initial commit for collector implementation

lib/arel/collectors/sql_string.rb

@@ -0,0 +1,26 @@
+module Arel
+  module Collectors
+    class SQLString
+      def initialize
+        @str = ''
+      end
+
+      def value
+        @str
+      end
+
+      def << str
+        @str << str
+        self
+      end
+
+      def start;  self; end
+      def finish; self; end
+
+      def add_bind bind
+        self << bind
+        self
+      end
+    end
+  end
+end