--- /dev/null
+\usepackage{listings}
+
+\lstdefinelanguage{Clean}{%
+ alsoletter={ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_`1234567890},
+ alsoletter={~!@\#$\%^\&*-+=?<>:|\\.},
+ morekeywords={generic,implementation,definition,dynamic,module,import,from,where,in,of,case,let,infix,infixr,infixl,class,instance,with,if,derive,Void},
+ sensitive=true,
+ morecomment=[l]{//},
+ morecomment=[n]{/*}{*/},
+ morestring=[b]",
+ morestring=[b]',
+ emptylines=1,
+ basicstyle=\small,
+ identifierstyle=\small\ttfamily,
+ commentstyle=\itshape,
+ keywordstyle=\bfseries,
+ stringstyle=\ttfamily,
+ numbers=none,
+ showstringspaces=false,
+ basewidth=0.45em,
+ columns=[c]fixed,
+ keepspaces=true,
+ breaklines=false,
+ tabsize=4,
+ texcl=true,
+ escapeinside={(\#}{\#)},
+ literate=%
+ % Basic Clean constructs
+ {\\}{{$\lambda\:$}}1
+ {A.}{{$\forall\;\,$}}1
+ {E.}{{$\exists\;\,$}}1
+ {>}{{$>$}}1
+ {<}{{$<$}}1
+ {<=}{{$\leq$}}1
+ {>=}{{$\geq$}}1
+ {<>}{{$\neq$}}1
+ {->}{{$\rightarrow$}}2
+ {<-}{{$\leftarrow$}}1
+ {=}{{$=$}}1
+ {~}{{$\sim$}}1
+ {\#}{{$\sharp$}}1
+ {\{|}{{$\{\!|\!$}}1
+ {|\}}{{$\!|\!\}$}}1
+ {:=}{{$:=$}}2
+ {==}{{$==$}}2
+ {++}{{$+\!\!+$}}2
+ {+++}{{$+\!\!\!\!+\!\!\!\!+$}}2
+ {:==}{{$:==$}}3
+ {\{|*|\}}{{$\{\!|\!\!\star\!\!|\!\}$}}3
+ %
+ % Basic iTask constructs
+ {>||>}{{$\triangleright\triangleright$}}2
+ {>>=}{{\texttt{>>=}}}3
+ {>>|}{{\texttt{>>|}}}3
+ {?>>}{{\texttt{?>>}}}3
+ {!>>}{{\texttt{!>>}}}3
+ {-||-}{{\texttt{-||-}}}4
+ {.||.}{{\texttt{.||.}}}4
+ {.&&.}{{\texttt{.\&\&.}}}4
+}
+
+\newcommand{\CleanInline}[1]{\lstinline[language=Clean]¦#1¦}
+\newcommand{\CI}[1]{\CleanInline{#1}}
+
+\lstdefinestyle{numbers}{numbers=left, stepnumber=1, numberstyle=\tiny, numbersep=5pt}
+
+\lstnewenvironment{CleanCode}{\lstset{language=Clean,identifierstyle=\ttfamily}}{}
+\lstnewenvironment{CleanCodeN}{\lstset{language=Clean,style=numbers}}{}
+\lstnewenvironment{CleanCodeB}{\lstset{language=Clean,frame=single}}{}
+\lstnewenvironment{CleanCodeNB}{\lstset{language=Clean,style=numbers,frame=single}}{}
\section{Introduction}
\begin{frame}
\frametitle{Scientific Impact}
- \begin{itemize}
- \item Cited $676$ times in $23$ years
- \item $\pm 30$ cites per year
- \item Cited as de-facto monad introducing paper
- \item Monads in computer science: Moggi et al.\ in $1989$
- \end{itemize}
+ \begin{block}{Metrics}
+ \begin{itemize}[<+->]
+ \item Cited $676$ times in $23$ years
+ \item $\pm 30$ cites per year
+ \item Cited as de-facto monad introducing paper
+ \item Monads in computer science: Moggi et al.\ in $1989$
+ \end{itemize}
+ \end{block}
\end{frame}
\begin{frame}
\pause%
\begin{block}{Current state of the art}
- \begin{itemize}
+ \begin{itemize}[<+->]
\item $2016$: $2$ papers citing Wadler
\item $2015$: $24$ papers citing Wadler
\item Ranging from
- \pause%
- \begin{itemize}
+ \begin{itemize}[<+->]
\item Introducing new monad types
\item Generic programming
\item Designing modular DSL's
\item Concurrency frameworks in functional languages
+ \item\ldots
\end{itemize}
\end{itemize}
\end{block}
\end{frame}
\section{Contents}
+\subsection{Introduction}
+\begin{frame}
+ \frametitle{Introduction}
+ \begin{itemize}
+ \item Monads (Moggi et al.)
+ \item Integrate the impure in the pure
+ \item Wadler shows \textsc{Haskell} examples
+ \item Following samples are in \textsc{Clean}
+ \end{itemize}
+\end{frame}
+
+\subsection{Naive approach}
+\begin{frame}[fragile]
+ \frametitle{Case study (1)}
+ \framesubtitle{Evaluator}
+ \begin{CleanCode}
+:: Term = Con Int | Div Term Term
+
+eval :: Term -> Int
+eval (Con a) = a
+eval (Div t u) = eval t / eval u
+
+//Examples
+answer :: Term
+answer = (Div (Div (Con 1972) (Con 2)) (Con 23))
+
+error :: Term
+error = (Div (Con 1) (Con 0))
+ \end{CleanCode}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Case study (2)}
+ \framesubtitle{Exceptions}
+ \begin{CleanCode}
+:: M a = Raise Exception | Return a
+:: Exception :== String
+
+eval :: Term -> M Int
+eval (Con a) = Return a
+eval (Div t u) = case eval t of
+ Raise e = Raise e
+ Return a = case eval u of
+ Raise e = Raise e
+ Return b = if (b == 0)
+ (Raise "Divide by zero")
+ (Return (a / b))
+ \end{CleanCode}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Case study (3)}
+ \framesubtitle{State, count divisions}
+ \begin{CleanCode}
+:: M a :== State -> (a, State)
+:: State :== Int
+
+eval :: Term -> M Int
+eval (Con a) x = (a, x)
+eval (Div t u)
+# (a, y) = eval t x
+# (b, z) = eval u y
+= (a/b, z+1)
+ \end{CleanCode}
+\end{frame}
+
+\subsection{Monadic approach}
+\begin{frame}[fragile]
+ \frametitle{Monadic (1)}
+ Monad is a triple: $(M, unit, \star)$
+ \pause%
+ \begin{block}{Signatures}
+ \begin{CleanCode}
+:: M a = ...
+unit :: a -> M a
+((#$\star$#)) :: (M a) (a -> M b) -> M b
+ \end{CleanCode}
+ \end{block}
+ \pause%
+ \begin{block}{Evaluator (Identity monad)}
+ \begin{CleanCode}
+:: M a :== a
+unit :: a -> I a
+unit a = a
+((#$\star$#)) :: (M a) (a -> M b) -> M b
+a (#$\star$#) k = k a
+ \end{CleanCode}
+ \end{block}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Monadic (2)}
+ \framesubtitle{Exceptions}
+ \pause%
+ \begin{CleanCode}
+:: M a = Raise Exception | Return a
+:: Exception :== String
+ \end{CleanCode}
+ \pause%
+ \begin{CleanCode}
+unit :: a -> M a
+unit a = Return a
+
+((#$\star$#)) :: (M a) (a -> M b) -> M b
+m (#$\star$#) k = case m of
+ Raise e = Raise e
+ Return a = k a
+ \end{CleanCode}
+ \pause%
+ \begin{CleanCode}
+raise :: Exception -> M a
+raise e = Raise e
+ \end{CleanCode}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Monadic (3)}
+ \framesubtitle{State}
+ \pause%
+ \begin{CleanCode}
+:: M a = State -> (a, State)
+:: State :== Int
+ \end{CleanCode}
+ \pause%
+ \begin{CleanCode}
+unit :: a -> M a
+unit a = \x.(a, x)
+
+((#$\star$#)) :: (M a) (a -> M b) -> M b
+m (#$\star$#) k = \x.let (a, y) = m x in
+ let (b, z) = k a y in
+ (b, z)
+ \end{CleanCode}
+ \pause%
+ \begin{CleanCode}
+tick :: M Void
+tick = \x.(Void, x + 1)
+ \end{CleanCode}
+\end{frame}
+
+\subsection{Laws}
+\begin{frame}[fragile]
+ \frametitle{Laws}
+ \begin{block}{Monoid}
+ \begin{itemize}
+ \item Left unit:
+ \begin{CleanCode}
+unit a (#$\star$#) \b.n = n[a/b]
+ \end{CleanCode}
+ \item Right unit
+ \begin{CleanCode}
+m (#$\star$#) \a.unit a = m
+ \end{CleanCode}
+ \item Associativity
+ \begin{CleanCode}
+m (#$\star$#) (\a.n (#$\star$#) \b.o) = (m (#$\star$#) \a.n) (#$\star$#) \b.o
+ \end{CleanCode}
+ \end{itemize}
+ \end{block}
+\end{frame}
+
+\subsection{Further evidence}
+\begin{frame}[fragile]
+ \frametitle{Further examples}
+ \begin{itemize}[<+->]
+ \item Array %TODO
+ \end{itemize}
+\end{frame}
\section{Discussion}
+\begin{frame}
+\end{frame}
\end{document}
repositories / rsss1516.git / commitdiff