Fix #118 against 4-0-stable

Manifest.txt

@@ -22,7 +22,6 @@ lib/arel/factory_methods.rb
 lib/arel/insert_manager.rb
 lib/arel/math.rb
 lib/arel/nodes.rb
-lib/arel/nodes/and.rb
 lib/arel/nodes/ascending.rb
 lib/arel/nodes/binary.rb
 lib/arel/nodes/count.rb
@@ -39,6 +38,7 @@ lib/arel/nodes/inner_join.rb
 lib/arel/nodes/insert_statement.rb
 lib/arel/nodes/join_source.rb
 lib/arel/nodes/named_function.rb
+lib/arel/nodes/nary.rb
 lib/arel/nodes/node.rb
 lib/arel/nodes/outer_join.rb
 lib/arel/nodes/over.rb

lib/arel/nodes.rb

@@ -30,7 +30,7 @@
 require 'arel/nodes/over'
 
 # nary
-require 'arel/nodes/and'
+require 'arel/nodes/nary'
 
 # function
 # FIXME: Function + Alias can be rewritten as a Function and Alias node.

lib/arel/nodes/binary.rb

@@ -40,11 +40,6 @@ def eql? other
       Matches
       NotEqual
       NotIn
-      Or
-      Union
-      UnionAll
-      Intersect
-      Except
     }.each do |name|
       const_set name, Class.new(Binary)
     end

lib/arel/nodes/nary.rb

@@ -0,0 +1,64 @@
+module Arel
+  module Nodes
+    class Nary < Arel::Nodes::Node
+      attr_reader :children
+
+      def initialize children, right = nil
+        super()
+        unless Array === children
+          warn "(#{caller.first}) #{ self.class.to_s.sub(/.*::/, '').upcase } nodes should be created with a list"
+          children = [children, right]
+        end
+        @children = children
+      end
+
+      def initialize_copy other
+        super
+        @children = @children.map {|child| child.clone}
+      end
+
+      def left
+        children.first
+      end
+
+      def left= child
+        children[0] = child
+      end
+
+      def right
+        children[1]
+      end
+
+      def right= child
+        children[1] = child
+      end
+
+      def << child
+        children << child
+      end
+
+      def hash
+        children.hash
+      end
+
+      def eql? other
+        self.class == other.class &&
+          self.children == other.children
+      end
+      alias :== :eql?
+    end
+
+    %w{
+      And
+      Or
+      Union
+      UnionAll
+      Except
+      ExceptAll
+      Intersect
+      IntersectAll
+    }.each do |name|
+      const_set name, Class.new(Nary)
+    end
+  end
+end

lib/arel/nodes/node.rb

@@ -27,7 +27,7 @@ def not
       # Factory method to create a Nodes::Grouping node that has an Nodes::Or
       # node as a child.
       def or right
-        Nodes::Grouping.new Nodes::Or.new(self, right)
+        Nodes::Grouping.new Nodes::Or.new [self, right]
       end
 
       ###

lib/arel/nodes/select_statement.rb

@@ -6,6 +6,7 @@ class SelectStatement < Arel::Nodes::Node
 
       def initialize cores = [SelectCore.new]
         super()
+        cores = [ cores ] unless Array === cores
         @cores          = cores
         @orders         = []
         @limit          = nil

lib/arel/nodes/unary.rb

@@ -29,7 +29,6 @@ def eql? other
       Offset
       On
       Ordering
-      Top
       Lock
       DistinctOn
     }.each do |name|

lib/arel/predications.rb

@@ -73,11 +73,11 @@ def not_in other
         elsif other.exclude_end?
           left  = Nodes::LessThan.new(self, other.begin)
           right = Nodes::GreaterThanOrEqual.new(self, other.end)
-          Nodes::Or.new left, right
+          Nodes::Or.new [left, right]
         else
           left  = Nodes::LessThan.new(self, other.begin)
           right = Nodes::GreaterThan.new(self, other.end)
-          Nodes::Or.new left, right
+          Nodes::Or.new [left, right]
         end
       else
         Nodes::NotIn.new self, other
@@ -169,7 +169,7 @@ def lteq_all others
     def grouping_any method_id, others
       nodes = others.map {|expr| send(method_id, expr)}
       Nodes::Grouping.new nodes.inject { |memo,node|
-        Nodes::Or.new(memo, node)
+        Nodes::Or.new [memo, node]
       }
     end
 

lib/arel/select_manager.rb

@@ -2,11 +2,15 @@ module Arel
   class SelectManager < Arel::TreeManager
     include Arel::Crud
 
-    def initialize engine, table = nil
+    def initialize engine, table = nil, cores = nil
       super(engine)
-      @ast   = Nodes::SelectStatement.new
-      @ctx    = @ast.cores.last
-      from table
+      if cores
+        @ast = Nodes::SelectStatement.new cores
+      else
+        @ast = Nodes::SelectStatement.new
+      end
+      @ctx = @ast.cores.last
+      from table if table
     end
 
     def initialize_copy other
@@ -182,22 +186,15 @@ def where_sql
     end
 
     def union operation, other = nil
-      if other
-        node_class = Nodes.const_get("Union#{operation.to_s.capitalize}")
-      else
-        other = operation
-        node_class = Nodes::Union
-      end
-
-      node_class.new self.ast, other.ast
+      set_agreggation :union, operation, other
     end
 
-    def intersect other
-      Nodes::Intersect.new ast, other.ast
+    def intersect operation, other = nil
+      set_agreggation :intersect, operation, other
     end
 
-    def except other
-      Nodes::Except.new ast, other.ast
+    def except operation, other = nil
+      set_agreggation :except, operation, other
     end
     alias :minus :except
 
@@ -215,10 +212,8 @@ def with *subqueries
     def take limit
       if limit
         @ast.limit = Nodes::Limit.new(limit)
-        @ctx.top   = Nodes::Top.new(limit)
       else
         @ast.limit = nil
-        @ctx.top   = nil
       end
       self
     end
@@ -315,5 +310,20 @@ def collapse exprs, existing = nil
         create_and exprs
       end
     end
+
+    def set_agreggation operator, variant, others = nil
+      if others
+        variant = '' if operator.to_s == :distinct.to_s
+        node_class = Nodes.const_get("#{operator.to_s.capitalize}#{variant.to_s.capitalize}")
+      else
+        others = variant
+        node_class = Nodes.const_get("#{operator.to_s.capitalize}")
+      end
+
+      others = [others] unless Array === others
+      set_node = node_class.new([self.ast] + others.map{|o| o.ast})
+
+      SelectManager.new self.engine, nil, set_node
+    end
   end
 end

lib/arel/visitors/depth_first.rb

@@ -25,7 +25,6 @@ def unary o, a
       alias :visit_Arel_Nodes_Ordering          :unary
       alias :visit_Arel_Nodes_Ascending         :unary
       alias :visit_Arel_Nodes_Descending        :unary
-      alias :visit_Arel_Nodes_Top               :unary
       alias :visit_Arel_Nodes_UnqualifiedColumn :unary
 
       def function o, a
@@ -56,6 +55,7 @@ def nary o, a
         o.children.each { |child| visit child, a }
       end
       alias :visit_Arel_Nodes_And :nary
+      alias :visit_Arel_Nodes_Or  :nary
 
       def binary o, a
         visit o.left, a
@@ -78,7 +78,6 @@ def binary o, a
       alias :visit_Arel_Nodes_Matches            :binary
       alias :visit_Arel_Nodes_NotEqual           :binary
       alias :visit_Arel_Nodes_NotIn              :binary
-      alias :visit_Arel_Nodes_Or                 :binary
       alias :visit_Arel_Nodes_OuterJoin          :binary
       alias :visit_Arel_Nodes_TableAlias         :binary
       alias :visit_Arel_Nodes_Values             :binary

lib/arel/visitors/dot.rb

@@ -71,7 +71,6 @@ def unary o, a
       alias :visit_Arel_Nodes_Not               :unary
       alias :visit_Arel_Nodes_Offset            :unary
       alias :visit_Arel_Nodes_On                :unary
-      alias :visit_Arel_Nodes_Top               :unary
       alias :visit_Arel_Nodes_UnqualifiedColumn :unary
       alias :visit_Arel_Nodes_Preceding         :unary
       alias :visit_Arel_Nodes_Following         :unary
@@ -162,6 +161,7 @@ def nary o, a
         end
       end
       alias :visit_Arel_Nodes_And :nary
+      alias :visit_Arel_Nodes_Or  :nary
 
       def binary o, a
         visit_edge o, a, "left"
@@ -181,7 +181,6 @@ def binary o, a
       alias :visit_Arel_Nodes_Matches            :binary
       alias :visit_Arel_Nodes_NotEqual           :binary
       alias :visit_Arel_Nodes_NotIn              :binary
-      alias :visit_Arel_Nodes_Or                 :binary
       alias :visit_Arel_Nodes_Over               :binary
 
       def visit_String o, a

lib/arel/visitors/mssql.rb

@@ -3,13 +3,6 @@ module Visitors
     class MSSQL < Arel::Visitors::ToSql
       private
 
-      # `top` wouldn't really work here. I.e. User.select("distinct first_name").limit(10) would generate
-      # "select top 10 distinct first_name from users", which is invalid query! it should be
-      # "select distinct top 10 first_name from users"
-      def visit_Arel_Nodes_Top o, a
-        ""
-      end
-
       def visit_Arel_Nodes_SelectStatement o, a
         if !o.limit && !o.offset
           return super o, a

lib/arel/visitors/to_sql.rb

@@ -166,7 +166,7 @@ def visit_Arel_Nodes_SelectStatement o, a
           str << SPACE
         end
 
-        o.cores.each { |x| str << visit_Arel_Nodes_SelectCore(x, a) }
+        o.cores.each { |x| str << visit(x, a) }
 
         unless o.orders.empty?
           str << SPACE
@@ -256,19 +256,27 @@ def visit_Arel_Nodes_WithRecursive o, a
       end
 
       def visit_Arel_Nodes_Union o, a
-        "( #{visit o.left, a} UNION #{visit o.right, a} )"
+        "( #{ o.children.map { |x| visit x, a }.join ' ) UNION ( ' } )"
       end
 
       def visit_Arel_Nodes_UnionAll o, a
-        "( #{visit o.left, a} UNION ALL #{visit o.right, a} )"
+        "( #{ o.children.map { |x| visit x, a }.join ' ) UNION ALL ( ' } )"
       end
 
       def visit_Arel_Nodes_Intersect o, a
-        "( #{visit o.left, a} INTERSECT #{visit o.right, a} )"
+        "( #{ o.children.map { |x| visit x, a }.join ' ) INTERSECT ( ' } )"
+      end
+
+      def visit_Arel_Nodes_IntersectAll o, a
+        "( #{ o.children.map { |x| visit x, a }.join ' ) INTERSECT ALL ( ' } )"
       end
 
       def visit_Arel_Nodes_Except o, a
-        "( #{visit o.left, a} EXCEPT #{visit o.right, a} )"
+        "( #{ o.children.map { |x| visit x, a }.join ' ) EXCEPT ( ' } )"
+      end
+
+      def visit_Arel_Nodes_ExceptAll o, a
+        "( #{ o.children.map { |x| visit x, a }.join ' ) EXCEPT ALL ( ' } )"
       end
 
       def visit_Arel_Nodes_NamedWindow o, a
@@ -336,11 +344,6 @@ def visit_Arel_Nodes_Limit o, a
         "LIMIT #{visit o.expr, a}"
       end
 
-      # FIXME: this does nothing on most databases, but does on MSSQL
-      def visit_Arel_Nodes_Top o, a
-        ""
-      end
-
       def visit_Arel_Nodes_Lock o, a
         visit o.expr, a
       end
@@ -350,7 +353,7 @@ def visit_Arel_Nodes_Grouping o, a
       end
 
       def visit_Arel_SelectManager o, a
-        "(#{o.to_sql.rstrip})"
+        "( #{o.to_sql.rstrip} )"
       end
 
       def visit_Arel_Nodes_Ascending o, a
@@ -503,7 +506,7 @@ def visit_Arel_Nodes_And o, a
       end
 
       def visit_Arel_Nodes_Or o, a
-        "#{visit o.left, a} OR #{visit o.right, a}"
+        o.children.map { |x| visit x, a }.join ' OR '
       end
 
       def visit_Arel_Nodes_Assignment o, a