Added Arel::Nodes::NamedFunction for representing generic SQL functions

7 files changed, 47 insertions, 11 deletions

diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index c43134bb50..64f2cc13fd 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -28,6 +28,7 @@ require 'arel/nodes/and'
 require 'arel/nodes/function'
 require 'arel/nodes/count'
 require 'arel/nodes/values'
+require 'arel/nodes/named_function'
 
 # joins
 require 'arel/nodes/inner_join'
diff --git a/lib/arel/nodes/count.rb b/lib/arel/nodes/count.rb
index c6e19afb34..5c8ade1cf9 100644
--- a/lib/arel/nodes/count.rb
+++ b/lib/arel/nodes/count.rb
@@ -1,9 +1,6 @@
 module Arel
   module Nodes
     class Count < Arel::Nodes::Function
-
-      attr_accessor :distinct
-
       def initialize expr, distinct = false, aliaz = nil
         super(expr, aliaz)
         @distinct = distinct
diff --git a/lib/arel/nodes/function.rb b/lib/arel/nodes/function.rb
index e4e45bff31..b58eba7f38 100644
--- a/lib/arel/nodes/function.rb
+++ b/lib/arel/nodes/function.rb
@@ -2,11 +2,12 @@ module Arel
   module Nodes
     class Function < Arel::Nodes::Node
       include Arel::Expression
-      attr_accessor :expressions, :alias
+      attr_accessor :expressions, :alias, :distinct
 
       def initialize expr, aliaz = nil
         @expressions = expr
         @alias       = aliaz
+        @distinct    = false
       end
 
       def as aliaz
diff --git a/lib/arel/nodes/named_function.rb b/lib/arel/nodes/named_function.rb
new file mode 100644
index 0000000000..56669bf858
--- /dev/null
+++ b/lib/arel/nodes/named_function.rb
@@ -0,0 +1,12 @@
+module Arel
+  module Nodes
+    class NamedFunction < Arel::Nodes::Function
+      attr_accessor :name
+
+      def initialize name, expr, aliaz = nil
+        super(expr, aliaz)
+        @name = name
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/depth_first.rb b/lib/arel/visitors/depth_first.rb
index ed95cad472..914b2d1999 100644
--- a/lib/arel/visitors/depth_first.rb
+++ b/lib/arel/visitors/depth_first.rb
@@ -28,6 +28,7 @@ module Arel
       def function o
         visit o.expressions
         visit o.alias
+        visit o.distinct
       end
       alias :visit_Arel_Nodes_Avg    :function
       alias :visit_Arel_Nodes_Exists :function
@@ -35,6 +36,13 @@ module Arel
       alias :visit_Arel_Nodes_Min    :function
       alias :visit_Arel_Nodes_Sum    :function
 
+      def visit_Arel_Nodes_NamedFunction o
+        visit o.name
+        visit o.expressions
+        visit o.distinct
+        visit o.alias
+      end
+
       def visit_Arel_Nodes_Count o
         visit o.expressions
         visit o.alias
diff --git a/lib/arel/visitors/dot.rb b/lib/arel/visitors/dot.rb
index 3c4fe12d1f..92d05c7b67 100644
--- a/lib/arel/visitors/dot.rb
+++ b/lib/arel/visitors/dot.rb
@@ -38,13 +38,6 @@ module Arel
         visit_edge o, "relation"
       end
 
-      def visit_Arel_Nodes_Sum o
-        visit_edge o, "expressions"
-        visit_edge o, "alias"
-      end
-      alias :visit_Arel_Nodes_Max :visit_Arel_Nodes_Sum
-      alias :visit_Arel_Nodes_Avg :visit_Arel_Nodes_Sum
-
       def visit_Arel_Nodes_Count o
         visit_edge o, "expressions"
         visit_edge o, "distinct"
@@ -82,6 +75,24 @@ module Arel
       alias :visit_Arel_Nodes_Top               :unary
       alias :visit_Arel_Nodes_UnqualifiedColumn :unary
 
+      def function o
+        visit_edge o, "expressions"
+        visit_edge o, "distinct"
+        visit_edge o, "alias"
+      end
+      alias :visit_Arel_Nodes_Exists :function
+      alias :visit_Arel_Nodes_Min    :function
+      alias :visit_Arel_Nodes_Max    :function
+      alias :visit_Arel_Nodes_Avg    :function
+      alias :visit_Arel_Nodes_Sum    :function
+
+      def visit_Arel_Nodes_NamedFunction o
+        visit_edge o, "name"
+        visit_edge o, "expressions"
+        visit_edge o, "distinct"
+        visit_edge o, "alias"
+      end
+
       def visit_Arel_Nodes_InsertStatement o
         visit_edge o, "relation"
         visit_edge o, "columns"
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 4eae5a9ae5..d5534384f8 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -183,6 +183,12 @@ eowarn
         visit o.expr
       end
 
+      def visit_Arel_Nodes_NamedFunction o
+        "#{o.name}(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
+          visit x
+        }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
+      end
+
       def visit_Arel_Nodes_Count o
         "COUNT(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x|
           visit x