With this library you can define record field accessors which allow
 setting, getting and modifying values easily. You can combine accessors
 of a record and sub-records to make the access look like the fields
 of the sub-record belong to the main record.
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.