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-rw-r--r--lib/arel/algebra/relations/row.rb21
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/arel/algebra/relations/row.rb b/lib/arel/algebra/relations/row.rb
new file mode 100644
index 0000000000..2d63498452
--- /dev/null
+++ b/lib/arel/algebra/relations/row.rb
@@ -0,0 +1,21 @@
+module Arel
+ class Row
+ attributes :relation, :tuple
+ deriving :==, :initialize
+
+ def [](attribute)
+ tuple[relation.position_of(attribute)]
+ end
+
+ def slice(*attributes)
+ Row.new(relation, attributes.inject([]) do |cheese, attribute|
+ cheese << self[attribute]
+ cheese
+ end)
+ end
+
+ def bind(relation)
+ Row.new(relation, tuple)
+ end
+ end
+end \ No newline at end of file