Chapter 7. Hugs-specific language extensions

These experimental features are unique to Hugs. Except of the debugging primitives, they require the -98 option.

7.1. Typed records with extensibility

Trex is a very powerful and flexible record system. See Section 7.2 of the Hugs 98 User Manual for details.

To use equality and show on extensible records, a module must import Hugs.Trex. This module also defines an empty record value and type:

emptyRec :: Rec EmptyRow