Chapter 1. Introduction

Previous versions of GHC (versions 5.02 and older) came with a set of libraries called the hslibs, also known as the Hugs-GHC libraries. These libraries are being phased out in favour of the new hierarchical libraries, but for the time being we still provide hslibs for backwards compatibility.

The status of each module in hslibs can be considered to have three possible values:


The module has moved to the hierarchical libraries, and its documentation (in this document) will report its new location.

Not moved

The module is waiting to be moved to the new hierarchical libraries, but it hasn't moved yet. Please continue to use it from its current hslibs package for the time being. The documentation for the module (if it had any) is still in place in this document.


The module is deprecated and should not be used. A deprecated module will be indicated as such in its documentation, along with an suggested alternative API.

1.1. Usage

If you're using hslibs with GHC[i], then you need to add -package p to the command line for each package from which you're using a module. See the section on packages in the User's Guide for an explanation of packages.