% \iffalse meta-comment
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% fillwith.dtx
% Additions and changes Copyright (C) 2024 Clea F. Rees.
% Code from skeleton.dtx Copyright (C) 2015-2024 Scott Pakin (see below).
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3c
% of this license or (at your option) any later version.
% The latest version of this license is in
%   https://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions of LaTeX
% version 2008-05-04 or later.
%
% This work has the LPPL maintenance status \muaintained'.
%
% The Current Maintainer of this work is Clea F. Rees.
%
% This work consists of all files listed in manifest.txt.
%
% The file fillwith.dtx is a derived work under the terms of the
% LPPL. It is based on version 2.4 of skeleton.dtx which is part of
% dtxtut by Scott Pakin. A copy of dtxtut, including the
% unmodified version of skeleton.dtx is available from
% https://www.ctan.org/pkg/dtxtut and released under the LPPL.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% \fi
%
% \iffalse
%<*driver>
\RequirePackage{svn-prov}
\ProvidesFileSVN{$Id: fillwith.dtx 10202 2024-08-08 15:33:47Z cfrees $}[v0.3 \revinfo][\filename: \filebase]
\DefineFileInfoSVN[fillwith]
\GetFileInfoSVN*
% ref. ateb Max Chernoff: https://tex.stackexchange.com/a/723294/ 
\def\MakePrivateLetters{\makeatletter\ExplSyntaxOn\endlinechar13}
\documentclass[british,a4paper]{ltxdoc}
\usepackage{babel}
\usepackage[tt={monowidth,lining,tabular},sf={lining,proportional},rm={lining,proportional}]{cfr-lm}
\usepackage{fillwith}
\usepackage{parskip}
\usepackage{verbatim}
\usepackage{graphicx}
\usepackage{xurl}
% sicrhau hyperindex=false: llwytho CYN bookmark
\usepackage{hypdoc}% ateb Ulrike Fischer: https://tex.stackexchange.com/a/695555/
\usepackage{bookmark}
\usepackage{cleveref}
\EnableCrossrefs
\CodelineIndex
\RecordChanges
%^^A \OnlyDescription
%^^A \ExplSyntaxOn
%^^A \makeatletter
\DoNotIndex{\verb,\ProvidesPackageSVN,\NeedsTeXFormat,\ProcessKeyOptions,\ExplSyntaxOn,\ExplSyntaxOff,\RequirePackage,\NeedsTeXFormat,\DefineFileInfoSVN,\GetInfoSVN,\@ifundefined,\@ifl@t@r\ExplLoaderFileDate,\endinput,\PackageError,\PackageWarning,\PackageInfo,\keys_define:nn,\keys_set:nn,\ProcessKeysOptionns,\author,\title,\maketitle,\date,\revinfo,\ProcessKeysOptions,\MessageBreak,\fmtversion,\documentclass,\ExplLoaderFileDate,\filebase,\fileversion,\fileinfo,\filebase:,\filedate,\documentclass,\@ifl@t@r,\begin,\end,\item,\IfFormatAtLeastTF}
%^^A \makeatother
%^^A \ExplSyntaxOff
\definecolor{strawberry}{rgb}{1.000,0.000,0.502}
\definecolor{blueberry}{rgb}{0.000,0.000,1.000}
\definecolor{moss}{rgb}{0.000,0.502,0.251}
\hypersetup{%
  colorlinks=true,
  citecolor={moss},
  extension=pdf,
  linkcolor={strawberry},
  linktocpage=true,
  pdfcreator={TeX},
  pdfproducer={pdfeTeX},
  urlcolor={blueberry}%
}
\NewDocElement[%
  idxtype=opt.,
  idxgroup=options,
  printtype=\textit{opt.},
]{Opt}{option}
\NewDocumentCommand \val { m }
{%
  {\ttfamily =\,\meta{#1}}%
}
\ExplSyntaxOn
\NewDocumentCommand \vals { m }
{
  {
    \ttfamily = \, 
    \clist_use:nn { #1 } { \textbar }
  }
} 
\ExplSyntaxOff
\setcounter{IndexColumns}{2}
\makeatletter
\def\@xobeysp{\leavevmode\penalty100\ }
\makeatother
\begin{document}
  \DocInput{\filename}
\end{document}
%</driver>
% \fi
% \title{\filebase{} \filerev}
% \author{Clea F. Rees}
% \date{\filedate}
% \maketitle
% \begin{abstract}
% A small package originally based on \href{https://tex.stackexchange.com/a/241139/}{Harish Kumar's answer} to a question I asked on \TeX{} SE\footnote{%
%   See \href{https://tex.stackexchange.com/a/241139/}{tex.stackexchange.com/a/241139/}.% 
% }.
% The intended purpose was the creation of worksheets for students where I would like \LaTeX{} to use the available vertical space to provide lined areas for answers.
% Since then, the code has been (partially) rewritten in \pkg{expl3} and extended in response to both my own needs and others' questions on \TeX{} SE.
% The package aims to do one thing: to fill a vertical space in the same way as, say, \verb|\vfill|, but with some kind of ‘filler’ rather than empty space.
% Currently, the package supports solid rules or dotted lines.
% The remainder of the current line may optionally be filled in the same way and the ‘filler’ may be coloured if desired.
% 
% Lines may optionally be numbered, though the numbered versions should not be used to fill long stretches as they are extremely inefficient.
% \textbf{Numbered fills are highly experimental and not recommended for use in ‘real’ documents.}
% That is, it seems to work, but I recommend using an alternative package or solution if you need a reliable numbering mechanism.
% \end{abstract}
% 
% \section{Load}\label{sec:pkg}
% To use the package simply load it in your preamble in the usual way.
%
% \iffalse
%<*verb>
% \fi
\begin{verbatim}
  \usepackage[<options>]{fillwith}
\end{verbatim}
% \iffalse
%</verb>
% \fi
%
% A small number of options may be specified when loading the package.
% See \cref{sec:config}.
%
% We start with an example in \cref{sec:ee}.
% \Cref{sec:use} describes the basic commands illustrated in this example.
% \Cref{sec:config} explains the options used by these commands, together with other customisation features of \pkg{fillwith}.
%
% \section{Example}\label{sec:ee}
%
% The code below illustrates most package features.
%
% \Cref{fig:ee1} demonstrates filling with rules.
% Note the effect of altering \texttt{fillwith ht} on line-spacing.
% \begin{figure}
%   \centering
%   \fbox{\includegraphics{fillwith-example.pdf}}
%   \caption{Filling with rules.}\label{fig:ee1}
% \end{figure}
%
% \Cref{fig:ee2} shows dotted fillings.
% Note the use of \cmd{\fillwithset} to alter the colour.
% \begin{figure}
%   \centering
%   \fbox{\includegraphics[page=2]{fillwith-example.pdf}}
%   \caption{Filling with dotted lines.}\label{fig:ee2}
% \end{figure}
%
% \Cref{fig:ee3} shows numbered fillings.
% Note the use of \texttt{goal ht} to divide the available vertical space more-or-less equally. 
% \begin{figure}
%   \centering
%   \fbox{\includegraphics[page=3]{fillwith-example.pdf}}
%   \caption{Filling with numbered lines.}\label{fig:ee3}
% \end{figure}
% 
% \verbatiminput{fillwith-example.tex}
% 
% \section{Usage}\label{sec:use}
%
% \DescribeMacro{\fillwith}\oarg{options}
% \DescribeMacro{\fillwith*}
% 
% Fill vertically with current settings, optionally modified by \meta{options}.
% See \cref{sec:config} for \meta{options}.
% If used in the middle of a line, the starred form fills to the end of the line first, whereas the unstarred form does not.
%
% \DescribeMacro{\fillwithrules}\oarg{line-spacing}
% \DescribeMacro{\fillwithrules*}
%
% Convenience wrappers which just set \texttt{style = rules} and set the line-spacing to \meta{line-spacing}.
% These macros do nothing which cannot be done using \cmd{\fillwith} and \cmd{\fillwith*}.
% 
% \DescribeMacro{\fillwithdottedlines}\oarg{line-spacing}
% \DescribeMacro{\fillwithdottedlines*}
%
% Convenience wrappers which just set \texttt{style = dots} and set the line-spacing to \meta{line-spacing}.
% These macros do nothing which cannot be done using \cmd{\fillwith} and \cmd{\fillwith*}.
% 
% \DescribeMacro{\fillwithnolines}\oarg{options}
% \DescribeMacro{\fillwithnolines*}
%
% Fill vertically with current settings, numbering each complete line, after optionally setting \meta{options}.
% Numbering \textbf{requires} use of these commands, as opposed to the generic \cmd{\fillwith}/\cmd{\fillwith*}.
% 
% \section{Customisation}\label{sec:config}
%
% Options can be set per use, locally or globally.
% A small number of options are implemented as package options (\cref{sec:pkg}).
%
% \DescribeMacro{\fillwithset}\marg{options}
% Set local or global defaults.
% 
% \DescribeOpt{colour}\val{colour name}
% \DescribeOpt{color}
% \DescribeOpt{lliw}
%
% Colour to be used for (solid) rules.
%
% Initially \texttt{gray}.
% Available as a package option.
%
% \DescribeOpt{dotted color}\val{colour name}
% \DescribeOpt{dotted colour}
%
% Colour to be used for dotted lines.
%
% Initially \texttt{black}.
% Available as a package option.
%
% \DescribeOpt{cont}\vals{true,false}
%
% Whether to fill the remainder of any current line.
% Generally, users will probably prefer to use the starred command forms for local usage, but this option permits modification of the package default on a local or global basis.
%
% Initially \texttt{false}.
% Default is \texttt{true}.
%
% \DescribeOpt{fillwith~ht}\val{real positive number expressed as decimal}
%
% Multiplication factor for line-spacing.
% Typically, hand-written content requires greater spacing than typewritten content.
% This option scales the standard line-spacing.
%
% Initially \texttt{2}, which is also the default value.
% Decimal values such as \texttt{1.5} are permitted.
%
% \DescribeOpt{goal ~ ht}\val{dimension}
%
% Used only by \cmd{\fillwithnolines} and \cmd{\fillwithnolines*}.
% Sets the target dimension to fill with numbered lines.
% If unspecified, the code tries to fill the remaining vertical space on the current page.
% If more than one use of a \pkg{fillwith} macro is used on a single page, this option \textbf{must} be used for numbered fills to prevent a single instance taking (almost) all available space.
% In contrast, multiple unnumbered fills can coexist on the same page without issue --- the available space will simply be divided equally between them.
%
% Initially unset.
% No default.
%
% \DescribeOpt{no ~ font}\val{font switches}
%
% Font switches to apply when typesetting numbers for numbered fills.
%
% Initially \cmd{\normalfont}\cmd{\normalsize}, which is also the default value.
% Note the commands used here should be switches rather than text commands -- for example, use \cmd{\bfseries} rather than \cmd{\textbf} --- since the commands should not expect an argument.
%
% \DescribeOpt{style}\vals{rule,dots,line,lines,rules}
%
% Style of fill.
% \texttt{rule}, \texttt{line}, \texttt{rules} and \texttt{lines} are synonyms which all denote solid rules or lines.
% \texttt{dots} uses dotted lines rather than solid rules.
% The dots are slightly more densely packed than the standard used for dotted fills by the standard classes, as these seem a bit too widely spaced to provide ideal guidelines.
%
% Initially \texttt{dots}, which is also the default value.
%
% If an unknown value is used, the code will attempt to use two macros derived from that value.
% The first is constructed simply by preceding \meta{value} with a backslash and the second by also appending \texttt{part}.
% For example, if \texttt{style}\val{mystyle} is used, the code will try to use \cs{mystyle} and \cs{mystylepart} for complete and partial lines.
% In theory, this supports filling with somewhat arbitrary content, but the implementation is untested and \textbf{should not be used in real documents}.
%
% 
% \changes{v0.0}{???}{First public release.}
% \changes{\fileversion}{\filedate}{}
%  
%
% \MaybeStop{%
% \PrintChanges
% \PrintIndex
% }
% 
% \section{Implementation}
%
% You do not need to read the remainder of this document in order to install or use the package.
%
% \iffalse
%<@@=fillwith>
%<*sty>
% \fi
%    \begin{macrocode}
\NeedsTeXFormat{LaTeX2e}[2021-11-15]
\RequirePackage{svn-prov}
\ProvidesPackageSVN[\filebase.sty]{$Id: fillwith.dtx 10202 2024-08-08 15:33:47Z cfrees $}[v0.0 \revinfo][\filebase: fill vertically with non-space]
% this is needed only because l3doc overwrites \fileversion and \filedate
% neither ltxdoc nor doc does this
\DefineFileInfoSVN
%    \end{macrocode}
% \iffalse
% ^^A Paid â defnyddio \GetFileInfoSVN*/\GetFileInfoSVN{} yn y fan hon!!
% \fi
%    \begin{macrocode}
\RequirePackage{xcolor}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% copied verbatim, excepting format from Joseph Wright's' siunitx.sty under LPPL
\@ifundefined{ExplLoaderFileDate}{%
  \RequirePackage{expl3}%
}{}
% almost verbatim from siunitx.sty
\@ifl@t@r\ExplLoaderFileDate{2022-02-24}{%
}{%
  \PackageError{fillwith}{Support package expl3 too old}
  {%
    You need to update your installation of the bundles 'l3kernel' and
    'l3packages'.\MessageBreak
    Loading~fillwith~will~abort!%
  }%
  \endinput
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ExplSyntaxOn
\prop_gput:Nnn \g_msg_module_name_prop { fillwith } { fillwith }

% BEGIN Expl pkg option setup

\keys_define:nn { fillwith }
{
  color .meta:n = {
    colour = #1,
  },
  colour .code:n = {
    \colorlet{fillwithcolour}{#1}
  },
  dotted ~ color .meta:n = {
    dotted colour = #1,
  },
  dotted color .meta:n = {
    dotted colour = #1,
  },
  dotted ~ colour .meta:n = {
    dotted colour = #1,
  },
  dotted colour .code:n = {
    \colorlet{fillwithdottedcolour}{#1}
  },
  lliw .meta:n = {
    colour = #1,
  },
  colour .initial:n = gray,
  dotted colour .initial:n = black,
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Joseph Wright: from siunitx.sty ; https://chat.stackexchange.com/transcript/message/64327823#64327823
\providecommand \IfFormatAtLeastTF { \@ifl@t@r \fmtversion }
\IfFormatAtLeastTF { 2022-06-01 }
{
  \ProcessKeyOptions [ fillwith ]
}{
  \RequirePackage { l3keys2e }
  \ProcessKeysOptions { fillwith }
}
\IfFormatAtLeastTF { 2020-10-01 }{
}{
  \RequirePackage { xparse }
  \providecommand \ExpandArgs [1]
  { \cs_if_exist_use:c { exp_args:N #1 } }
}
% END Expl pkg option setup
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% BEGIN vars
\box_new:N \l__fillwith_adj_rule_box
\box_new:N \l__fillwith_part_rule_box
\box_new:N \l__fillwith_tmpa_box
\box_new:N \l__fillwith_tmpb_box
% BEGIN coffins
\coffin_new:N \l__fillwith_line_coffin
\coffin_new:N \l__fillwith_lines_coffin
\coffin_new:N \l__fillwith_part_coffin
\coffin_new:N \l__fillwith_tmpa_coffin
% END coffins
% BEGIN dims
\dim_new:N \l__fillwith_ht_dim
\dim_new:N \l__fillwith_dp_dim
\dim_new:N \l__fillwith_rem_dim
\dim_new:N \l__fillwith_line_ht_dim
\dim_new:N \l__fillwith_line_adj_hsize_dim
\dim_set:Nn \l__fillwith_line_ht_dim { 0.4pt }
\dim_new:N \l__fillwith_line_madj_dim
\dim_new:N \l__fillwith_line_vadj_dim
\dim_set_eq:NN \l__fillwith_line_vadj_dim \c_zero_dim
\dim_new:N \l__fillwith_goal_dim
\dim_new:N \l__fillwith_tmpa_dim
% END dims
\int_new:N \g__fillwith_cnt_int
% END vars
% BEGIN fns
\cs_new_protected_nopar:Nn \__fillwith_style: {}
\cs_new_protected_nopar:Nn \__fillwith_coffin_tht:N
{
  \dim_eval:n { \coffin_ht:N #1 + \coffin_dp:N #1 }
}
% BEGIN \__fillwith_hrulefill:
\cs_new_protected_nopar:Npn \__fillwith_hrulefill_part:
{
  \vrule height \c_zero_dim depth \l__fillwith_line_ht_dim width 0.1pt
}
\cs_new_protected_nopar:Npn \__fillwith_hrulefill:
{
  \vrule height \c_zero_dim depth \l__fillwith_line_ht_dim width \l__fillwith_line_adj_hsize_dim
}
% END \__fillwith_hrulefill:
% BEGIN \__fillwith_dottedfill:
\cs_new_protected_nopar:Npn \__fillwith_dottedfill_part:
{
  \hbox to 0.33em {\hss .\hss}
}
\cs_new_protected_nopar:Npn \__fillwith_dottedfill:
{
  \leaders \hbox to 0.33em {\hss .\hss} \hfill \kern \c_zero_dim
}
% END \__fillwith_dottedfill:
% END fns
%    \end{macrocode}
% \begin{macro}{\fillwithset}
% Wrapper command for configuration.
% Most global or local customisation will use this as most keys are not valid package options.
%    \begin{macrocode}
\NewDocumentCommand\fillwithset { +m }{
  \keys_set:nn { fillwith } { #1 }
}
%    \end{macrocode}
% \end{macro}
%    \begin{macrocode}
% BEGIN keys (+)
\keys_define:nn { fillwith }
{
  cont .bool_set:N = \l__fillwith_cont_bool,
  cont .default:n = true,
  cont .initial:n = false,
  fillwith~ht .tl_set:N = \l__fillwith_ht_tl,
  fillwith~ht .initial:n = 2,
  fillwith~ht .default:n = 2,
  goal ~ ht .dim_set:N = \l__fillwith_goal_dim,
  line nos .bool_set:N = \l__fillwith_nos_bool,
  line ~ nos .bool_set:N = \l__fillwith_nos_bool,
  line ~ nos .default:n = true,
  line ~ nos .initial:n = false,
  no ~ font .tl_set:N = \l__fillwith_no_font_tl,
  no ~ font .initial:n = { \normalfont\normalsize },
  no ~ font .default:n = { \normalfont\normalsize },
  style .choices:nn =
  {
    rule,  dots , line , lines , rules , unknown
  }{
    \if_case:w \l_keys_choice_int
      \or: \cs_set_eq:NN \__fillwith_style: \__fillwith_hrulefill:
      \or: \cs_set_eq:NN \__fillwith_style: \__fillwith_dottedfill:
      \or: \cs_set_eq:NN \__fillwith_style: \__fillwith_hrulefill:
      \or: \cs_set_eq:NN \__fillwith_style: \__fillwith_hrulefill:
      \or: \cs_set_eq:NN \__fillwith_style: \__fillwith_hrulefill:
      \else: \cs_set_protected_nopar:Nn \__fillwith_style: { \use:c { \l_keys_choice_tl } }
    \fi:
    \if_case:w \l_keys_choice_int
      \or: \cs_set_eq:NN \__fillwith_style_part: \__fillwith_hrulefill_part:
      \or: \cs_set_eq:NN \__fillwith_style_part: \__fillwith_dottedfill_part:
      \or: \cs_set_eq:NN \__fillwith_style_part: \__fillwith_hrulefill_part:
      \or: \cs_set_eq:NN \__fillwith_style_part: \__fillwith_hrulefill_part:
      \or: \cs_set_eq:NN \__fillwith_style_part: \__fillwith_hrulefill_part:
      \else: \cs_set_protected_nopar:Nn \__fillwith_style_part: { \use:c { \l_keys_choice_tl part } }
    \fi:
  },
  style .default:n = dots,
  style .initial:n = dots,
}
% END keys (+)
% 
% BEGIN \__fillwith_fill:
% ref: https://tex.stackexchange.com/a/241139/ Harish Kumar
\cs_new_protected_nopar:Nn \__fillwith_fill:
{
  \__fillwith_measures:
  \dim_set:Nn \l__fillwith_line_adj_hsize_dim { \hsize - \@totalleftmargin }
  \vbox_set:Nn \l__fillwith_adj_rule_box
  {
    \parindent=0pt
    \vrule height \l__fillwith_ht_dim depth \l__fillwith_dp_dim width \c_zero_dim
    \skip_horizontal:n { \@totalleftmargin }
    \__fillwith_style:
  }
  \if_mode_horizontal:
    \bool_if:NT \l__fillwith_cont_bool
    {
      \leaders \box_use:N \l__fillwith_part_rule_box  \hfill \kern \c_zero_dim
    }{
      \vrule height \l__fillwith_ht_dim depth \l__fillwith_dp_dim width \c_zero_dim
    }
    %^^A gweithio ond erbyn y rheolau
    %^^A byddai'n achosi draferth, siwr o fod
    % \tex_par:D
    %^^A yn lle hynny, ceisio hyn - oes perygl hefyd?
    \para_raw_end:
  \else:
    \unskip
    \skip_vertical:n { \l__fillwith_dp_dim }
  \fi:
  \xleaders \box_use:N \l__fillwith_adj_rule_box  \vfill
  \para_end:
  \normalcolor
}
% END \__fillwith_fill:
% BEGIN \__fillwith_measures:
\cs_new_protected_nopar:Nn \__fillwith_measures:
{
  \color{fillwithcolour}
  \offinterlineskip
  \hbox_set:Nn \l__fillwith_part_rule_box
  {
    \strut
    \__fillwith_style_part:
    \kern \c_zero_dim
  }
  \dim_set:Nn \l__fillwith_tmpa_dim { \box_ht:N \l__fillwith_part_rule_box }
  \dim_set:Nn \l__fillwith_ht_dim { \l__fillwith_ht_tl  \l__fillwith_tmpa_dim }
  \box_set_ht:Nn \l__fillwith_part_rule_box { \l__fillwith_ht_dim }
  \dim_set:Nn \l__fillwith_tmpa_dim { \box_dp:N \l__fillwith_part_rule_box }
  % neu  \fp_to_dim:n { \l__fillwith_ht_tl * \l__fillwith_tmpa_dim } ??
  \dim_set:Nn \l__fillwith_dp_dim { \l__fillwith_ht_tl  \l__fillwith_tmpa_dim }
  \box_set_dp:Nn \l__fillwith_part_rule_box { \l__fillwith_dp_dim }
}
% END \__fillwith_measures:
% BEGIN fillwith
%    \end{macrocode}
% \begin{macro}{\fillwith}
% The package is basically this macro.
%    \begin{macrocode}
\NewDocumentCommand \fillwith { s o }
{
  \group_begin:
    \IfValueT { #2 }
    {
      \keys_set:nn { fillwith } { #2 }
    }
    \IfBooleanTF { #1 }
    {
      \bool_set_true:N \l__fillwith_cont_bool
    }{
      \bool_set_false:N \l__fillwith_cont_bool
    }
    \__fillwith_fill:
  \group_end:
}
%    \end{macrocode}
% \end{macro}
%    \begin{macrocode}
% END fillwith
% BEGIN fillwithrules
%    \end{macrocode}
% \begin{macro}{\fillwithrules}
% Simple convenience wrapper with simplified syntax for (solid) rules.
%    \begin{macrocode}
\NewDocumentCommand \fillwithrules { s O { 2 } }
{
  \group_begin:
    \IfBooleanTF { #1 }
    {
      \bool_set_true:N \l__fillwith_cont_bool
    }{
      \bool_set_false:N \l__fillwith_cont_bool
    }
    \keys_set:nn { fillwith } { style = rules, fillwith~ht=#2 }
    \__fillwith_fill:
  \group_end:
}
%    \end{macrocode}
% \end{macro}
%    \begin{macrocode}
% END fillwithrules
% BEGIN fillwithdottedlines
%    \end{macrocode}
% \begin{macro}{\fillwithdottedlines}
% Simple convenience wrapper with simplified syntax for dotted lines.
%    \begin{macrocode}
\NewDocumentCommand \fillwithdottedlines { s O { 2 } }
{
  \group_begin:
    \IfBooleanTF { #1 }
    {
      \bool_set_true:N \l__fillwith_cont_bool
    }{
      \bool_set_false:N \l__fillwith_cont_bool
    }
    \colorlet{fillwithcolour}{fillwithdottedcolour}
    \keys_set:nn { fillwith } { style = dots, fillwith~ht=#2 }
    \__fillwith_fill:
  \group_end:
}
%    \end{macrocode}
% \end{macro}
%    \begin{macrocode}
% END fillwithdottedlines
% BEGIN fillwithnolines
\cs_new_protected:Nn \__fillwith_nos: % rhybudd: ARAF ! SLOW!
{
  \parindent=0pt
  \__fillwith_measures:
  \dim_set_eq:NN \l__fillwith_line_adj_hsize_dim \linewidth
  \vcoffin_set:Nnn \l__fillwith_line_coffin { \l__fillwith_line_adj_hsize_dim }
  {
    \parindent=0pt
    \vrule height \l__fillwith_ht_dim depth \l__fillwith_dp_dim width \c_zero_dim
    \skip_horizontal:n \c_zero_skip
    \__fillwith_style:
  }
  \coffin_set_eq:NN \l__fillwith_lines_coffin \l__fillwith_line_coffin
  \if_mode_horizontal:
    \bool_if:NTF \l__fillwith_cont_bool
    {
      \leaders \box_use:N \l__fillwith_part_rule_box  \hfill \kern \c_zero_dim
      \int_gincr:N \g__fillwith_cnt_int
      % \vcoffin_set:Nnn \l__fillwith_tmpa_coffin  { 1.5em} 
      % {
      %   \l__fillwith_no_font_tl \int_to_arabic:n { \g__fillwith_cnt_int } 
      % }
      % \coffin_mark_handle:Nnnn \l__fillwith_tmpa_coffin {B} {l} { red }
      % \coffin_mark_handle:Nnnn \l__fillwith_tmpa_coffin {b} {l} { green }
      % \coffin_attach:NnnNnnnn \l__fillwith_lines_coffin {B} {r} \l__fillwith_tmpa_coffin {B} {l} {2.5pt} { \l__fillwith_ht_dim + \l__fillwith_dp_dim }
      % \coffin_mark_handle:Nnnn \l__fillwith_lines_coffin {T} {r} { blue }
      % \coffin_mark_handle:Nnnn \l__fillwith_lines_coffin {t} {r} { magenta }
      \dim_set:Nn \l__fillwith_line_vadj_dim { \l__fillwith_dp_dim }
    }{
      \vrule height \l__fillwith_ht_dim depth \l__fillwith_dp_dim width \c_zero_dim
    }
    \dim_set:Nn \l__fillwith_line_madj_dim { \@totalleftmargin }
    \para_raw_end:
  \else:
    \dim_set_eq:NN \l__fillwith_line_madj_dim \c_zero_dim
    \unskip
    \skip_vertical:n { \l__fillwith_dp_dim }
  \fi:
  \int_gincr:N \g__fillwith_cnt_int
  \vcoffin_set:Nnn \l__fillwith_tmpa_coffin  { 1.5em} 
  {
    \l__fillwith_no_font_tl \int_to_arabic:n { \g__fillwith_cnt_int } 
  }
  \coffin_attach:NnnNnnnn \l__fillwith_lines_coffin {B} {r} \l__fillwith_tmpa_coffin {B} {l} {2.5pt} {\c_zero_dim}
  \dim_set:Nn \l__fillwith_rem_dim 
  {
    \l__fillwith_goal_dim -\footskip - \pagetotal  
  }
  \dim_until_do:nNnn { \__fillwith_coffin_tht:N \l__fillwith_lines_coffin } > { \l__fillwith_rem_dim - \l__fillwith_ht_dim - \l__fillwith_dp_dim }
  {
    \coffin_join:NnnNnnnn \l__fillwith_lines_coffin { b } { l } \l__fillwith_line_coffin { t } { l } { \c_zero_dim } { \c_zero_dim }
    \int_gincr:N \g__fillwith_cnt_int
    \vcoffin_set:Nnn \l__fillwith_tmpa_coffin  {1.5em} 
    {
      \l__fillwith_no_font_tl \int_to_arabic:n { \g__fillwith_cnt_int } 
    }
    \coffin_attach:NnnNnnnn \l__fillwith_lines_coffin {B} {r} \l__fillwith_tmpa_coffin {B} {l} {2.5pt} {\c_zero_dim}
  }
  \coffin_typeset:Nnnnn \l__fillwith_lines_coffin { B } { l } { \l__fillwith_line_madj_dim } { \l__fillwith_line_vadj_dim }
  \para_end:
  \normalcolor
}
%    \end{macrocode}
% \begin{macro}{\fillwithnolines}
% Provisional experimental macro for numbered fill.
%    \begin{macrocode}
\NewDocumentCommand \fillwithnolines { s O { } }
{
  \group_begin:
    \IfBooleanTF { #1 }
    {
      \bool_set_true:N \l__fillwith_cont_bool
    }{
      \bool_set_false:N \l__fillwith_cont_bool
    }
    \keys_set:nn { fillwith } {  goal ~ ht = \pagegoal, #2 }
    \__fillwith_nos:
  \group_end:
}
%    \end{macrocode}
% \end{macro}
%    \begin{macrocode}
% END fillwithnolines
\ExplSyntaxOff
%    \end{macrocode}
% \iffalse
%</sty>
% \fi
% 
% \subsection{Demonstration}
% 
% Simple example to demonstrate usage.
%
% \iffalse
%<*ee>
% \fi
%    \begin{macrocode}
\listfiles
\documentclass[british,a6paper]{article}
\usepackage{babel}
\usepackage[scale=.85,marginparwidth=0pt,marginparsep=0pt]{geometry}
\usepackage{fillwith}
\usepackage{cfr-lm}
\begin{document}
\author{A. N. Author}
\title{\texttt{fillwith} Demo}
\maketitle
\begin{enumerate}
  \item What is the answer to the question?
    \fillwithrules
  \item How did you answer the previous question?
    \fillwith*[style=line]
  \item Why answer?

    \fillwith*[style=rule,fillwith ht=1.25,colour=blue!40!cyan]
    \clearpage
  \item Evaluate your responses so far.
    \fillwithdottedlines
  \item Evaluate your responses so far.

    {%
      \fillwithset{dotted colour=magenta}%
      \fillwithdottedlines[1.5]
    }
  \item Criticise your evaluation.
    \fillwithdottedlines*
    \clearpage
  \item Assess your answers.
    \fillwithnolines[goal ht = .33\textheight]
  \item Assess your answers.

    \fillwithnolines[style=rules,no font=\bfseries\tiny,colour=green!50!gray,goal ht = .67\textheight]
  \item Summarise your analysis.
    \fillwithnolines*
\end{enumerate}

\end{document}
%    \end{macrocode}
% \iffalse
%</ee>
% \fi
% \subsection{Other}
% \iffalse
%<*other>
% \fi
%    \begin{macrocode}
%    \end{macrocode}
% \iffalse
%</other>
% \fi
%\Finale