% \iffalse meta-comment
% ======================================================================
% floatrowbytocbasic.dtx
% Copyright © 2008–2023 Markus Kohm
%
% This work is a KOMA-Script spin-off.  For the original sources of
% KOMA-Script's `floatrow.hak' see file `scrhack.dtx' in the KOMA-Script
% sources at <https://sourceforge.net/p/koma-script/code/>.
%
% Development is taking place as part of `third-party-hacks' at
% <https://github.com/komascript/third-party-hacks>.  New issues should
% be reported there as well as known issues can be found.
%
% This work may be distributed and/or modified under the conditions of
% the LaTeX Project Public License, version 1.3c of the license.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.<3c or later is part of all distributions of LaTeX
% version 2005/12/01 or later and of this work.
%
% The Current Maintainer and author of this work is Markus Kohm.
%
% This work consists of the file `floatrowbytocbasic.dtx' and
% `README.md'.
%
% The recommended way to install `floatrowbytocbasic' is to use
% the package manager of your TeX distribution.
% ======================================================================
%
%<*dtx>
\ifx\ProvidesFile\undefined\def\ProvidesFile#1[#2]{}\fi
\ProvidesFile{floatrowbytocbasic.dtx}
%</dtx>
%<*dtx|package>
%<package>\ProvidesPackage{floatrowbytocbasic}
             [2023-08-16 v1.0
%<dtx>              sources and unpack driver of
              improved floatrow package using tocbasic]
%</dtx|package>
%<*dtx>
\ifx\documentclass\undefined
  \input docstrip.tex
  \generate{%
    \file{floatrowbytocbasic.sty}{%
      \from{floatrowbytocbasic.dtx}{package}%
    }%
  }%
\else
  \let\endbatchfile\relax
\fi
\endbatchfile
\documentclass[ngerman,USenglish]{koma-script-source-doc}
\usepackage{babel}
\usepackage{csquotes}
\usepackage[style=alphabetic]{biblatex}
\begin{filecontents}[force]{\jobname.bib}
@online{pkg:floatrow,
  author={Olga Lapko},
  title={\pkg*{floatrow} --- Modifying the layout of floats},
  version={0.3b},
  date={2008-08-02},
  url={https://ctan.org/pkg/floatrow},
  urldate={2023-07-18},
  note={The \pkg*{floatrow} package provides many ways to customize layouts of
        floating environments and has code to cooperate with the \pkg{caption}
        3.x package. The package offers mechanisms to put floats side by side,
        and to put the caption beside its float. The \pkg*{floatrow} settings
        could be expanded to the floats created by packages \pkg{rotating},
        \pkg{wrapfig}, \pkg{subfig} (in the case of rows of subfloats), and
        \pkg{longtable}.},
}
@manual{pkg:floatrow:manual,
  author={Olga Lapko},
  date={2009-08-02},
  title={The \pkg*{floatrow} package},
  url={http://mirrors.ctan.org/macros/latex/contrib/floatrow/floatrow.pdf},
  urldate={2023-07-18},
  abstract={This package was created as extension of the \pkg{float} package.
            The \pkg*{floatrow} package borrows core code from the \pkg{float}
            and \pkg{rotfloat} packages, so you must not load these packages.},
}
@online{pkg:xpatch,
  author   = {Enrico Gregorio},
  version  = {0.3},
  date     = {2020-03-25},
  title    = {\pkg*{xpatch} – Extending \pkg{etoolbox} patching commands},
  url      = {https://ctan.org/pkg/xpatch},
  urldate  = {2023-07-19},
  note     = {The package generalises the macro patching commands provided
              by Philipp Lehmann's \pkg{etoolbox}.},
}
@manual{pkg:xpatch:manual,
  author   = {Enrico Gregorio},
  version  = {0.3},
  date     = {2020-03-25},
  title    = {The \pkg*{xpatch} package
              extending \pkg{etoolbox} patching commands},
  url      = {http://mirrors.ctan.org/macros/latex/contrib/xpatch/xpatch.pdf},
  urldate  = {2023-07-19},
  abstract = {},
}
@online{pkg:scrlfile,
  author   = {Markus Kohm},
  version  = {3.41},
  date     = {2023-07-07},
  title    = {\pkg*{scrlfile} – Installation control (not only) for
              \KOMAScript{} packages},
  url      = {https://ctan.org/pkg/scrlfile},
  urldate  = {2023-07-19},
  note     = {The package provides hooks for the execution of commands before
              or after loading files, classes or packages independent from the
              \LaTeX{} kernel version.},
}
@online{pkg:koma-script,
  author={Markus Kohm},
  version={3.41},
  date={2023-07-07},
  title={{\KOMAScript} --- A bundle of versatile classes and packages},
  url={https://ctan.org/pkg/koma-script},
  urldate={2023-07-14},
  note={The \KOMAScript{} bundle provides replacements for the \pkg*{article},
        \pkg*{report}, and \pkg*{book} classes with emphasis on typography and
        versatility. There is also a letter class.},
}
@online{pkg:tocbasic,
  author={Markus Kohm},
  version={3.41},
  date={2023-07-07},
  title={\pkg*{tocbasic} --- Management of tables/lists of contents (and the
         like)},
  url={https://ctan.org/pkg/tocbasic},
  urldate={2023-07-14},
  note={The package provides means to create specialised ``table of
        contents''-like lists of features of a document.},
}
@manual{pkg:koma-script:manual:de,
  author={Markus Kohm},
  date={2023-06-16},
  title={{\KOMAScript}},
  subtitle={Die Anleitung},
  url={http://mirrors.ctan.org/macros/latex/contrib/koma-script/scrguide-de.pdf},
  urldate={2023-07-04},
}
@manual{pkg:koma-script:manual:en,
  author={Markus Kohm},
  date={2023-06-16},
  title={{\KOMAScript}},
  subtitle={The Guide},
  url={http://mirrors.ctan.org/macros/latex/contrib/koma-script/scrguide-en.pdf},
  urldate={2023-07-14},
}
\end{filecontents}
\addbibresource{\jobname.bib}
\setcounter{StandardModuleDepth}{2}
\begin{document}
  \nocite{pkg:floatrow,pkg:koma-script,pkg:tocbasic}
  \DocInput{floatrowbytocbasic.dtx}
\end{document}
%</dtx>
%\fi
%
% \changes{v0.1}{2023/06/01}{start of \KOMAScript{} spin-off}
% \changes{v1.0}{2023/08/19}{first package release}
%
% \GetFileInfo{floatrowbytocbasic.dtx}
% \title{Improving Package \pkg{floatrow} Using
%  \href{https://komascript.de/}{\KOMAScript} Package \pkg{tocbasic}}
% \author{\href{mailto:komascript@gmx.info}{Markus Kohm}}
% \date{Version \filedate{} \fileversion}
% \maketitle
% \begin{abstract}
%   Package \pkg*{floatrowbytocbasic} has started as hack module of the
%   \KOMAScript{} package \pkg*{scrhack} years ago to fix an issue when using
%   package \pkg{floatrow} with \KOMAScript~3.  This became necessary because
%   package \pkg{floatrow} still depends on an interface once proposed by the
%   \KOMAScript{} author, but which has long since failed to meet
%   requirements. Unfortunately, this problem could not be solved in dialog
%   with the author of \pkg{floatrow}. Although \pkg*{floatrowbytocbasic} still
%   loads the \pkg{floatrow} package, it then changes some internal commands to
%   use and optimally support the \KOMAScript{} package \pkg{tocbasic}. On the
%   one hand, the user interface of \pkg{floatrow} remains usable unchanged,
%   but at the same time the package benefits from many possibilities of
%   \pkg{tocbasic}.
% \end{abstract}
%
% \tableofcontents
%
%\iffalse
%<*doc>
%\fi
\section{Why should I use this package instead of
  \texorpdfstring{\pkg{floatrow}}{floatrow} only if I use a \KOMAScript{}
  class or \KOMAScript{} package \texorpdfstring{\pkg{tocbasic}}{tocbasic}?}
\label{sec:whywithkomascript}

The main symptom of using a deprecated interface to \KOMAScript{} by package
\pkg{floatrow}, namely the use of \cs{float@listhead} and
\cs{float@addtolists}, are corresponding warnings when using one of the
\KOMAScript{} classes at the same time, for example:
\begin{verbatim}
  Class scrbook Warning: \float@addtolists detected!
  (scrbook)              Implementation of \float@addtolist became
  (scrbook)              deprecated in KOMA-Script v3.01 2008/11/14 and
  (scrbook)              has been replaced by several more flexible
  (scrbook)              features of package `tocbasic`.
  (scrbook)              Since Version 3.12 support for deprecated
  (scrbook)              \float@addtolist interface has been
  (scrbook)              restricted to only some of the KOMA-Script
  (scrbook)              features and been removed from others.
  (scrbook)              Loading of package `scrhack' may help to
  (scrbook)              avoid this warning, if you are using a
  (scrbook)              a package that still implements the
  (scrbook)              deprecated \float@addtolist interface.
\end{verbatim}
or
\begin{verbatim}
  Class scrbook Warning: \float@listhead detected!
  (scrbook)              Implementation of \float@listhead became
  (scrbook)              deprecated in KOMA-Script v3.01 2008/11/14 and
  (scrbook)              has been replaced by several more flexible
  (scrbook)              features of package `tocbasic`.
  (scrbook)              Maybe implementation of \float@listhead will
  (scrbook)              removed from KOMA-Script soon.
  (scrbook)              Loading of package `scrhack' may help to
  (scrbook)              avoid this warning, if you are using a
  (scrbook)              a package that still implements the
  (scrbook)              deprecated \float@listhead interface.
\end{verbatim}

If you know, that the issue is because of loading package \pkg{floatrow} you
can avoid it using \pkg{floatrowbytocbasic} as explained in
\autoref{sec:howtouse}.

\section{Why should I use this package instead of
  \texorpdfstring{\pkg{floatrow}}{floatrow} only if I don't use a
  \KOMAScript{} class or package?}
\label{sec:whywithoutkomascript}

Package \pkg{floatrow} does not check if a file extension or environment
already has been defined when using \cs{DeclareNewFloatType}. So several
definitions of float environments either with the same name or the same file
extension could happen by accident. Package \pkg*{floatrowbytocbasic} adds
test to avoid such issues. But it also allows to redefine an environment or
reuse a file extension, if you want. Alternatively you can force the
definition or do the definition only if needed. See description of
\cs{DeclareFloatType}, \cs{RedeclareFloatType} and \cs{ProvideFloatType} in
\autoref{sec:howtouse} for more information.

Package \pkg{tocbasic} provides several additional features, e.g.:
\begin{itemize}
\item automatic handling of language switching using \pkg{babel},
\item optional numbered heading for a list/table of contents,
\item optional adding an entry to the table of contents for a list/table of
  contents even if the heading is not numbered,
\item easy configuration of entries to a list/table of contents.
\end{itemize}
Several more features can be added by the class or other packages. See section
about \pkg*{tocbasic} in the \KOMAScript{} manual, either
\autocite{pkg:koma-script:manual:en} or \autocite{pkg:koma-script:manual:de}.

\section{How to use
  \texorpdfstring{\pkg*{floatrowbytocbasic}}{floatrowbytocbasic}}
\label{sec:howtouse}

In the document preamble of your document you just can replace
\begin{verbatim}
  \usepackage{floatrow}
\end{verbatim}
by
\begin{verbatim}
  \usepackage{floatrowbytocbasic}
\end{verbatim}
to load package \pkg*{floatrowbytocbasic}. This does still also load package
\pkg{floatrow} but additionally patches several commands of \pkg{floatrow} to
avoid the issues shown in \autoref{sec:whywithkomascript}.

If you want you can alternatively also load both packages explicitly, either
\pkg{floatrow} before \pkg{floatrowbytocbasic} or---if you
want---\pkg{floatrowbytocbasic} before \pkg{floatrow}. This is also useful, if
you use a package, that uses \pkg{floatrow} itself. In this case, you always
should load \pkg{floatrowbytocbasic} \emph{before} the package, that uses
\pkg{floatrow}. Otherwise it is very likely that for some new float
environments the enhancements of \pkg*{floatrowbytocbasic} will not be
used. Only if \pkg*{floatrowbytocbasic} is loaded before the first use of
\cs{DeclareNewFloatType} can it be ensured that the definition of the new
sliding environments is really done with the help of \pkg{tocbasic} and thus
its extended user interface is used.

When using a class that uses \pkg{floatrow}, the correct operation can be
ensured with
\begin{verbatim}
  \AddToHook{package/floatrow/after}{\RequirePackage{floatrowbytocbasic}}
\end{verbatim}
even before \cs{documentclass}. This requires at least \LaTeX{}
2020/10/01. For older versions of \LaTeX{} you can use
\begin{verbatim}
  \RequirePackage{scrlfile}
  \AfterPackage{floatrow}{\RequirePackage{floatrowbytocbasic}}
\end{verbatim}
also before \cs{documentclass}. This would require the \KOMAScript{} package
\pkg{scrlfile}\nocite{pkg:scrlfile}.

The user interface of \pkg*{floatrowbytocbasic} is the same as of
\pkg{floatrow}, see \autocite{pkg:floatrow:manual}. Following we document only
the differences.

\DescribeCommand{\DeclareNewFloatType}
\DescribeCommand{\ProvideFloatType}
\DescribeCommand{\RedeclareFloatType}
\DescribeCommand{\DeclareFloatType}
See \autocite[section~2]{pkg:floatrow:manual} for the basic usage of
\cs{DeclareNewFloatType}. The command takes two mandatory arguments. It is of
the form:
\begin{quote}
  \cs{DeclareNewFloatType}\marg{type}\marg{options}
\end{quote}
\pkg{floatrowbytocbasic} adds the registration of the file extension of the
new \meta{type} given either by option \opt{fileext} in the \meta{options} or
implicitly (see \autocite[section~4]{pkg:floatrow:manual}). The main problem
here is to decide what to do, if \meta{ext} already has been
registered. Package \pkg{floatrow} simply does not care for this case. It does
neither report an error nor a warning, but just redefine the float \meta{type}
and reuses the auxiliary file extension. Because of the ``\texttt{New}'' in
the name of the command, we have decided to report an error instead, but only
of the owner/category differs and therefore is not \texttt{float}. But we
also decided to define three new commands:
\begin{quote}\raggedright
  \cs{DeclareFloatType}\marg{type}\marg{options}\\
  \cs{ProvideFloatType}\marg{type}\marg{options}\\
  \cs{RedeclareFloatType}\marg{type}\marg{options}
\end{quote}
\cs{DeclareFloatTpye} also does not care for already existing \meta{type}
environment or already registered file extension. \cs{DeclareNewFloatType}
reports and error for an already existing \meta{type}
environment. \cs{ProvideFloatType} does not overwrite existing \meta{type}
environment or already registered file extensions for other
owners. \cs{RedeclareFloatType} does overwrite only already existing
\meta{type} environment with registered file extension. There are also cases
like defined \cs{\meta{type}} but not \cs{end\meta{type}} or not defined
environment \meta{type} but registered file extension. But there are no
special commands to handle these. If users need to take care for these cases,
they can test for definition using the \LaTeX{} kernel macro \cs{@ifundefined}
and the \pkg{tocbasic} command \cs{Ifattoclist}, described in the
\KOMAScript{} user manuals \autocite{pkg:koma-script:manual:en}
resp. \autocite{pkg:koma-script:manual:de}.
%
% \iffalse
%</doc>
% \fi
%
% \MaybeStop{\printbibliography[heading=bibintoc]\PrintIndex}
%
% \iffalse
%<*package>
%<@@=floatrowbytocbasic>
% \fi
% \section{Implementation}
%
% \pkg{floatrowbytocbasic} depend on \KOMAScript{} package \pkg{tocbasic}. So
% we load it already before everything else. We use this package also to
% require at least \KOMAScript{} 3.41, which is one version before the
% intended spin-off.
%    \begin{macrocode}
\RequirePackage{tocbasic}[2023/07/07]
%    \end{macrocode}
%
% We also load package \pkg{floatrow}, because we reuse most of the code:
%    \begin{macrocode}
\RequirePackage{floatrow}
%    \end{macrocode}
%
% As often as possible, we do not redefine macors of \pkg{floatrow}, but patch
% them using \pkg{xpatch}\nocite{pkg:xpatch}:
%    \begin{macrocode}
\RequirePackage{xpatch}
%    \end{macrocode}
%
% We also use some \LaTeX3 functions. So if the \LaTeX{} kernel is
% too old, we require \pkg{expl3}:
%    \begin{macrocode}
\@ifundefined{ExplSyntaxOn}{%
  \RequirePackage{expl3}%
}{}
%    \end{macrocode}
%
% \begin{command}{\DeclareFloatType}
% Basicly \cs{DeclareFloatType} is \cs{DeclareNewFloatType} of
% \pkg{floatrow}:
%    \begin{macrocode}
\@ifundefined{NewCommandCopy}{\let\DeclareFloatType\DeclareNewFloatType}{%
  \NewCommandCopy\DeclareFloatType\DeclareNewFloatType
}
%    \end{macrocode}
% But we also have to take care, that a not yet registered file extension has
% to be registered.
% \begin{description}
% \item[Note:] We do not need to setup feature \texttt{chapteratlist}, because
%   classes like the \KOMAScript{} classes should use
%\begin{verbatim}
%  \AtAddToTocList[float]{\setuptoc{\@currext}{chapteratlist}}
%\end{verbatim}
%   to implement such features.
% \end{description}
%    \begin{macrocode}
\newcommand*{\floatrowbytocbasic@incompatibility@error}[1]{%
  \PackageError{floatrowbytocbasic}{incompatible definition of
    \expandafter\string\csname #1\endcsname}{%
    Package `floatrowbytocbasic' depends on the original definition of
    package\MessageBreal
    `floatrow'.\MessageBreak
    Some changes to that definition are tolerated.\MessageBreak
    \@ifundefined{#1}%
    {But it seems the definition is completely missing!}%
    {But the current definition is incompatible!}%
    \MessageBreak
    Make sure, you have installed the original package `floatrow' as
    referred\MessageBreak
    by section ``References'' of the manual.%
  }%
}  
\xpatchcmd{\DeclareFloatType}{%
  \xdef\@tempa{\noexpand\flrow@types{\the\flrow@types \FR@tmp{#1}}}%
  \@tempa
}{%
  \Ifattoclist{\@nameuse{ext@\FB@captype}}{%
    \let\reserved@a\relax
    \owneroftoc[\def\reserved@a]{\@nameuse{ext@\FB@captype}}\relax
    \@ifundefined{reserved@a}{}{%
      \Ifstr{\reserved@a}{float}{%
        \PackageInfo{floarowtbytocbasic}{%
          reusing file extension `\@nameuse{ext@\FB@captype}' for\MessageBreak
          float type `#1'%
        }%
      }{%
        \PackageWarning{floatrowbytocbasic}{%
          reusing file extension `\@nameuse{ext@\FB@captype}' of owner\MessageBreak
          `\reserved@a' for float `#1'\MessageBreak
          not recommended%
        }%
      }%
    }%
  }{%
    \addtotoclist[float]{\@nameuse{ext@\FB@captype}}%
  }%
  \xdef\@tempa{\noexpand\flrow@types{\the\flrow@types \FR@tmp{#1}}}%
  \@tempa
}{}{%
  \floatrowbytocbasic@incompatibility@error{DeclareNewFloatType}%
}
%    \end{macrocode}
% \begin{description}
% \item[Note:] In difference to \pkg{floatrow} we think, reusing a counter is
%   not a big problem, so we don't report an error.
% \end{description}
%    \begin{macrocode}
\xpatchcmd{\DeclareFloatType}{%
  \newcounter{#1}%
}{%
  \@ifundefined{c@#1}{\newcounter{#1}}{%
    \PackageInfo{floatrowbytocbasic}{%
      reusing existing counter for float type `#1'%
    }%
  }%
}{}{%
  \floatrowbytocbasic@incompatibility@error{DeclareNewFloatType}%
}  
\xpatchcmd{\DeclareFloatType}{%
  \@namedef{l@#1}{\@dottedtocline{1}{1.5em}{2.3em}}%
}{%
  \@ifundefined{l@#1}{\expandafter\let\csname l@#1\endcsname\l@figure
    \@ifundefined{l@#1}{%
      \DeclareTOCStyleEntry[level=1,numwith=2.3em,indent=1.5em]{default}{#1}%
    }{}%
  }{}%
}{}{%
  \floatrowbytocbasic@incompatibility@error{DeclareNewFloatType}%
}
%    \end{macrocode}
% \end{command}
%
% \begin{command}{\DeclareNewFloatType,\ProvideFloatType,\RedeclareFloatType}
% \cs{DeclareNewFloatType} and \cs{RedeclareFloatType} similar to
% \cs{newcommand} and \cs{renewcommand} do some tests and maybe report an
% error, before (nevertheless) defining the float.
% \begin{description}
% \item[Note:] The test for already defined floats is somehow complicated,
%   because \pkg{floatrow} delays the definition until
%   |\begin{document}|. Before, there is only a list of \cs{FR@tmp} commands
%   stored in toks register \cs{flrow@types}. But we also have to test for
%   reusing another environment instead of a float.
% \end{description}
%    \begin{macrocode}
\renewcommand{\DeclareNewFloatType}[2]{%
  \floatrowbytocbasic@get@currext{#1}{#2}%
  \@tempswatrue
  \begingroup
    \def\FR@tmp##1{%
      \Ifstr{#1}{##1}{\aftergroup\@tempswafalse}{}%
    }%
    \the\flrow@types
  \endgroup
  \if@tempswa
    \expandafter\@ifdefinable\csname #1\endcsname {%
      \Ifattoclist{\floatrowbytocbasic@currext}{%
        \let\reserved@a\relax
        \owneroftoc[\def\reserved@a]{\floatrowbytocbasic@currext}\relax
        \@ifundefined{reserved@a}{%
          \DeclareFloatType{#1}{#2}%
        }{%
          \Ifstr{\reserved@a}{float}{%
            \PackageInfo{floatrowbytocbasic}{%
              reusing `\floatrowbytocbasic@currext' of owner `float'%
            }%
            \DeclareFloatType{#1}{#2}%
          }{%
            \PackageError{floatrowbytocbasic}{%
              reusing `\floatrowbytocbasic@currext' of owner `\reserved@a' not
              allowed%
            }{%
              Each file extension should be used only once.\MessageBreak
              Reusing is only allowed with the same owner/category.\MessageBreak
              You, the class, or another package already uses
              `\floatrowbytocbasic@currext'.\MessageBreak
              \@eha
            }%
          }%
        }%
      }{%
        \DeclareFloatType{#1}{#2}%
      }%
    }%
  \else
    \PackageError{floatrowbytocbasic}{Float `#1' already defined}{%
      Each float can be defined only once using
      \string\DeclareNewFloatType.\MessageBreak
      If you want to redefine an already existing float, please
      use\MessageBreak
      \string\RedeclareFloatType.\MessageBreak
      \@eha
    }%
  \fi
}
\newcommand{\ProvideFloatType}[2]{%
  \@ifundefined{#1}{%
    \@tempswatrue
    \begingroup
      \def\FR@tmp##1{%
        \Ifstr{#1}{##1}{\aftergroup\@tempswafalse}{}%
      }%
      \the\flrow@types
    \endgroup
    \if@tempswa    
      \DeclareNewFloatType{#1}{#2}%
    \fi
  }{}% 
}
\newcommand{\RedeclareFloatType}[2]{%
  \@tempswafalse
  \@ifundefined{#1}{%
    \begingroup
      \def\FR@tmp##1{%
        \Ifstr{#1}{##1}{\aftergroup\@tempswatrue}{}%
      }%
      \the\flrow@types
    \endgroup
  }{\@tempswatrue}%  
  \floatrowbytocbasic@get@currext{#1}{#2}%
  \if@tempswa
    \Ifattoclist{\floatrowbytocbasic@currext}{%
      \removefromtoclist{\floatrowbytocbasic@currext}%
    }{%
      \PackageError{floatrowbytocbasic}{%
        extension `\floatrowbytocbasic@currext' not yet registered%
      }{%
        I can only renew floats with already registered
        extensions.\MessageBreak
        \@ehc
      }%
    }%
  \else
    \@latex@error{Environment #1 undefined}\@ehc
    \removefromtoclist{\floatrowbytocbasic@currext}%
  \fi
  \DeclareFloatType{#1}{#2}%
}
%    \end{macrocode}
% \end{command}
%
% \ExplSyntaxOn
% \begin{macro}{\__floatrowbytocbasic_get_ext_from_prop:nn,
%               \floatrowbytocbasic@get@currext}
% \ExplSyntaxOff
% Helper macros to set \cs{floatrowbytocbasic@currext} to the extension set by
% the options (=\#2). \#1 is the name of the new float type. We are not really
% interested in handling of all the options. So we just use the options to
% setup a property list and then get the one interesting property.
%    \begin{macrocode}
\ExplSyntaxOn
\prop_new:N \@@_DeclareNewFloatType_prop
\tl_new:N \@@_ext_tl
\cs_new:Nn \@@_get_ext_from_prop:nn
  {
    \prop_set_from_keyval:Nn \@@_DeclareNewFloatType_prop { #2 }
    \prop_get:NnN \@@_DeclareNewFloatType_prop { fileext } \@@_ext_tl
    \quark_if_no_value:NT \@@_ext_tl
      {
        \tl_set:Nn \@@_ext_tl { lo#1 }
      }
  }
\newcommand*{\floatrowbytocbasic@get@currext}[2]{%
  \@@_get_ext_from_prop:nn { #1 } { #2 }
  \let\floatrowbytocbasic@currext\@@_ext_tl
}
\ExplSyntaxOff 
%    \end{macrocode}
% \end{macro}
% \ExplSyntaxOff
%
% \begin{command}{\listof}
% This command is redefined using a complete new definition using
% \pkg{tocbasic}'s \cs{listoftoc}.
%    \begin{macrocode}
\renewcommand*{\listof}[2]{%
  \@ifundefined{ext@#1}{\flrow@error{Unknown float style `#1'}}{%
    \@ifundefined{l@#1}{\expandafter\let\csname l@#1\endcsname\l@figure
      \@ifundefined{l@#1}{%
        \DeclareTOCStyleEntry[level=1,numwidth=2.3em,indent=1.5em]
        {default}{#1}%
      }{}%
    }{}%
    \listoftoc[{#2}]{\csname ext@#1\endcsname}%
  }%
}%
%    \end{macrocode}
% \end{command}
%
% \iffalse
%</package>
% \fi
%
% \Finale
% \PrintChanges
%  
% \endinput
% Local Variables:
% mode: doctex
% ispell-local-dictionary: "en_US"
% eval: (flyspell-mode 1)
% TeX-master: t
% End: