        [:operator, :any, :all].each do |method_name|
+          module_eval methods[method_name], __FILE__, __LINE__
         end
       end
       
-      def notin(array)
-        Predicates::NotIn.new(self, array)
+      methods.each_pair do |method_name, class_name|
+        predication(method_name, class_name)
       end
     end
     include Predications
diff --git a/lib/arel/algebra/predicates.rb b/lib/arel/algebra/predicates.rb
index 05a1de983d..ea1f771abb 100644
--- a/lib/arel/algebra/predicates.rb
+++ b/lib/arel/algebra/predicates.rb
@@ -9,6 +9,32 @@ module Arel
         And.new(self, other_predicate)
       end
     end
+    
+    class Grouped < Predicate
+      attributes :operator, :operand1, :operands2
+      
+      def initialize(operator, operand1, *operands2)
+        @operator = operator
+        @operand1 = operand1
+        @operands2 = operands2.uniq
+      end
+      
+      def ==(other)
+        self.class === other          and
+        @operand1  ==  other.operand1 and
+        same_elements?(@operands2, other.operands2)
+      end
+      
+      private
+      
+      def same_elements?(a1, a2)
+        [:select, :inject, :size].each do |m|
+          return false unless [a1, a2].each {|a| a.respond_to?(m) }
+        end
+        a1.inject({}) { |h,e| h[e] = a1.select { |i| i == e }.size; h } ==
+        a2.inject({}) { |h,e| h[e] = a2.select { |i| i == e }.size; h }
+      end
+    end
 
     class Binary < Predicate
       attributes :operand1, :operand2
diff --git a/lib/arel/engines/sql/predicates.rb b/lib/arel/engines/sql/predicates.rb
index e9a068fb13..53bac7a2ca 100644
--- a/lib/arel/engines/sql/predicates.rb
+++ b/lib/arel/engines/sql/predicates.rb
@@ -19,6 +19,24 @@ module Arel
     class And < CompoundPredicate
       def predicate_sql; "AND" end
     end
+    
+    class GroupedPredicate < Grouped
+      def to_sql(formatter = nil)
+        "(" + 
+          operands2.inject([]) { |predicates, operand|
+            predicates << operator.new(operand1, operand).to_sql
+          }.join(" #{predicate_sql} ") +
+        ")"
+      end
+    end
+    
+    class Any < GroupedPredicate
+      def predicate_sql; "OR" end
+    end
+    
+    class All < GroupedPredicate
+      def predicate_sql; "AND" end
+    end
 
     class Equality < Binary
       def predicate_sql
-- 
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