9. Fine tuning
latexindent.pl
operates by looking for the code blocks detailed in Table 2. The fine tuning of the details of such code blocks is controlled by the fineTuning
field, detailed in Listing 583.
This field is for those that would like to peek under the bonnet/hood and make some fine tuning to latexindent.pl
’s operating.
Warning
Making changes to the fine tuning may have significant consequences for your indentation scheme, proceed with caution!
629fineTuning:
630 environments:
631 name: [a-zA-Z@\*0-9_\\]+
632 ifElseFi:
633 name: (?!@?if[a-zA-Z@]*?\{)@?if[a-zA-Z@]*?
634 commands:
635 name: [+a-zA-Z@\*0-9_\:]+?
636 items:
637 canBeFollowedBy: (?:\[[^]]*?\])|(?:<[^>]*?>)
638 keyEqualsValuesBracesBrackets:
639 name: [a-zA-Z@\*0-9_\/.:\#-]+[a-zA-Z@\*0-9_\/.\h\{\}:\#-]*?
640 follow: (?:(?<!\\)\{)|,|(?:(?<!\\)\[)
641 namedGroupingBracesBrackets:
642 name: [0-9\.a-zA-Z@\*><]+?
643 follow: \h|\R|\{|\[|\$|\)|\(
644 UnNamedGroupingBracesBrackets:
645 follow: \{|\[|,|&|\)|\(|\$
646 arguments:
647 before: (?:#\d\h*;?,?\/?)+|\<.*?\>
648 between: _|\^|\*
649 trailingComments:
650 notPreceededBy: (?<!\\)
651 afterComment: .*?
652 modifyLineBreaks:
653 doubleBackSlash: \\\\(?:\h*\[\h*\d+\h*[a-zA-Z]+\h*\])?
654 comma: ','
655 betterFullStop: |-
656 (?x) # ignore spaces in the below
657 (?: #
658 \.\) # .)
659 (?!\h*[a-z]) # not *followed by* a-z
660 ) #
661 | # OR
662 (?: #
663 (?<! # not *preceded by*
664 (?: #
665 (?:[eE]\.[gG]) # e.g OR E.g OR e.G OR E.G
666 | #
667 (?:[iI]\.[eE]) # i.e OR I.e OR i.E OR I.E
668 | #
669 (?:etc) # etc
670 | #
671 (?:[wW]\.[rR]\.[tT]) # w.r.t OR W.r.t OR w.R.t OR w.r.T OR W.R.t OR W.r.T OR w.R.T OR W.R.T
672 ) #
673 ) #
674 ) #
675 \. # .
676 (?! # not *followed by*
677 (?: #
678 [a-zA-Z0-9-~,] #
679 | #
680 \), # ),
681 | #
682 \)\. # ).
683 ) #
684 ) #
The fields given in Listing 583 are all regular expressions. This manual is not intended to be a tutorial on regular expressions; you might like to read, for example, (Friedl, n.d.) for a detailed covering of the topic.
We make the following comments with reference to Listing 583:
the
environments:name
field details that the name of an environment can contain:a-z
lower case lettersA-Z
upper case letters@
the@
’letter’\*
stars0-9
numbers_
underscores\
backslashes
The
+
at the end means at least one of the above characters.the
ifElseFi:name
field:@?
means that it can possibly begin with@
followed by
if
followed by 0 or more characters from
a-z
,A-Z
and@
the
?
the end means non-greedy, which means ‘stop the match as soon as possible’
the
keyEqualsValuesBracesBrackets
contains some interesting syntax:|
means ‘or’(?:(?<!\\)\{)
the(?:...)
uses a non-capturing group – you don’t necessarily need to worry about what this means, but just know that for thefineTuning
feature you should only ever use non-capturing groups, and not capturing groups, which are simply(...)
(?<!\\)\{)
means a{
but it can not be immediately preceded by a\
in the
arguments:before
field\d\h*
means a digit (i.e. a number), followed by 0 or more horizontal spaces;?,?
means possibly a semi-colon, and possibly a comma\<.*?\>
is designed for ’beamer’-type commands; the.*?
means anything in between<...>
the
modifyLineBreaks
field refers to fine tuning settings detailed in Section 6. In particular:betterFullStop
is in relation to the one sentence per line routine, detailed in Section 6.2doubleBackSlash
is in relation to theDBSStartsOnOwnLine
andDBSFinishesWithLineBreak
polyswitches surrounding double backslashes, see Section 6.3.2comma
is in relation to theCommaStartsOnOwnLine
andCommaFinishesWithLineBreak
polyswitches surrounding commas in optional and mandatory arguments; see Table 3
It is not obvious from Listing 583, but each of the follow
, before
and between
fields allow trailing comments, line breaks, and horizontal spaces between each character.
Warning
For the fineTuning
feature you should only ever use non-capturing groups, such as (?:...)
and not capturing groups, which are (...)
As a demonstration, consider the file given in Listing 584, together with its default output using the command
latexindent.pl finetuning1.tex
is given in Listing 585.
\mycommand{
\rule{G -> +H[-G]CL}
\rule{H -> -G[+H]CL}
\rule{g -> +h[-g]cL}
\rule{h -> -g[+h]cL}
}
\mycommand{
\rule{G -> +H[-G]CL}
\rule{H -> -G[+H]CL}
\rule{g -> +h[-g]cL}
\rule{h -> -g[+h]cL}
}
It’s clear from Listing 585 that the indentation scheme has not worked as expected. We can fine tune the indentation scheme by employing the settings given in Listing 587 and running the command
latexindent.pl finetuning1.tex -l=fine-tuning1.yaml
and the associated (desired) output is given in Listing 586.
\mycommand{
\rule{G -> +H[-G]CL}
\rule{H -> -G[+H]CL}
\rule{g -> +h[-g]cL}
\rule{h -> -g[+h]cL}
}
fineTuning:
arguments:
between: '_|\^|\*|\->|\-|\+|h|H|g|G'
Let’s have another demonstration; consider the file given in Listing 588, together with its default output using the command
latexindent.pl finetuning2.tex
is given in Listing 589.
@misc{ wikilatex,
author = "{Wikipedia contributors}",
title = "LaTeX --- {Wikipedia}{,}",
note = "[Online; accessed 3-March-2020]"
}
@misc{ wikilatex,
author = "{Wikipedia contributors}",
title = "LaTeX --- {Wikipedia}{,}",
note = "[Online; accessed 3-March-2020]"
}
It’s clear from Listing 589 that the indentation scheme has not worked as expected. We can fine tune the indentation scheme by employing the settings given in Listing 591 and running the command
latexindent.pl finetuning2.tex -l=fine-tuning2.yaml
and the associated (desired) output is given in Listing 590.
@misc{ wikilatex,
author = "{Wikipedia contributors}",
title = "LaTeX --- {Wikipedia}{,}",
note = "[Online; accessed 3-March-2020]"
}
fineTuning:
NamedGroupingBracesBrackets:
follow: '\h|\R|\{|\[|\$|\)|\(|"'
UnNamedGroupingBracesBrackets:
follow: '\{|\[|,|&|\)|\(|\$|"'
arguments:
between: '_|\^|\*|---'
In particular, note that the settings in Listing 591 specify that NamedGroupingBracesBrackets
and UnNamedGroupingBracesBrackets
can follow "
and that we allow ---
between arguments.
You can tweak the fineTuning
using the -y
switch, but to be sure to use quotes appropriately. For example, starting with the code in Listing 592 and running the following command
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
gives the output shown in Listing 593.
We go; you see: this sentence \cite{tex:stackexchange} finishes here.
We go;
you see:
this sentence \cite{tex:stackexchange} finishes here.
We can tweak the fineTuning
for how trailing comments are classified. For motivation, let’s consider the code given in Listing 594
some before text
\href{Handbook%20for%30Spoken%40document.pdf}{my document}
some after text
We will compare the settings given in Listing 595 and Listing 596.
modifyLineBreaks:
textWrapOptions:
columns: -1
blocksEndBefore:
verbatim: 0
blocksFollow:
verbatim: 0
removeTrailingWhitespace:
beforeProcessing: 1
fineTuning:
trailingComments:
notPreceededBy: '(?:(?<!Handbook)(?<!for)(?<!Spoken))'
modifyLineBreaks:
textWrapOptions:
columns: -1
blocksEndBefore:
verbatim: 0
blocksFollow:
verbatim: 0
removeTrailingWhitespace:
beforeProcessing: 1
Upon running the following commands
latexindent.pl -m finetuning4.tex -o=+-mod1 -l=href1
latexindent.pl -m finetuning4.tex -o=+-mod2 -l=href2
we receive the respective output in Listing 597 and Listing 598.
some before text \href{Handbooksome after text%20for%30Spoken%40document.pdf}{my document}
some before text \href{Handbook%20for%30Spoken%40document.pdf}{my document} some after text
We note that in:
Listing 597 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!
Listing 598 has fine-tuned the trailing comment matching, and says that % cannot be immediately preceded 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.
Another approach to this situation, which does not use fineTuning
, is to use noIndentBlock
which we discussed in Listing 60; using the settings in Listing 599 and running the command
latexindent.pl -m finetuning4.tex -o=+-mod3 -l=href3
then we receive the same output given in Listing 598.
modifyLineBreaks:
textWrapOptions:
columns: -1
blocksEndBefore:
verbatim: 0
blocksFollow:
verbatim: 0
noIndentBlock:
href:
begin: '\\href\{[^}]*?\}\{'
body: '[^}]*?'
end: '\}'
With reference to the body
field in Listing 599, we note that the 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.
We can use the fineTuning
field to assist in the formatting of bibliography files.
Starting with the file in Listing 600 and running the command
latexindent.pl bib1.tex -o=+-mod1
gives the output in Listing 601.
@online{paulo,
title="arararule,indent.yaml",
author="PauloCereda",
date={2013-05-23},
urldate={2021-03-19},
keywords={contributor},}
@online{paulo,
title="arararule,indent.yaml",
author="PauloCereda",
date={2013-05-23},
urldate={2021-03-19},
keywords={contributor},}
Let’s assume that we would like to format the output so as to align the =
symbols. Using the settings in Listing 603 and running the command
latexindent.pl bib1.bib -l bibsettings1.yaml -o=+-mod2
gives the output in Listing 602.
@online{paulo,
title = "arararule,indent.yaml",
author = "PauloCereda",
date = {2013-05-23},
urldate = {2021-03-19},
keywords = {contributor},}
lookForAlignDelims:
online:
delimiterRegEx: '(=)'
fineTuning:
keyEqualsValuesBracesBrackets:
follow: '(?:(?<!\\)\{)|(?:(?<!\\)\[)'
UnNamedGroupingBracesBrackets:
follow: '\{|\[|,|&|\)|\(|\$|='
Some notes about Listing 603:
we have populated the
lookForAlignDelims
field with theonline
command, and have used thedelimiterRegEx
, discussed in Section 5.5.4;we have tweaked the
keyEqualsValuesBracesBrackets
code block so that it will not be found following a comma; this means that, in contrast to the default behaviour, the lines such asdate={2013-05-23},
will not be treated as key-equals-value braces;the adjustment to
keyEqualsValuesBracesBrackets
necessitates the associated change to theUnNamedGroupingBracesBrackets
field so that they will be searched for following=
symbols.
We can build upon Listing 603 for slightly more complicated bibliography files.
Starting with the file in Listing 604 and running the command
latexindent.pl bib2.bib -l bibsettings1.yaml -o=+-mod1
gives the output in Listing 605.
@online{cmh:videodemo,
title="Videodemonstrationofpl.latexindentonyoutube",
url="https://www.youtube.com/watch?v=wo38aaH2F4E&spfreload=10",
urldate={2017-02-21},
}
@online{cmh:videodemo,
title = "Videodemonstrationofpl.latexindentonyoutube",
url = "https://www.youtube.com/watch?v = wo38aaH2F4E&spfreload = 10",
urldate = {2017-02-21},
}
The output in Listing 605 is not ideal, as the =
symbol within the url field has been incorrectly used as an alignment delimiter.
We address this by tweaking the delimiterRegEx
field in Listing 606.
lookForAlignDelims:
online:
delimiterRegEx: '(?<!v)(?<!spfreload)(=)'
Upon running the command
latexindent.pl bib2.bib -l bibsettings1.yaml,bibsettings2.yaml -o=+-mod2
we receive the desired output in Listing 607.
@online{cmh:videodemo,
title = "Videodemonstrationofpl.latexindentonyoutube",
url = "https://www.youtube.com/watch?v=wo38aaH2F4E&spfreload=10",
urldate = {2017-02-21},
}
With reference to Listing 606 we note that the delimiterRegEx
has been adjusted so that =
symbols are used as the delimiter, but only when they are not preceded by either v
or spfreload
.
We can use the fineTuning
settings to tweak how latexindent.pl
finds trailing comments. We begin with the file in Listing 608
\chapter{chapter text} % 123
chapter text
\section{section text} % 456
section text
% end
% end
Using the settings in Listing 610 and running the command
latexindent.pl finetuning5.tex -l=fine-tuning3.yaml
gives the output in Listing 609.
\chapter{chapter text} % 123
chapter text
\section{section text} % 456
section text
% end
% end
fineTuning:
trailingComments:
notPreceededBy: (?<!\\)
afterComment: (?!(?:\hend)).*?
specialBeginEnd:
customSection:
begin: \\(?:section|chapter)
end: \%\h+end
specialBeforeCommand: 1
The settings in Listing 610 detail that trailing comments can not be followed by a single space, and then the text ‘end’. This means that the specialBeginEnd
routine will be able to find the pattern % end
as the end
part. The trailing comments 123
and 456
are still treated as trailing comments.
Friedl, Jeffrey E. F. n.d. Mastering Regular Expressions.