A two-level data transformation consists of a type-level transformation of a data format coupled with value-level transformations of data instances corresponding to that format. Examples of two-level data transformations include XML schema evolution coupled with document migration, and data mappings that couple a data format mapping with conversions between mapped formats.

This project provides a framework for two-level transformations and front-ends for several languages.

• Theory and Implementation in Haskell
• Documentation
• Credits