Chapter 6. Hugs-specific language extensions

Table of Contents
Typed extensible records
Restricted type synonyms
Here documents
Hugs debugging primitives

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

Typed extensible records

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