This note is meant to give people who are familiar with the \gls{FP} language \gls{HASKELL} a consise overview of \gls{CLEAN} language elements and how they differ from \gls{HASKELL}.
The goal is to support the reader when reading \gls{CLEAN} code.
-Table~\ref{tbl:syn_clean_haskell} shows frequently occuring \gls{CLEAN} language elements on the left side and their \gls{HASKELL} equivalent on the right side.
+\Cref{tbl:syn_clean_haskell} shows frequently occuring \gls{CLEAN} language elements on the left side and their \gls{HASKELL} equivalent on the right side.
Obviously, this summary is not exhaustive.
Some \gls{CLEAN} language elements that are not easily translatable to \gls{HASKELL} and thus do not occur in the summary following below.
We hope you enjoy these notes and that it aids you in reading \gls{CLEAN} programs.
%:: T = T (Int -> *(*World -> *World)) // Writing :: T = T (Int *World -> *World) won't work
\subsection{Expressions}
-Patterns in \gls{CLEAN} can be used as predicates as well~\citep[Chp.~3.4.3]{plasmeijer_clean_2021}.
+Patterns in \gls{CLEAN} can be used as predicates as well~\citep[\citesection{3.4.3}]{plasmeijer_clean_2021}.
Using the \cleaninline{=:} operator, a value can be tested against a pattern.
Variable names are not allowed but wildcard patterns \cleaninline{\_} are.
Due to the nature of uniqueness typing, many functions in \gls{CLEAN} are state transition functions with possibly unique states.
The \emph{let before} construct allows the programmer to specify sequential actions without having to invent unique names for the different versions of the state.
-\Cref{lst:let_before} shows an example of the usage of the \emph{let before} construct (adapted from~\citep[Chp.~3.5.4]{plasmeijer_clean_2021}).
+\Cref{lst:let_before} shows an example of the usage of the \emph{let before} construct (adapted from~\citep[\citesection{3.5.4}]{plasmeijer_clean_2021}).
\begin{lstClean}[label={lst:let_before},caption={Let before expression example.}]
readChars :: *File -> ([Char], *File)
\end{lstClean}
\subsection{Generics}
-Polytypic functions~\citep{jeuring_polytypic_1996}---also known as generic or kind-indexed fuctions---are built into \gls{CLEAN}~\citep[Chp.~7.1]{plasmeijer_clean_2021}\citep{alimarine_generic_2005} whereas in \gls{HASKELL} they are implemented as a library~\citep[Chp.~6.19.1]{ghc_team_ghc_2021}.
+Polytypic functions~\citep{jeuring_polytypic_1996}---also known as generic or kind-indexed fuctions---are built into \gls{CLEAN}~\citep[\citesection{7.1}]{plasmeijer_clean_2021}\citep{alimarine_generic_2005} whereas in \gls{HASKELL} they are implemented as a library~\citep[\citesection{6.19.1}]{ghc_team_ghc_2021}.
The implementation of generics in \gls{CLEAN} is very similar to that of Generic H$\forall$skell~\citep{hinze_generic_2003}.
%When calling a generic function, the kind must always be specified and depending on the kind, the function may require more arguments.
\subsection{\texorpdfstring{\glsentrytext{GADT}}{GADT}s}
\Glspl{GADT} are enriched data types that allow the type instantiation of the constructor to be explicitly defined~\citep{cheney_first-class_2003,hinze_fun_2003}.
-While \glspl{GADT} are not natively supported in \gls{CLEAN}, they can be simulated using embedding-projection pairs or equivalence types~\citep[Sec.~2.2]{cheney_lightweight_2002}.
+While \glspl{GADT} are not natively supported in \gls{CLEAN}, they can be simulated using embedding-projection pairs or equivalence types~\citep[\citesection{2.2}]{cheney_lightweight_2002}.
To illustrate this, \cref{lst:gadt_clean} shows an example \gls{GADT} that would be implemented in \gls{HASKELL} as done in \cref{lst:gadt_haskell}\requiresGHCmod{GADTs}.
\lstinputlisting[language=Clean,firstline=4,lastline=24,label={lst:gadt_clean},caption={Expression \gls{GADT} using equivalence types in \gls{CLEAN}.}]{lst/expr_gadt.icl}