Polytypic Data Conversion Programs
Patrik Jansson and
Several generic programs for converting values from regular datatypes
to some other format, together with their corresponding inverses, are
Among the formats considered are shape plus contents, compact bit
streams and pretty printed strings.
The different data conversion programs are constructed using John
Hughes' arrow combinators along with a proof that printing (from a
regular datatype to another format) followed by parsing (from that
format back to the regular datatype) is the identity.
The printers and parsers are described in
a polytypic extension of the functional language Haskell.
The implementation of Show and Read as Haskell and PolyP code can be
browsed or downloaded.
Last modified: Mon Feb 26 10:06:20 MET 2001
Patrik Jansson /