% arara: pdflatex: { files: [latexindent]}
\section{Fine tuning}\label{sec:finetuning}
 \texttt{latexindent.pl} operates by looking for the code blocks detailed in
 \vref{tab:code-blocks}.
 \announce{2019-07-13}{details of fine tuning of code blocks} The fine tuning of the
 details of such code blocks is controlled by the \texttt{fineTuning} field, detailed in
 \cref{lst:fineTuning}.

 This field is for those that would like to peek under the bonnet/hood and make some fine
 tuning to \texttt{latexindent.pl}'s operating. \index{warning!fine tuning} \index{regular
 expressions!fine tuning} \index{regular expressions!environments} \index{regular
 expressions!ifElseFi} \index{regular expressions!commands} \index{regular
 expressions!keyEqualsValuesBracesBrackets} \index{regular
 expressions!NamedGroupingBracesBrackets} \index{regular
 expressions!UnNamedGroupingBracesBrackets} \index{regular expressions!arguments}
 \index{regular expressions!modifyLineBreaks} \index{regular expressions!lowercase alph
 a-z} \index{regular expressions!uppercase alph A-Z} \index{regular expressions!numeric
 0-9} \index{regular expressions!at least one +} \index{regular expressions!horizontal
 space \textbackslash{h}}

 \begin{warning}
	 Making changes to the fine tuning may have significant consequences for your indentation
	 scheme, proceed with caution!
 \end{warning}

 \begin{widepage}
	 \cmhlistingsfromfile[style=fineTuning]{../defaultSettings.yaml}[width=.95\linewidth,before=\centering,yaml-TCB]{\texttt{fineTuning}}{lst:fineTuning}
 \end{widepage}

 The fields given in \cref{lst:fineTuning} are all \emph{regular expressions}. This manual
 is not intended to be a tutorial on regular expressions; you might like to read, for
 example, \cite{masteringregexp} for a detailed covering of the topic.

 We make the following comments with reference to \cref{lst:fineTuning}:
 \begin{enumerate}
	 \item the \texttt{environments:name} field details that the \emph{name} of an environment can
	       contain:
	       \begin{enumerate}
		       \item \texttt{a-z} lower case letters
		       \item \texttt{A-Z} upper case letters
		       \item \texttt{@} the \texttt{@} 'letter'
		       \item \lstinline!\*! stars
		       \item \texttt{0-9} numbers
		       \item \lstinline!_! underscores
		       \item \lstinline!\! backslashes
	       \end{enumerate}
	       \index{regular expressions!at least one +}
	       The \texttt{+} at the end means \emph{at least one} of the above characters.
	 \item the \texttt{ifElseFi:name} field:
	       \begin{enumerate}
		       \item \lstinline^@?^ means that it \emph{can possibly} begin with
		             \lstinline^@^
		       \item followed by \texttt{if}
		       \item followed by 0 or more characters from \texttt{a-z}, \texttt{A-Z} and \texttt{@}
		       \item the \texttt{?} the end means \emph{non-greedy}, which means `stop the match as soon as
		             possible'
	       \end{enumerate}
	 \item the \texttt{keyEqualsValuesBracesBrackets} contains some interesting syntax:
	       \begin{enumerate}
		       \item \lstinline!|! means `or'
		       \item \lstinline^(?:(?<!\\)\{)^ the \lstinline^(?:...)^ uses a \emph{non-capturing} group -- you don't necessarily need to worry about what this
		             means, but just know that for the \texttt{fineTuning} feature you should only ever use
		             \emph{non}-capturing groups, and \emph{not} capturing groups, which are simply
		             \lstinline!(...)!
		       \item \lstinline^(?<!\\)\{)^ means a \lstinline^{^ but it can \emph{not} be immediately preceded by a \lstinline!\!
	       \end{enumerate}
	 \item in the \texttt{arguments:before} field
	       \begin{enumerate}
		       \item \lstinline^\d\h*^ means a digit (i.e. a number), followed by 0 or more horizontal spaces
		       \item \lstinline^;?,?^ means \emph{possibly} a semi-colon, and possibly a comma
		       \item \lstinline^\<.*?\>^ is designed for 'beamer'-type commands; the
		             \lstinline^.*?^ means anything in between \lstinline^<...>^
	       \end{enumerate}
	 \item the \texttt{modifyLineBreaks} field refers to fine tuning settings detailed in
	       \vref{sec:modifylinebreaks}. In particular:
	       \begin{enumerate}
		       \item \texttt{betterFullStop} is in relation to the one sentence per line routine, detailed in
		             \vref{sec:onesentenceperline}
		       \item \texttt{doubleBackSlash} is in relation to the \texttt{DBSStartsOnOwnLine} and
		             \texttt{DBSFinishesWithLineBreak} polyswitches surrounding double back slashes, see
		             \vref{subsec:dbs}
		       \item \texttt{comma} is in relation to the \texttt{CommaStartsOnOwnLine} and
		             \texttt{CommaFinishesWithLineBreak} polyswitches surrounding commas in optional and
		             mandatory arguments; see \vref{tab:poly-switch-mapping}
	       \end{enumerate}
 \end{enumerate}

 It is not obvious from \cref{lst:fineTuning}, but each of the \texttt{follow},
 \texttt{before} and \texttt{between} fields allow trailing comments, line breaks, and
 horizontal spaces between each character.

 \index{warning!capture groups}
 \begin{warning}
	 For the \texttt{fineTuning} feature you should only ever use \emph{non}-capturing groups,
	 such as \lstinline!(?:...)! and \emph{not} capturing groups, which are \lstinline!(...)!
 \end{warning}

 \begin{example}
	 As a demonstration, consider the file given in \cref{lst:finetuning1}, together with its
	 default output using the command
	 \begin{commandshell}
latexindent.pl finetuning1.tex 
\end{commandshell}
	 is given in \cref{lst:finetuning1-default}.

	 \begin{cmhtcbraster}[raster column skip=.01\linewidth]
		 \cmhlistingsfromfile{demonstrations/finetuning1.tex}{\texttt{finetuning1.tex}}{lst:finetuning1}
		 \cmhlistingsfromfile{demonstrations/finetuning1-default.tex}{\texttt{finetuning1.tex} default}{lst:finetuning1-default}
	 \end{cmhtcbraster}

	 It's clear from \cref{lst:finetuning1-default} that the indentation scheme has not worked
	 as expected. We can \emph{fine tune} the indentation scheme by employing the settings
	 given in \cref{lst:fine-tuning1} and running the command \index{switches!-l
	 demonstration}
	 \begin{commandshell}
latexindent.pl finetuning1.tex -l=fine-tuning1.yaml
\end{commandshell}
	 and the associated (desired) output is given in \cref{lst:finetuning1-mod1}.
	 \index{regular expressions!at least one +}

	 \begin{cmhtcbraster}[raster column skip=.01\linewidth]
		 \cmhlistingsfromfile{demonstrations/finetuning1-mod1.tex}{\texttt{finetuning1.tex} using \cref{lst:fine-tuning1}}{lst:finetuning1-mod1}
		 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/fine-tuning1.yaml}[yaml-TCB]{\texttt{finetuning1.yaml}}{lst:fine-tuning1}
	 \end{cmhtcbraster}
 \end{example}

 \begin{example}
	 Let's have another demonstration; consider the file given in \cref{lst:finetuning2},
	 together with its default output using the command
	 \begin{commandshell}
latexindent.pl finetuning2.tex 
\end{commandshell}
	 is given in \cref{lst:finetuning2-default}.

	 \begin{cmhtcbraster}[raster column skip=.01\linewidth,
			 raster left skip=-3.75cm,
			 raster right skip=0cm,]
		 \cmhlistingsfromfile{demonstrations/finetuning2.tex}{\texttt{finetuning2.tex}}{lst:finetuning2}
		 \cmhlistingsfromfile{demonstrations/finetuning2-default.tex}{\texttt{finetuning2.tex} default}{lst:finetuning2-default}
	 \end{cmhtcbraster}

	 It's clear from \cref{lst:finetuning2-default} that the indentation scheme has not worked
	 as expected. We can \emph{fine tune} the indentation scheme by employing the settings
	 given in \cref{lst:fine-tuning2} and running the command \index{switches!-l
	 demonstration}
	 \begin{commandshell}
latexindent.pl finetuning2.tex -l=fine-tuning2.yaml
\end{commandshell}
	 and the associated (desired) output is given in \cref{lst:finetuning2-mod1}.

	 \begin{cmhtcbraster}[raster column skip=.01\linewidth,
			 raster left skip=-3.75cm,
			 raster right skip=0cm,]
		 \cmhlistingsfromfile{demonstrations/finetuning2-mod1.tex}{\texttt{finetuning2.tex} using \cref{lst:fine-tuning2}}{lst:finetuning2-mod1}
		 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/fine-tuning2.yaml}[yaml-TCB]{\texttt{finetuning2.yaml}}{lst:fine-tuning2}
	 \end{cmhtcbraster}

	 In particular, note that the settings in \cref{lst:fine-tuning2} specify that
	 \texttt{NamedGroupingBracesBrackets} and \texttt{UnNamedGroupingBracesBrackets} can
	 follow \texttt{"} and that we allow \lstinline!---! between arguments.
 \end{example}

 \begin{example}
	 You can tweak the \texttt{fineTuning} using the \texttt{-y} switch, but to be sure to use
	 quotes appropriately. For example, starting with the code in \cref{lst:finetuning3} and
	 running the following command
	 \begin{commandshell}
latexindent.pl -m -y='modifyLineBreaks:oneSentencePerLine:manipulateSentences: 1, modifyLineBreaks:oneSentencePerLine:sentencesBeginWith:a-z: 1, fineTuning:modifyLineBreaks:betterFullStop: "(?:\.|;|:(?![a-z]))|(?:(?<!(?:(?:e\.g)|(?:i\.e)|(?:etc))))\.(?!(?:[a-z]|[A-Z]|\-|~|\,|[0-9]))"' issue-243.tex -o=+-mod1
\end{commandshell}
	 gives the output shown in \cref{lst:finetuning3-mod1}.

	 \cmhlistingsfromfile{demonstrations/finetuning3.tex}{\texttt{finetuning3.tex}}{lst:finetuning3}
	 \cmhlistingsfromfile{demonstrations/finetuning3-mod1.tex}{\texttt{finetuning3.tex} using -y switch}{lst:finetuning3-mod1}
 \end{example}

 \begin{example}
	 We can tweak the \texttt{fineTuning} for how trailing comments are classified. For
	 motivation, let's consider the code given in \cref{lst:finetuning4}

	 \cmhlistingsfromfile{demonstrations/finetuning4.tex}{\texttt{finetuning4.tex}}{lst:finetuning4}

	 We will compare the settings given in \cref{lst:href1,lst:href2}.

	 \begin{cmhtcbraster}[raster column skip=.01\linewidth,
			 raster left skip=0cm,
			 raster right skip=-0.5cm,]
		 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/href1.yaml}[MLB-TCB]{\texttt{href1.yaml}}{lst:href1}
		 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/href2.yaml}[MLB-TCB]{\texttt{href2.yaml}}{lst:href2}
	 \end{cmhtcbraster}

	 Upon running the following commands
	 \begin{commandshell}
latexindent.pl -m finetuning4.tex -o=+-mod1 -l=href1
latexindent.pl -m finetuning4.tex -o=+-mod2 -l=href2
\end{commandshell}
	 we receive the respective output in \cref{lst:finetuning4-mod1,lst:finetuning4-mod2}.

	 \begin{widepage}
		 \cmhlistingsfromfile{demonstrations/finetuning4-mod1.tex}{\texttt{finetuning4.tex} using \cref{lst:href1}}{lst:finetuning4-mod1}

		 \cmhlistingsfromfile{demonstrations/finetuning4-mod2.tex}{\texttt{finetuning4.tex} using \cref{lst:href2}}{lst:finetuning4-mod2}
	 \end{widepage}

	 We note that in:
	 \begin{itemize}
		 \item \cref{lst:finetuning4-mod1} the trailing comments are assumed to be everything following
		       the first comment symbol, which has meant that everything following it has been moved to
		       the end of the line; this is undesirable, clearly!
		 \item \cref{lst:finetuning4-mod2} has fine-tuned the trailing comment matching, and says that
		       \% cannot
		       be immediately preceeded by the words `Handbook', `for' or `Spoken', which means that
		       none of the \% symbols have been treated as trailing comments, and the output is
		       desirable.
	 \end{itemize}

	 Another approach to this situation, which does not use \texttt{fineTuning}, is to use
	 \texttt{noIndentBlock} which we discussed in \vref{lst:noIndentBlock}; using the settings
	 in \cref{lst:href3} and running the command
	 \begin{commandshell}
latexindent.pl -m finetuning4.tex -o=+-mod3 -l=href3
\end{commandshell}
	 then we receive the same output given in \cref{lst:finetuning4-mod2}.

	 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/href3.yaml}[MLB-TCB]{\texttt{href3.yaml}}{lst:href3}

	 With reference to the \texttt{body} field in \cref{lst:href3}, we note that the
	 \texttt{body} field can be interpreted as: the fewest number of zero or more characters
	 that are not right braces. This is an example of character class. \index{regular
	 expressions!character class demonstration}
 \end{example}

 \begin{example}
	 We can use the \texttt{fineTuning} field to assist in the formatting of bibliography
	 files. \index{bibliography files} \index{regular expressions!delimiterRegEx}
	 \index{regular expressions!capturing parenthesis} \index{regular expressions!ampersand
	 alignment} \index{delimiters!delimiterRegEx}

	 Starting with the file in \cref{lst:bib1} and running the command
	 \begin{commandshell}
latexindent.pl bib1.tex -o=+-mod1 
   \end{commandshell}
	 gives the output in \cref{lst:bib1-mod1}.

	 \begin{widepage}
		 \begin{cmhtcbraster}[raster column skip=.01\linewidth]
			 \cmhlistingsfromfile{demonstrations/bib1.bib}{\texttt{bib1.bib}}{lst:bib1}
			 \cmhlistingsfromfile{demonstrations/bib1-mod1.bib}{\texttt{bib1-mod1.bib}}{lst:bib1-mod1}
		 \end{cmhtcbraster}
	 \end{widepage}

	 Let's assume that we would like to format the output so as to align the \texttt{=}
	 symbols. Using the settings in \cref{lst:bibsettings1} and running the command
	 \begin{commandshell}
latexindent.pl bib1.bib -l bibsettings1.yaml -o=+-mod2 
     \end{commandshell}
	 gives the output in \cref{lst:bib1-mod2}.

	 \begin{widepage}
		 \begin{cmhtcbraster}[raster column skip=.1\linewidth]
			 \cmhlistingsfromfile{demonstrations/bib1-mod2.bib}{\texttt{bib1.bib} using \cref{lst:bibsettings1}}{lst:bib1-mod2}
			 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/bibsettings1.yaml}[yaml-TCB]{\texttt{bibsettings1.yaml}}{lst:bibsettings1}
		 \end{cmhtcbraster}
	 \end{widepage}
	 Some notes about \cref{lst:bibsettings1}:
	 \begin{itemize}
		 \item we have populated the \texttt{lookForAlignDelims} field with the \texttt{online} command,
		       and have used the \texttt{delimiterRegEx}, discussed in \vref{sec:delimiter-reg-ex};
		 \item we have tweaked the \texttt{keyEqualsValuesBracesBrackets} code block so that it will
		       \emph{not} be found following a comma; this means that, in contrast to the default
		       behaviour, the lines such as \lstinline!date={2013-05-23},! will \emph{not} be treated as
		       key-equals-value braces;
		 \item the adjustment to \texttt{keyEqualsValuesBracesBrackets} necessitates the associated
		       change to the \texttt{UnNamedGroupingBracesBrackets} field so that they will be searched
		       for following \texttt{=} symbols.
	 \end{itemize}
 \end{example}

 \begin{example}
	 We can build upon \cref{lst:bibsettings1} for slightly more complicated bibliography
	 files.

	 Starting with the file in \cref{lst:bib2} and running the command
	 \begin{commandshell}
latexindent.pl bib2.bib -l bibsettings1.yaml -o=+-mod1 
   \end{commandshell}
	 gives the output in \cref{lst:bib2-mod1}.

	 \begin{widepage}
		 \cmhlistingsfromfile{demonstrations/bib2.bib}{\texttt{bib2.bib}}{lst:bib2}
		 \cmhlistingsfromfile{demonstrations/bib2-mod1.bib}{\texttt{bib2-mod1.bib}}{lst:bib2-mod1}
	 \end{widepage}

	 The output in \cref{lst:bib2-mod1} is not ideal, as the \texttt{=} symbol within the url
	 field has been incorrectly used as an alignment delimiter.

	 We address this by tweaking the \texttt{delimiterRegEx} field in \cref{lst:bibsettings2}.

	 \cmhlistingsfromfile[style=yaml-LST]{demonstrations/bibsettings2.yaml}[yaml-TCB]{\texttt{bibsettings2.yaml}}{lst:bibsettings2}

	 Upon running the command
	 \begin{commandshell}
latexindent.pl bib2.bib -l bibsettings1.yaml,bibsettings2.yaml -o=+-mod2 
         \end{commandshell}
	 we receive the \emph{desired} output in \cref{lst:bib2-mod2}.

	 \cmhlistingsfromfile{demonstrations/bib2-mod2.bib}{\texttt{bib2-mod2.bib}}{lst:bib2-mod2}

	 With reference to \cref{lst:bibsettings2} we note that the \texttt{delimiterRegEx} has
	 been adjusted so that \texttt{=} symbols are used as the delimiter, but only when they
	 are \emph{not preceeded} by either \texttt{v} or \texttt{spfreload}.
 \end{example}
