typeparamintro.tex

\section{Introduction}

In this chapter, we will introduce an extension of the fixed point
view on datatypes to be able to represent datatypes with type
parameters. We will start by introducing a simple functor
representation of datatypes using fixed points (Section
\ref{sec:functorrep}). We will then add support for a single type
parameter by extending the functors with an extra type parameter
(Section \ref{sec:oneparam}). In the following Section
(\ref{sec:multiparam}) we will introduce our extension, which allows
us to represent datatypes with an arbitrary number of type parameters.

After an introduction to the approach to represent mutually recursive
datatypes generically in the fixed point view \cite{multirec} as used
in the `multirec' library (Section \ref{sec:multirec}), we will show
how this approach has to be adapted (without changing its
functionality) to be able to incorporate our extension with type
parameters. Finally, we will add this extension, and show examples of
its use (Section \ref{sec:multirecparams}).