path: root/cloogle.tex

\documentclass{beamer}

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\title[Cloogle]{\texorpdfstring{\includegraphics[width=5em]{logo}}{Cloogle}}
\subtitle{A programming language search engine and its applications}
\author[Camil Staps]{\texorpdfstring{Camil Staps\\[1em]\footnotesize\mailto{camil@cloogle.org}}{Camil Staps}}
\date{January 5\textsuperscript{th}, 2018}

\usetheme{CambridgeUS}
\usecolortheme{cloogle}
\useinnertheme{circles}
\setbeamertemplate{itemize item}[triangle]
\setbeamertemplate{itemize subitem}[circle]

\usepackage[british]{babel}
\usepackage{csquotes}

\usepackage{tikz}
\usepackage{clooglearch}

\usepackage{minted}
\setminted{fontsize=\small}

% https://tex.stackexchange.com/a/23522/23992
\def\imagetop#1{\vtop{\null\hbox{#1}}}

\AtBeginSubsection[]{%
	\begin{frame}
		\frametitle{Table of Contents}
		\tableofcontents[currentsection,currentsubsection]
	\end{frame}}

\begin{document}

\maketitle

\section{Background}
\subsection{Why build a search engine?}
\begin{frame}[fragile]{Background}
	\begin{itemize}[<+->]
		\item
			What is wrong with this code?

			\begin{minted}[gobble=4]{clean}
				incAll :: [Int] -> [Int]
				incAll []     = []
				incAll [x:xs] = [x+1:incAll xs]
			\end{minted}

		\item
			Better:
			\begin{minted}[gobble=4]{clean}
				incAll = map ((+) 1)
			\end{minted}
	\end{itemize}
\end{frame}
\begin{frame}{Background}
	Lack of abstraction due to...

	\begin{itemize}
		\item Poor conceptualisation of the programmer?
		\pause
		\item Poor knowledge of the standard libraries?

			\medskip
			\quad\enquote{There is this function \texttt{map}, but where is it defined?}
	\end{itemize}

	\pause
	Solution: build a search engine!
\end{frame}

\section{Functionality}
\subsection{Overview}
\begin{frame}{Functionality}
	\centering
	\begin{tabular}{l l}
		\imagetop{\includegraphics[width=.45\textwidth]{scrot-search-name}} & \pause
		\imagetop{\includegraphics[width=.45\textwidth]{scrot-search-unify}} \pause\\
		\imagetop{\includegraphics[width=.45\textwidth]{scrot-search-typedef}} \pause&
		\imagetop{\includegraphics[width=.45\textwidth]{scrot-search-class}}
	\end{tabular}
\end{frame}

\subsection{Efficient unification search}
\begin{frame}{Efficient unification search}
	\begin{itemize}[<+->]
		\item With $\pm15,000$ functions, brute force unification search takes too long
		\item Grouping types together still gives $\pm13,000$ unique types
		\item If type $t$ generalises $u$, any $v$ that unifies with $u$ will also unify with $t$
			\begin{itemize}
				\item Conversely, if $v$ does not unify with $t$ it will not unify with $u$
			\end{itemize}
		\item This gives a partial order on types:

			\begin{center}
				\begin{tikzpicture}[level distance=2em]
					\tikzstyle{level 1}=[sibling distance=14em]
					\tikzstyle{level 2}=[sibling distance=7em]
					\tikzstyle{level 3}=[sibling distance=2em]
					\node {$a$}
						child {node {$a \rightarrow b$}
							child {node {$Int \rightarrow m~a$} child {node {\vdots}}}
							child {node {$a~a \rightarrow a$} child {node {\vdots}} child {node {\vdots}}}}
						child {node {$f~Real$}
							child {node {$Maybe~Real$}}
							child {node {$Either~a~Real$} child {node {\vdots}}}};
				\end{tikzpicture}
			\end{center}

		\item Early pruning speeds up unification search with a factor of $2-3$!
	\end{itemize}
\end{frame}

\begin{frame}[shrink]{Efficient unification search}
	\begin{itemize}[<+->]
		\item I would show the full tree, but didn't find a viewer that wouldn't crash
		\item Here is a detail of the tree for 5,000 functions:

			\medskip
			\begin{center}
				\includegraphics[width=\textwidth]{typetree-detail}
			\end{center}
	\end{itemize}
\end{frame}

\section{Architecture}
\subsection{Overview}
\begin{frame}{Architecture}
	\centering
	\footnotesize
	\begin{tikzpicture}[every node/.style={draw,block}]
		\useasboundingbox (-5,-4) rectangle (3.5,4);
		\only<1->\tikzsource
		\only<2->\tikzbuilddb
		\only<3->\tikzbackend
		\only<4->\tikzcache
		\only<5->\tikzfrontend
		\only<6->\tikzfrontendsrc
		\only<7->\tikzstats
		\only<8->\tikzclientA
		\only<9->\tikzclientB
		\only<10->\tikzclientC
		\only<11->\tikzclientD
		\only<12->\tikzclientE
	\end{tikzpicture}
\end{frame}

\subsection{Running locally: cloogle-tags}
\begin{frame}[fragile]{What if we want to run Cloogle locally?}
	\begin{itemize}
		\item Most common use case: finding definitions in personal libraries
		\pause
		\item Many editors support \emph{tagfiles}:

			\begin{minted}[gobble=4]{text}
				drop    StdList.dcl    46
				fopen   StdFile.dcl    27
				...
			\end{minted}
	\end{itemize}
\end{frame}
\begin{frame}{Running locally: old architecture}
	\centering
	\footnotesize
	\begin{tikzpicture}[every node/.style={draw,block}]
		\useasboundingbox (-5,-4) rectangle (3.5,4);
		\tikzsource
		\tikzbuilddb
		\tikzbackend
		\tikzcache
		\tikzfrontend
		\tikzfrontendsrc
		\tikzstats
		\tikzclientA
		\tikzclientB
		\tikzclientC
		\tikzclientD
		\tikzclientE
	\end{tikzpicture}
\end{frame}
\begin{frame}{Running locally: new architecture}
	\centering
	\footnotesize
	\begin{tikzpicture}[every node/.style={draw,block}]
		\useasboundingbox (-5,-4) rectangle (3.5,4);
		\tikzsource
		\tikzbuilddb
		\only<1>{%
			\tikzbackend[1]
			\tikzcache[1]
			\tikzfrontend[1]
			\tikzfrontendsrc[1]
			\tikzstats[1]
			\tikzclientA
			\tikzclientB
			\tikzclientC
			\tikzclientD
			\tikzclientE}
		\only<2->{%
			\tikzbackend[2]
			\tikzcache[2]
			\tikzfrontend[2]
			\tikzfrontendsrc[2]
			\tikzstats[2]
			\tikzclientB[2]
			\tikzclientC[2]
			\tikzclientD[2]
			\tikzclientE[2]
			\tikzcloogletags}
		\only<2>{\tikzclientA[2]}
		\only<3>{\tikzclientA[3]}
		\only<4>{\tikzclientA[4]}
	\end{tikzpicture}
\end{frame}

\section*{The end}

\subsection*{Discussion}
\begin{frame}[fragile]{Discussion}
	\begin{itemize}[<+->]
		\item The first generation of students was very enthusiastic
			\begin{itemize}
				\item The second not so much...
				\item But statistics show they used it more and more during the course
			\end{itemize}

		\item Unification search has some issues: you will never find

			\begin{minted}[gobble=4]{clean}
				fopen :: String Int *f -> (Bool, *File, *f)
			\end{minted}

			\begin{itemize}
				\item But a unifier gives useful information, like required instances
				\item Unification allows for optimisations that a distance measure does not
			\end{itemize}

		\item It's not just about search: indexing code has many use cases!

			\begin{itemize}
				\item Jumping to definitions (tagfiles)
				\item Automatic imports (vim-clean)
				\item Type-based code completion?
			\end{itemize}
	\end{itemize}
\end{frame}

\subsection*{Acknowledgements}
\begin{frame}[shrink]{Acknowledgements}
	Cloogle was conceived and built by:

	\begin{itemize}
		\item Camil Staps
		\item Mart Lubbers
	\end{itemize}

	With contributions by:

	\begin{itemize}
		\item Erin van der Veen
		\item Koen Dercksen
	\end{itemize}

	Using:

	\begin{itemize}
		\item The Clean compiler (the Clean team)
	\end{itemize}

	With thanks to:

	\begin{itemize}
		\item All users, for new ideas and bug reports (explicitly or in the query log)
	\end{itemize}

	Authors of clients:

	\begin{itemize}
		\item CLI app: Koen Dercksen
		\item IRC bot: Mart Lubbers
		\item vim-clean integration, Telegram bot, email client: Camil Staps
		\item Visual Studio Code plugin: Lucas Franceschino
	\end{itemize}
\end{frame}

\appendix
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\section{Appendices}

\begin{frame}
	\frametitle{Appendices}
	\tableofcontents[currentsection]
\end{frame}

\subsection{Can I use Cloogle for language X?}
\begin{frame}{Can I use Cloogle for language X?}
	\begin{itemize}
		\item It will work best on a language with the Hindley-Milner type system
			\begin{itemize}
				\item It can still be useful to less strongly typed languages
				\item It would be interesting to develop a search engine for dependent types
			\end{itemize}
		\item The search system is language-agnostic, but you need a tool to index source code into our JSON format
		\item Also see: \https{neilmitchell.blogspot.nl/2011/03/hoogle-for-your-language-ie-f-scala-ml.html}
		\item Contact me!
	\end{itemize}
\end{frame}

\subsection{Numbers}
\begin{frame}{Numbers\setcounter{footnote}{0}\footnotemark}
	\setcounter{footnote}{1}
	\begin{columns}[t]
		\begin{column}{.5\textwidth}
			\begin{itemize}
				\item Database

					\begin{description}[Syntax constructs]
						\small
						\item[Modules] 750
						\item[Functions] 15,297
						\item[Unique types] 13,571
						\item[Type tree depth] 8
						\item[Type definitions] 2,195
						\item[Classes] 262
						\item[Instances] 1958
						\item[Derivations] 1,182
						\item[Syntax constructs] 35
					\end{description}
			\end{itemize}
		\end{column}
		\begin{column}{.5\textwidth}
			\begin{itemize}
				\item Lines of code\footnotemark
					% cloc --exclude-dir=clean-compiler,CleanRep.2.2_files,CleanRep.2.2.css,storage,cache,Clean\ System\ Files,types.json,typetree.dot,cloogle.log,tags .

					\begin{description}[Bourne Shell]
						\small
						\item[Clean] 4,739
						\item[JavaScript] 1,657
						\item[PHP] 831
						\item[HTML] 569
						\item[CSS] 406
						\item[Python] 110
						\item[Bourne Shell] 71
					\end{description}
			\end{itemize}
		\end{column}
	\end{columns}

	\medskip
	\begin{itemize}
		\item Visitor statistics: \https{cloogle.org/stats/longterm.html}
	\end{itemize}

	\setcounter{footnote}{1}
	\footnotetext{2017-10-28}
	\setcounter{footnote}{2}
	\footnotetext{On the web frontend and submodules, excluding the Clean compiler}
\end{frame}

\subsection{Links}
\begin{frame}[shrink]{Links}
	\footnotesize
	\textbf{Core system:}
	\begin{description}[VS Code plugin]
		\item[API] \https{github.com/clean-cloogle/libcloogle}
		\item[Core] \https{github.com/clean-cloogle/Cloogle}
		\item[Web] \https{github.com/clean-cloogle/cloogle.org}
		\item[JS highlighter] \https{github.com/clean-cloogle/clean.js}
		\item[Pygments lexer] \https{github.com/clean-cloogle/pygments-lexer-clean}
		\item[Pretty printer] \https{github.com/clean-cloogle/CleanPrettyPrint}
		\item[Type unifier] \https{github.com/clean-cloogle/CleanTypeUnifier}
	\end{description}

	\textbf{Clients:}
	\begin{description}[VS Code plugin]
		\item[vim-clean] \https{github.com/camilstaps/vim-clean}
		\item[CLI app] \https{github.com/clean-cloogle/cloogle-cli}
		\item[Telegram bot] \https{telegram.me/CloogleBot}; \https{github.com/clean-cloogle/CloogleBot}
		\item[IRC bot] \#cloogle on \https{freenode.net}; \https{github.com/clean-cloogle/clean-irc}
		\item[Email client] \mailto{query@cloogle.org}; \https{github.com/clean-cloogle/cloogle-mail}
		\item[VS Code plugin] \https{github.com/W95Psp/CleanForVSCode}
	\end{description}

	\textbf{Miscellaneous:}
	\begin{description}[Pygments lexer]
		\item[cloogle-tags] \https{github.com/clean-cloogle/cloogle-tags}
		\item[These slides] \https{github.com/clean-cloogle/presentation-NL-FP-2018}
	\end{description}
\end{frame}

\setcounter{framenumber}{\value{finalframe}}

\end{document}