Outputable is:exact
This module defines classes and functions for pretty-printing. It also
exports a number of helpful debugging and other utilities such as
trace and
panic.
The interface to this module is very similar to the standard Hughes-PJ
pretty printing module, except that it exports a number of additional
functions that are rarely used, and works over the
SDoc type.
Class designating that some type has an
SDoc representation
Values that can be output.
Class designating that some type has an
SDoc representation