daamien@411119b removes `type="text/css"` from both `<style>` and `<rel="stylesheet">` elements in all templates. However, Amazon’s kindlegen software relies on this attribute on `<link>` elements when detecting stylesheets to include.
The `system` Lua module provides utility functions to interact with the
operating- and file system. E.g.
print(pandoc.system.get_current_directory())
or
pandoc.system.with_temporary_directory('tikz', function (dir)
-- write and compile a TikZ file with pdflatex
end)
This file has been removed in 3.8.0: 29b0e86089
Add a note in the changelog that users will need to update reveal.js to at least 3.8.0
for their presentations generated with this version of pandoc to work correctly.
The previous built-in reference doc had only title and content
layouts. Add in a section-header slide and a two-content slide, so
users can more easily modify it to build their own templates.
Golden files needed to be regenerated. Checked on MS PowerPoint 2013.
Improve the workaround for #1658, adapting a solution by @u-fischer in
<https://github.com/latex3/latex2e/issues/131> that works whether or not
the `indent` variable is enabled.
Remove `subparagraph` variable in LaTeX template. The default is now
to use run-in style for level 4 and 5 headings (`\paragraph` and `\subparagraph`).
To get the previous default behavior (where these were formatted as blocks,
like `\subsubsection`), set the `block-headings` variable.
An example is given in the manual of reformatting the appearance of headings
more thoroughly using KOMA-Script.
Closes#5365.
* LaTeX template: Group graphics-related code
The default figure placement was added in <f3ab4bc2b9>; there does not appear to have been a reason for placing it at the end of the preamble.
* Update tests
+ LaTeX template: Improve template readability
Use `hidelinks` option for hyperref, which has the same effect as `pdfborder={0 0 0}`,
but its purpose is clearer. Use a simpler conditional for Polyglossia/Babel. Format
comments more consistently.
+ Update tests
+ Remove hyperref breaklinks option. According to the documentation, hyperref
sets this automatically as appropriate to the driver.
Closes#5345
Runs tectonic on STDIN instead of a temporary .tex file, so that it
looks in the working directory for `\include` and `\input` like the rest
of the engines.
Allows overriding the output directory without messing up the args
with `--pdf-engine-opt=--outdir --pdf-engine-opt="$DIR"`.
In pandoc 2.7 we assumed that every class with chapters would
accept `\frontmatter`, `\mainmatter`, and `\backmatter`.
This is not so (e.g. report does not). So pandoc 2.7
breaks on report class by including an unsupported command.
So we replace the book-class variable in the template with
two variables, has-chapters and has-frontmatter, and set
these intelligently in the writer.
Closes#5348.
The file `init.lua` in pandoc's data directory is run as part of
pandoc's Lua initialization process. Previously, the `pandoc` module was
loaded in `init.lua`, and the structure for marshaling was set-up after.
This allowed simple patching of element marshaling, but made using
`init.lua` more difficult:
- it encouraged mixing essential initialization with user-defined
customization;
- upstream changes to init.lua had to be merged manually;
- accidentally breaking marshaling by removing required modules was
possible;
Instead, all required modules are now loaded before calling `init.lua`.
The file can be used entirely for user customization. Patching
marshaling functions, while discouraged, is still possible via the
`debug` module.
All Lua modules bundled with pandoc, i.e., `pandoc.List`,
`pandoc.mediabag`, `pandoc.utils`, and `text` are re-exported from the
`pandoc` module. They are assigned to the fields `List`, `mediabag`,
`utils`, and `text`, respectively.
Quite a few modules were missing copyright notices.
This commit adds copyright notices everywhere via haddock module
headers. The old license boilerplate comment is redundant with this and has
been removed.
Update copyright years to 2019.
Closes#4592.
Otherwise we get an error when trying to compile code
with lua or assembler code.
To change the default dialect (currenty 5.3 for lua
and x86masm for assembler), you can use `--include-in-header`
to inject something like
\lstset{defaultdialect=[5.2]Lua}
Closes#5227.
The `\institute` command is only standard in the Beamer class.
Use a conditional to restrict this to Beamer output rather than
output an empty command. To add this information to a LaTeX
class providing an `\institute` command, use `header-includes`.
Use the [`footnotehyper`](https://ctan.org/pkg/footnotehyper/) package if available.
This is a rewrite of `footnote` that is compatible with `hyperref` and `babel-frenchb`.
This patch also addresses the incompatibility with `xcolor` noted in #4861, but the
new package has only been available since 2016, so this template still loads `xcolor`
earlier for compatibility with older distributions. Note that the `footnote` package
is part of `collection-latexrecommended` in TeX Live, so there shouldn't be any
problem loading it unconditionally as we now do if `footnotehyper` is not available.
Ensure that `\part` and `\chapter` are only numbered if `numbersections` is set. To return to the previous behaviour, use `-V numbersections -V secnumdepth=0`.
Notes on secnumdepth:
1 = Number `\section`
0 = Number `\chapter`
-1 = Number `\part`
-2 = No numbering
Incorrect types to pandoc element constructors are automatically
converted to the correct types when possible. This was already done for
most constructors, but conversions are now also done for nested
types (like lists of lists).
Simplify the approach of #5212, ensuring that `mainfont` is used as the base font for scaling and that LuaLaTeX does not display the mono font with TeX ligatures (as it does not use the `Mapping=tex-ansi` option).
With a modified version of `\defaultfontfeatures`, fontspec will continue to report scaling against the old default font in the log, but it nonetheless displays main font at the specified size. Using this rather than setting `Scale=MatchLowercase` for each family individually means that users will not lose scaling when upgrading to the new template if they were using other font options. Scaling can be disabled for an individual family by adding the option `Scale=1` to `sansfontoptions`, `monofontoptions`, etc.
Remove the `\setromanfont` command added in #4665, as this is not documented in the fontspec manual and appears to be a deprecated alias for `\setmainfont`.
For the release notes, I should also add that one can imitate the previous appearance with `-V mainfontoptions="Scale=MatchLowercase"`.
Addresses closed issues #4675, #3896, #1327.
This renders `\subtitle` using the `etoolbox` package if `\subtitle` is not already
defined by the documentclass (as it is in beamer, KOMA, memoir classes).
Based on an example from Enrico Gregorio, <https://tex.stackexchange.com/a/50186>.
Update list of LaTeX packages.
Note that `etoolbox` must be loaded outside the command definition.
Putting it inside causes an error if `\title` is placed after `\begin{document}`.
It's already loaded on LuaLaTeX/XeLaTeX in any case.
When `Scale=MatchLowercase` is set as a default font option, this scales `mainfont` against the old default, meaning that it resizes whatever is set as the main font to match the metrics of Latin Modern. This can result, for example, in a document set to 12pt appearing in 11pt or 13pt. Setting this option for individual families allows everything to scale against the main font, and permits the user to override the setting if desired. Note that it is not necessary to specify `Ligatures=TeX`, as this is already set by default for the appropriate families. See the `fontspec` manual: <https://ctan.org/pkg/fontspec>.
Those who specify font-options in metadata may need to add `Scale=MatchLowercase`, which will now only be provided if `(roman|sans|math|mono)fontoptions` aren't given explicitly.
* Use Babel for LuaTeX. There are a number of bugs in Polyglossia under LuaLaTeX with common languages, e.g. <https://github.com/reutenauer/polyglossia/issues/182>.
* Load xcolor. The `xcolor` package must be loaded before the `footnote` package, which we load to fix foonotes in tables. Closes#4861.
* Load xurl if available. This breaks URLs in more locations. Only available with TeX Live 2018 and later.
* Remove obsolete fixltx2e package
* Reindent. Use two spaces to be consistent internally and with other templates.
* Use `bookmark` if available. The `bookmark` package can sometimes correct the levels of headings where `hyperref` cannot: see <https://komascript.de/release3.26>.
* Update LaTeX tests
* Add 'landmarks' id attribute to the landmarks nav.
* Replace old default CSS removing numbers from ol.toc li
with new rules that match `nav#toc ol, nav#landmarks ol`.
* We keep the `toc` class on `ol` for backwards compatibility.
Equality of Lua objects representing pandoc AST elements is tested by
unmarshalling the objects and comparing the result in Haskell. A new
function `equals` which performs this test has been added to the
`pandoc.utils` module.
Closes: #5092
The underline style is now deprecated.
Previously `--atx-headers` would enable the single-line
style; now the single-line style is always used.
Closes#5038.
This makes it possible to iterate over all field names of an AST element
by using a generic `for` loop with `pairs`:
for field_name, field_content in pairs(element) do
…
end
Raw table fields of AST elements should be considered an implementation
detail and might change in the future. Accessing element properties
should always happen through the fields listed in the Lua filter docs.
Note that the iterator currently excludes the `t`/`tag` field.
Passing a MetaList object to the constructor `pandoc.MetaList` now
returns the passed list as a MetaList. This is consistent with the
constructor behavior when passed an (untagged) list.
Previously, the constructor used to create a new MetaList with the
passed MetaList as its only element.
Custom writers have access to the global variable `PANDOC_DOCUMENT`. The
variable contains a userdata wrapper around the full pandoc AST and
exposes two fields, `meta` and `blocks`. The field content is only
marshaled on-demand, performance of scripts not accessing the fields
remains unaffected.
Custom writers can specify an optional `Setup` function. The function
takes the full Pandoc document as input and should not return any value.
Users can use this function to configure the writer depending on the
given document's content or its metadata.
data/sample.lua: add sample use of Setup function.
The change allows to control the image format used to encode the image
produced from dot code.
Closes#4957
Introduce a new variable `hyperrefoptions` to pass to the hyperref package.
This allows us (for example) to specify `hyperrefoptions: linktoc=all` in a YAML block.
It is a bit awkward to have a title for every frame, but not for the one
that holds the table of contents. Allow users to specify a title if they
wish.
Closes#4803
After this commit use `$titleblock$` in order to get what was contained
in `$title$` before, that is a title and subtitle rendered according to
the official rST method:
http://docutils.sourceforge.net/docs/user/rst/quickstart.html#document-title-subtitle. from
With this commit, the `$title$` and `$subtitle$` metadata are available and they
simply carry the metadata values. This opens up more possibilities in templates.
New variable with same name as comparable variable in (proposed) reveal.js template, so that background images can indicated for both presentation formats with one variable.
Removed `--latexmathml`, `--gladtex`, `--mimetex`, `--jsmath`, `-m`,
`--asciimathml` options.
Removed `JsMath`, `LaTeXMathML`, and `GladTeX` constructors from
`Text.Pandoc.Options.HTMLMathMethod` [API change].
Removed unneeded data file LaTeXMathML.js and updated tests.
Bumped version to 2.2.
This file wasn't used in the production of documents. It's supposed to
be a thumbnail of the current document, and we can't actually produce
that ourselves. It turns out that the file contains a nonfree ICC
color calibration file, so the best thing to do would be to remove it
altogether.
Fixes: #4588
Previously this looked in the filesystem, even if pandoc
was compiled with `embed_data_files` (and sometimes it looked
in a nonexistent build directory). Now the bash completion
script just includes a hard-coded list of data file names.
See #4549.
* LaTeX template: Use `pgfpages` package; this is needed for notes on second screen in beamer
* LaTeX template: Add `beameroption` variable in template
The resulting PDF can be verified using the Apache PDFBox preflight app.
```
$ java -jar preflight-app-2.0.8.jar test.pdf
The file test.pdf is a valid PDF/A-1b file
```
Instructions on how to install the ICC profiles on ConTeXt standalone can be found in the wiki: <http://wiki.contextgarden.net/PDFX#ICC_profiles>.
If the ICC profiles are not available the log will contain messages like these
```
backend > profiles > profile specification 'sRGB.icc' loaded from '/usr/local/texlive/2017/texmf-dist/tex/context/colors/icc/context/colorprofiles.xml'
backend > profiles > error, couldn't locate profile 'srgb.icc'
backend > profiles > no default profile 'srgb.icc' for colorspace 'rgb'
backend > profiles > profile specification 'sRGB IEC61966-2.1' loaded from '/usr/local/texlive/2017/texmf-dist/tex/context/colors/icc/context/colorprofiles.xml'
backend > profiles > error, couldn't locate profile 'srgb.icc'
backend > profiles > invalid output intent 'sRGB IEC61966-2.1'
```
and the resulting PDF will not be valid PDF/A:
```
$ java -jar preflight-app-2.0.8.jar test.pdf
The file test.pdf is not a valid PDF/A-1b file, error(s) :
2.4.3 : Invalid Color space, The operator "g" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, The operator "G" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, /DeviceGray default for operator "TJ" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, /DeviceGray default for operator "TJ" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, The operator "g" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, The operator "G" can't be used without Color Profile on page 1
2.4.3 : Invalid Color space, /DeviceGray default for operator "TJ" can't be used without Color Profile on page 1
```
However, the PDF will still be generated and the "errors" shown in the log do not break anything.
* Provide `bidi` package's option using `\PassOptionsToPackage`. This avoid clash when `polyglossia` loads it first and then it is loaded again for XeLaTeX when `latex-dir-rtl` defined.
* Adjust test suite for LaTeX template change.
Elements with attributes got an additional `attr` accessor. Attributes
were accessible only via the `identifier`, `classes`, and `attributes`,
which was in conflict with the documentation, which indirectly states
that such elements have the an `attr` property.
Every constructor which accepts a list of blocks now also accepts a
single block element for convenience. Furthermore, strings are accepted as
shorthand for `{pandoc.Str "text"}` in constructors.
Accessing an Attr value (e.g., ` Attr().classes`) was broken; the more
common case of accessing it via an Inline or Block element was
unaffected by this.
This attribute was out-of-sync with the actual version as is mostly
irrelevant in the context Lua filters and custom writers. Use the
global `PANDOC_API_VERSION` instead.
*Pandoc*, *Meta*, and *Citation* were just plain functions and did not
set a metatable on the returned value, which made it difficult to amend
objects of these types with new behavior. They are now subtypes of
AstElement, meaning that all their objects can gain new features when a
method is added to the behavior object (e.g., `pandoc.Pandoc.behavior`).
Clearly distinguish between a type and the behavioral properties of an instance
of that type. The behavior of a type (and all its subtypes) can now be amended
by adding methods to that types `behavior` object, without exposing the type
objects internals.
E.g.:
pandoc.Inline.behavior.frob = function () print'42' end
local str = pandoc.Str'hello'
str.frob() -- outputs '42'
Extending all elements of a given type (e.g., all inline elements) was
difficult, as the table used to lookup unknown methods would be reset
every time a new element of that type was created, preventing recursive
property lookup. This is was changed in that all methods and attributes
of supertypes are now available to their subtypes.
The fields were named like the Haskell fields, not like the documented,
shorter version. The names are changed to match the documentation and
Citations are given a shared metatable to enable simple extensibility.
Fixes: #4222
The function `global_filter` was used internally to get the implicitly
defined global filter. It was of little value to end-users, but caused
unnecessary code duplication in pandoc. The function has hence been
dropped. Internally, the global filter is now received by interpreting
the global table as lua filter.
This is a Lua API change.
Each definition list item contains just a single key and the associated
value. Using `next` to get the key/value pair is more idiomatic than
iterating over the single-element table.
Instead of just "Hello, world", the document now contains
exemplars of most of the styles that have an effect on pandoc
documents.
This makes it easier to see the effect of style changes.
Closes#4175.
instead of relying on CSS. Closes#4162. HTML-based templates have had
the custom CSS for div.line-block removed. Those maintaining custom
templates will want to remove this too.
We still enclose line blocks in a div with class line-block.
The `pipe` and `read` utility functions are converted from hybrid
lua/haskell functions into full Haskell functions. This avoids the need
for intermediate `_pipe`/`_read` helper functions, which have dropped.
The file `init.lua` is used to initialize the Lua interpreter which is
used in Lua filters. This gives users the option to require libraries
which they want to use in all of their filters, and to extend default
modules.
The integration with Lua's package/module system is improved: A
pandoc-specific package searcher is prepended to the searchers in
`package.searchers`. The modules `pandoc` and `pandoc.mediabag` can now
be loaded via `require`.
This ensures that we don't use $..$ delimiters, which
gives bad results when $ is used as a currency sign.
This depends on the current dev version of reveal.js.
The `List` metatable is assigned to the tables which get passed to the
constructors `MetaBlocks`, `MetaInline`, and `MetaList`. This enables
the use of the resulting objects as lists. This is part of the changes
discussed in #4081.
Pandoc and Meta elements are now pushed by calling the respective
constructor functions of the pandoc Lua module. This makes serialization
consistent with the way blocks and inlines are pushed to lua and allows
to use List methods with the `blocks` value.
The List module is automatically loaded, but not assigned to a global
variable. It can be included in filters by calling `List = require
'List'`.
Lists of blocks, lists of inlines, and lists of classes are now given
`List` as a metatable, making working with them more convenient. E.g.,
it is now possible to concatenate lists of inlines using Lua's
concatenation operator `..` (requires at least one of the operants to
have `List` as a metatable):
function Emph (emph)
local s = {pandoc.Space(), pandoc.Str 'emphasized'}
return pandoc.Span(emph.content .. s)
end
Closes: #4081
Attribute lists are represented as associative lists in Lua. Pure
associative lists are awkward to work with. A metatable is attached to
attribute lists, allowing to access and use the associative list as if
the attributes were stored in as normal key-value pair in table.
Note that this changes the way `pairs` works on attribute lists. Instead
of producing integer keys and two-element tables, the resulting iterator
function now returns the key and value of those pairs. Use `ipairs` to
get the old behavior.
Warning: the new iteration mechanism only works if pandoc has been
compiled with Lua 5.2 or later (current default: 5.3).
The `pandoc.Attr` function is altered to allow passing attributes as
key-values in a normal table. This is more convenient than having to
construct the associative list which is used internally.
Closes#4071
* Move as much as possible to the CSS in the template.
* Ensure that all the HTML-based templates (including epub)
contain the CSS for columns.
* Columns default to 50% width unless they are given a width
attribute.
Closes#4028.
The second argument of the OrderedList constructor, which should define
the list's attributes, is made optional. Default attributes are used if
the parameter is omitted.
Make Attr values accessible through through the keys `identifier`,
`classes` and `attributes`. This is already used in other elements with
attributes and is now fixed for Link and Image.
The pipe command is wrapped in a lua function, throwing a lua error if
the command returns with an error. A wrapper is needed as Haskell
functions exposed to lua may not throw lua errors due to limitations of
hslua.
The error handling is written such that a table can be returned as an
error object in the future. This is potentially useful when finer
control is required while catching the error in lua code. Current
limitations of hslua require error objects to be strings.
* Rename --latex-engine to --pdf-engine
* In `Text.Pandoc.Options.WriterOptions`, rename `writerLaTeXEngine` to `writerPdfEngine` and `writerLaTeXArgs` to `writerPdfArgs`.
* Add support for `weasyprint` and `prince`, in addition to `wkhtmltopdf`, for PDF generation via HTML (closes#3906).
* `Text.Pandoc.PDF.html2pdf`: use stdin instead of intermediate HTML file
We now use the default.latex template for both latex and beamer.
It contains conditionals for the beamer-specific things.
`pandoc -D beamer` will return this template.
Beamer loads `xcolor` rather than `color`, and thus the `dvipsnames` option doesn't take effect. This also provides a wider range of colour selections with the `svgnames` option. Closes#3877.
...by using the `luatexja-fontspec` and `luatexja-preset` packages. Use
existing `CJKmainfont` and `CJKoptions` template variables. Add
`luatexjafontspecoptions` for `luatexja-fontspec` and `luatexjapresetoptions`
for `luatexja-preset`.
Functions with a name that corresponds to an AST element are included in
implicit pandoc filter, but both `Meta` and `Pandoc` were wrongly
ignored till now.
The structure expected is:
<div class="columns">
<div class="column" width="40%">
contents...
</div>
<div class="column" width="60%">
contents...
</div>
</div>
Support has been added for beamer and all HTML slide formats.
Closes#1710.
Note: later we could add a more elegant way to create
this structure in Markdown than to use raw HTML div elements.
This would come for free with a "native div syntax" (#168).
Or we could devise something specific to slides
Avoids an options clash when loading a package (e.g. `tufte-latex`) that uses `hyperref` settings different from those in the template (introduced in <feffd7c64a>).
* readDataFile, readDefaultDataFile, getReferenceDocx,
getReferenceODT have been removed from Shared and
moved into Class. They are now defined in terms of
PandocMonad primitives, rather than being primitve
methods of the class.
* toLang has been moved from BCP47 to Class.
* NoTranslation and CouldNotLoudTranslations have
been added to LogMessage.
* New module, Text.Pandoc.Translations, exporting
Term, Translations, readTranslations.
* New functions in Class: translateTerm, setTranslations.
Note that nothing is loaded from data files until
translateTerm is used; setTranslation just sets the
language to be used.
* Added two translation data files in data/translations.
* LaTeX reader: Support `\setmainlanguage` or `\setdefaultlanguage`
(polyglossia) and `\figurename`.
Changed markdown, rtf, and HTML-based templates accordingly.
This allows you to set `toc: true` in the metadata; this
previously produced strange results in some output formats.
Closes#2872.
For backwards compatibility, `toc` is still set to the
toc contents. But it is recommended that you update templates
to use `table-of-contents` for the toc contents and `toc`
for a boolean flag.
* New module Text.Pandoc.Readers.Vimwiki, exporting readVimwiki [API change].
* New input format `vimwiki`.
* New data file, `data/vimwiki.css`, for displaying the HTML produced by this reader and pandoc's HTML writer in the style of vimwiki's own HTML export.
This is a thin wrapper around mathjax that makes math look better
on revealjs.
See https://github.com/hakimel/reveal.js/#mathjax
We do this by setting the 'mathjax' boolean variable and
using it in the revealjs template. Also, for revealjs
and mathjax, we don't assign the usual thing to the 'math'
variable, since it's handled by mathjax config.
Closes#3743.
The Attr argument is made optional for all pandoc element constructors
which take such a parameter. The attr param is always the last argument
of the constructor functions, so the option to omit them makes it easier
to construct new pandoc elements by hand.
* LaTeX: Load `parskip` before `hyperref`.
According to `hyperref` package's `README.pdf`, page 22, `hyperref` package
should be loaded after `parskip` package.
* Adjust tests for previous change.
The implicitly defined global filter (i.e. all element filtering
functions defined in the global lua environment) is used if no filter is
returned from a lua script. This allows to just write top-level
functions in order to define a lua filter. E.g
function Emph(elem) return pandoc.Strong(elem.content) end
Attributes was written to behave much like a normal table, in order to
simplify working with it. However, all Attr containing elements were
changed to provide panflute-like accessors to Attr components, rendering
the previous approach unnecessary.
Previously the LaTeX writer created invalid LaTeX
when `--listings` was specified and a code span occured
inside emphasis or another construction.
This is because the characters `%{}\` must be escaped
in lstinline when the listinline occurs in another
command, otherwise they must not be escaped.
To deal with this, adoping Michael Kofler's suggestion,
we always wrap lstinline in a dummy command `\passthrough`,
now defined in the default template if `--listings` is
specified. This way we can consistently escape the
special characters.
Closes#1629.
A single `read` function parsing pandoc-supported formats is added to
the module. This is simpler and more convenient than the previous method
of exposing all reader functions individually.
Meta elements that are treated as lua tables (i.e. MetaList,
MetaInlines, MetaBlocks, and MetaMap), are no longer wrapped in an
additional table but simply marked via a metatable. This allows
treating those meta values just like normal tables, while still making
empty elements of those values distinguishable.
We now issue `<div class="line-block">` and include a
default definition for `line-block` in the default
templates, instead of hard-coding a `style` on the
div.
Closes#1623.
Element attributes are pushed to the stack via the `Attributes`
function. `Attributes` creates an Attr like triple, but the triple also
allows table-like access to key-value pairs.
Provide functions `pandoc.SingleQuoted`, `pandoc.DoubleQuoted`,
`pandoc.DisplayMath`, and `pandoc.InlineMath` to allow simple building
of Math and Quoted elements.
Lua string are used to represent nullary data constructors. The previous
table-based representation was based on the JSON serialization, but can
be simplified. This also matches the way those arguments are passed to
custom writers.
Instead of taking only a single argument containing the pre-packed
element contents, `Inline` constructors now take the same arguments as
the respective filter and `Custom` writer function
Closes#3547.
Macro definitions are inserted in the template when there is highlighted
code.
Limitations: background colors and underline currently not
supported.
Modified template to include a `<back>` and `<body>` section.
This should give authors more flexibility, e.g. to put
acknowledgements metadata in `<back>`. References are
automatically extracted and put into `<back>`.
