:- module pprint.
:- interface.
:- import_module char.
:- import_module io.
:- import_module list.
:- import_module stream.
:- import_module string.
:- import_module univ.
:- type doc.
:- typeclass doc(T).
:- instance (pprint.doc(char.char)).
:- instance (pprint.doc(pprint.doc)).
:- instance (pprint.doc(int)).
:- instance (pprint.doc(float)).
:- instance (pprint.doc(string)).
