The Hugs 98 User Manual

Copyright and License

The Hugs 98 system is Copyright © Mark P Jones, Alastair Reid, the Yale Haskell Group, and the OGI School of Science & Engineering at OHSU, 1994-2002, All rights reserved. It is distributed as free software under the license in the file "License", which is included in the distribution.

1  Introduction

Hugs 98 is a functional programming system based on Haskell 98, the de facto standard for non-strict functional programming languages. This manual should give you all the information that you need to start using Hugs. However, it is not a tutorial on either functional programming in general or on Haskell in particular.

The first two sections provide introductory material:

The remaining sections provide reference material, including:

Whether you are a beginner or a seasoned old-timer, we hope that you will enjoy working with Hugs, and that, if you will pardon the pun, you will use it to embrace functional programming!


The development of Hugs has benefited considerably from the feedback, suggestions, and bug reports provided by its users. There are too many people to name here, but thanks are due for all of their contributions. A special thank you also to our friends and colleagues at OGI, Yale, and elsewhere, for their input to the current release.