%% algorithmlite.tex -- documentation for the algorithmlite package
%%
%% Copyright (c) 2026 Munehiro Yamamoto <munepixyz@gmail.com>
%% License: LPPL 1.3c or later
%%
%% Build: pdflatex algorithmlite.tex (twice)
\documentclass{article}
\usepackage[margin=28mm]{geometry}
\usepackage{xcolor}
\usepackage{array}
\usepackage{algorithmlite}
\usepackage{algorithmic}
\usepackage[colorlinks, allcolors=blue!50!black]{hyperref}
\setlength\emergencystretch{2em}
\newcommand*\alversion{v1.0 (2026/10/26)}
\newcommand*\cs[1]{\texttt{\char`\\#1}}
\newcommand*\pkg[1]{\textsf{#1}}
\newcommand*\env[1]{\texttt{#1}}
\newcommand*\meta[1]{$\langle$\textit{#1}$\rangle$}

\title{The \pkg{algorithmlite} package\\
  \large A lightweight algorithm float without the float package}
\author{Munehiro Yamamoto\\
  \url{https://github.com/munepi/algorithmlite}}
\date{\alversion}

\begin{document}
\maketitle

\section{Introduction}

The \pkg{algorithm} package defines the \env{algorithm} float with
\cs{newfloat} of the \pkg{float} package.  The \pkg{float} package
redefines \cs{caption} as a whole, for every float of the document,
and it is often in the way of the class and of other packages that
format captions.

The \pkg{algorithmlite} package defines the environments
\env{algorithm} and \env{algorithm*} in the same way as the standard
classes define \env{figure} and \env{table}: with \cs{@float} and
\cs{@dblfloat} of the \LaTeX{} kernel, so that the captions of
algorithms are set by the \cs{@makecaption} of the class, as those of
figures and tables.  The \pkg{float} package is not loaded.  If no
other package gives the placement \texttt{[H]}, \pkg{algorithmlite}
gives a minimal one.

The content of an algorithm is not the business of this package: load
\pkg{algorithmic}, \pkg{algpseudocode} (\pkg{algorithmicx}) or any
other package for it.

\begin{algorithm}[H]
\caption{Euclid's algorithm}\label{alg:euclid}
\begin{algorithmic}[1]
\REQUIRE $a \geq 0$, $b \geq 0$
\WHILE{$b \neq 0$}
  \STATE $(a, b) \leftarrow (b, a \bmod b)$
\ENDWHILE
\RETURN $a$
\end{algorithmic}
\end{algorithm}

\paragraph{Supported formats/engines}
pdf\LaTeX, Xe\LaTeX, Lua\LaTeX{} (with or without Lua\TeX-ja),
p\LaTeX{} and up\LaTeX{} (with dvipdfmx).  \LaTeX2e{} 2020-10-01 or
later is required.

\section{Usage}

\begin{verbatim}
\usepackage{algorithmlite}
\usepackage{algorithmic}   % or algpseudocode, ...

\begin{algorithm}[tbp]     % or [H]
\caption{Euclid's algorithm}\label{alg:euclid}
\begin{algorithmic}[1]
  ...
\end{algorithmic}
\end{algorithm}

\listofalgorithms
\end{verbatim}

\noindent
Algorithm~\ref{alg:euclid} above is set with \texttt{[H]}.  The package
has no options.

\section{What is defined}

\begin{description}
\item[\env{algorithm}, \env{algorithm*}] The float and its two-column
  variant, as \env{figure} and \env{figure*}.  The default placement
  (\cs{fps@algorithm}) is \texttt{tbp}.

\item[The counter \texttt{algorithm}] With \cs{chapter}, it is reset
  at every chapter, and \cs{thealgorithm} is the chapter number, a
  period and \meta{n} (just \meta{n} before the first chapter), as
  \cs{thefigure} of the book classes; otherwise it is \meta{n}.  Redefine \cs{thealgorithm} for another numbering.

\item[\cs{algorithmname}] \texttt{Algorithm}; in Japanese (the word
  ``algorithm'' in katakana) with p\TeX, up\TeX{} and Lua\TeX-ja, unless the class
  option \texttt{english} of jsclasses or the Lua\TeX-ja classes is
  given.  Lua\TeX-ja may also be loaded after \pkg{algorithmlite}.

\item[\cs{listalgorithmname}] \texttt{List of Algorithms}; in
  Japanese, ``algorithm'' followed by the word for ``list'' (as
  ``List of Figures'' is in jsclasses).

\item[\cs{fnum@algorithm}] \cs{algorithmname}\meta{sep}%
  \cs{thealgorithm}, where \meta{sep} is taken from \cs{fnum@figure}
  of the class if it is \cs{figurename}\meta{sep}\cs{thefigure}:
  \cs{nobreakspace} in the standard classes, \cs{nobreak} in jsclasses
  and the Lua\TeX-ja classes, \verb|~| in the p\LaTeX{} standard
  classes, nothing in jlreq.  Otherwise \meta{sep} is \cs{nobreak} for
  the Japanese name and \cs{nobreakspace} for the English one.

\item[\cs{listofalgorithms}] The list of algorithms, from the file
  \texttt{.loa}.  It is \cs{listoffigures} of the class with
  \cs{listalgorithmname} and \texttt{.loa}, so that it looks like the
  list of figures (a \cs{chapter*} or a \cs{section*}, the running
  heads, \dots).  The entries are set with \cs{l@algorithm}, which is
  \cs{l@figure} of the class.

\item[The float type] The float type \cs{ftype@algorithm} is a bit,
  as are \cs{ftype@figure}${}=1$ and \cs{ftype@table}${}=2$.  It is
  the next free bit, $4$ in most documents.  The counter of the
  \pkg{float} package (also used by \pkg{floatrow} and \pkg{newfloat})
  and that of memoir are shared: if one of them is already there, its
  value is taken and the counter is moved on; if the \pkg{float} or
  \pkg{floatrow} package is loaded later (e.g.\ by \pkg{minted}), its
  counter is moved past $4$.  The \pkg{newfloat} package alone starts
  at $8$.
\end{description}

\section{The placement \texttt{[H]}}

At \verb|\begin{document}|, if neither the \pkg{float} package nor the
\pkg{floatrow} package is loaded and \cs{@float@HH} is not defined,
\pkg{algorithmlite} defines the placement \texttt{[H]}: the float is
put in a box ``here'', in the text, with \cs{intextsep} above and
below it, and \cs{caption} works in it as in a float.  As with the
\pkg{float} package, \texttt{[H]} is then available for every float
type: \env{figure}, \env{table}, \env{algorithm}, \dots

If the \pkg{float} package is loaded (before or after
\pkg{algorithmlite}), its \texttt{[H]} is used.

\section{Errors}

\begin{description}
\item[\texttt{Package `algorithm' cannot be used with algorithmlite}]
  The \pkg{algorithm} or \pkg{algorithm2e} package is loaded before or
  after \pkg{algorithmlite}.  Both define the \env{algorithm}
  environment; load only one of them.
\item[\texttt{The algorithm environment or counter is already
  defined}] \pkg{algorithmlite} does not redefine them.
\end{description}

\section{Limitations}

\begin{itemize}
\item \texttt{algorithm*[H]} in two-column mode is not supported (as
  with the \pkg{float} package).  In one-column mode it works.
\item Vertical writing (tate) is outside the scope of this version.
\end{itemize}

\section{Tests}

\verb|make test| compiles every test twice with pdf\LaTeX, Xe\LaTeX,
Lua\LaTeX, p\LaTeX{} and up\LaTeX{} (+ dvipdfmx) and checks the log.
\texttt{test-common.tex} checks the numbers, names, float types and
\cs{ref} immediately, and the pages of \texttt{[H]} and \texttt{[p]}
floats from records written to the \texttt{.aux} file at shipout
(\texttt{ALGL-RESULT OK}).

\begin{center}
\begin{tabular}{l>{\raggedright\arraybackslash}p{.62\linewidth}}
  \hline
  Test & What it covers\\
  \hline
  \texttt{test-basic.tex}     & numbering with and without chapters,
                                names (English/Japanese), \cs{fnum@algorithm},
                                \texttt{[H]}, \texttt{[p]}, \env{figure}\texttt{[H]},
                                \env{algorithm*}, \cs{ref},
                                \cs{listofalgorithms}; article, book,
                                jsclasses, Lua\TeX-ja classes, jlreq,
                                p\LaTeX{} standard classes\\
  \texttt{test-hyperref.tex}  & \texttt{test-basic.tex} with
                                \pkg{hyperref}: no duplicate destinations\\
  \texttt{test-twocolumn.tex} & \env{algorithm*} and \texttt{[H]} in
                                two-column mode\\
  \texttt{test-compat.tex}    & \pkg{float} before/after, \pkg{newfloat},
                                \pkg{caption}, memoir\\
  \texttt{test-errors.tex}    & the error messages\\
  \hline
\end{tabular}
\end{center}

\section{History}

\begin{description}
\item[v1.0 (2026/10/26)] First public release.
\end{description}

\section{License}

This package is licensed under the conditions of the \LaTeX{} Project
Public License, either version~1.3c of this license or any later
version.

\medskip
\noindent
Copyright \copyright{} 2026 Munehiro Yamamoto

\end{document}