Regexp::Common::Markdown - Markdown Common Regular Expressions
use Regexp::Common qw( Markdown ); while( <> ) { my $pos = pos( $_ ); /\G$RE{Markdown}{Header}/gmc and print "Found a header at pos $pos\n"; /\G$RE{Markdown}{Bold}/gmc and print "Found bold text at pos $pos\n"; }
v0.1.4
This module provides Markdown regular expressions as set out by its original author John Gruber
There are different types of patterns: vanilla and extended. To get the extended regular expressions, use the -extended switch.
-extended
You can use each regular expression by using their respective names: Bold, Blockquote, CodeBlock, CodeLine, CodeSpan, Em, HtmlOpen, HtmlClose, HtmlEmpty, Header, HeaderLine, Image, ImageRef, Line, Link, LinkAuto, LinkDefinition, LinkRef, List
Almost all of the regular expressions use named capture. See "%+" in perlvar for more information on named capture.
For example:
if( $text =~ /$RE{Markdown}{LinkAuto}/ ) { print( "Found https url \"$+{link_https}\"\n" ) if( $+{link_https} ); print( "Found file url \"$+{link_file}\"\n" ) if( $+{link_file} ); print( "Found ftp url \"$+{link_ftp}\"\n" ) if( $+{link_ftp} ); print( "Found e-mail address \"$+{link_mailto}\"\n" ) if( $+{link_mailto} ); print( "Found Found phone number \"$+{link_tel}\"\n" ) if( $+{link_tel} ); my $url = URI->new( $+{link_https} ); }
As a general rule, Markdown rule requires that the text being parsed be de-tabbed, i.e. with its tabs converted into 4 spaces. Those regular expressions reflect this principle.
$RE{Markdown}
This returns a pattern that recognises any of the supported vanilla Markdown formatting. If you pass the -extended parameter, some will be added and some of those regular expressions will be replaced by their extended ones, such as ExtAbbr, ExtCodeBlock, ExtLink, ExtAttributes
$RE{Markdown}{Blockquote}
> foo > > > bar > > foo
You can see example of this regular expression along with test units here: https://regex101.com/r/TdKq0K/1/tests
The capture names are:
The entire capture of the blockquote.
The inner content of the blockquote.
You can see also Markdown::Parser::Blockquote
$RE{Markdown}{Bold}
**This is a text in bold.** __And so is this.__
You can see example of this regular expression along with test units here: https://regex101.com/r/Jp2Kos/2/tests
The entire capture of the text in bold including the enclosing marker, which can be either ** or __
**
__
The text within the markers.
The marker type used to highlight the text. This can be either ** or __
You can see also Markdown::Parser::Bold
$RE{Markdown}{CodeBlock}
``` Some text Indented code block sample code ```
You can see example of this regular expression along with test units here: https://regex101.com/r/M6W99K/1/tests
The entire capture of the code block, including the enclosing markers, such as ```
```
The content of the code enclosed within the 2 markers.
The enclosing marker used to mark the code. Typically ```.
The possible trailing new lines. This is used to detect if any were captured in order to put them back in the parsed text for the next markdown, since the last new lines of a markdown are alos the first new lines of the next ones and new lines are used to delimit markdowns.
You can see also Markdown::Parser::Code
$RE{Markdown}{CodeLine}
the lines in this block all contain trailing spaces
You can see example of this regular expression along with test units here: https://regex101.com/r/toEboU/1/tests
This contains the data that follows the code block.
The entire capture of the code lines.
The content of the code.
This contains the leading spaces used to mark the code as code.
$RE{Markdown}{CodeSpan}
This is some `inline code`
You can see example of this regular expression along with test units here: https://regex101.com/r/C2Vl9M/1/tests
Contains the marker that delimit the inline code. The delimiter is `
`
$RE{Markdown}{Em}
This routine parameter is _test_
You can see example of this regular expression along with test units here: https://regex101.com/r/eDb6RN/2/tests
You can see also Markdown::Parser::Emphasis
$RE{Markdown}{Header}
### This is a H3 Header ### And so is this one ###
You can see example of this regular expression along with test units here: https://regex101.com/r/9uQwBk/2/tests
The text that is enclosed in the header marker.
This contains all the dashes that precedes the text. The number of dash indicates the level of the header. Thus, you could do something like this:
length( $+{header_level} );
You can see also Markdown::Parser::Header
$RE{Markdown}{HeaderLine}
This is an H1 header ==================== And this is a H2 -----------
You can see example of this regular expression along with test units here: https://regex101.com/r/sQLEqz/2/tests
This contains the marker line used to mark the line above as header.
A line using = is a header of level 1, while a line using - is a header of level 2.
=
-
$RE{Markdown}{Html}
<div> foo </div>
You can see example of this regular expression along with test units here: https://regex101.com/r/SH8ki3/1/tests
The entire capture of the html block.
If this html block is a comment, this will contain the data within the comment.
The inner content between the opning and closing tag. This could be more html block or some text.
This capture will not be available obviously for html tags that are "empty" by nature, such as <hr />
<hr /
The attributes of the opening tag, if any. For example:
<div title="Start" class="center large" id="extra_stuff"> <span title="Brand name">MyWorld</span> </div>
Here, the attributes will be:
title="Start" class="center large" id="extra_stuff"
The closing tag, including enclosing brackets.
This contains the name of the first html tag encountered, i.e. the one that starts the html block. For example:
<div> <span title="Brand name">MyWorld</span> </div>
Here the tag name will be div
div
You can see also Markdown::Parser::HTML
$RE{Markdown}{Image}
![Alt text](/path/to/img.jpg)
or
![Alt text](/path/to/img.jpg "Optional title")
or, with reference:
![alt text][foo]
You can see example of this regular expression along with test units here: https://regex101.com/r/z0yH2F/4/tests
The entire capture of the markdown, such as:
The alternative tet to be displayed for this image. This is mandatory as per markdown, so it is guaranteed to be available.
If the image, is an image reference, this will contain the reference id. When an image id is provided, there is no url and no title, because the image reference provides those information.
This is the title of the image, which may not exist, since it is optional in markdown. The title is surrounded by single or double quote that are captured in img_title_container
This is the url of the image.
You can see also Markdown::Parser::Image
$RE{Markdown}{Line}
---
- - -
***
* * *
___
_ _ _
You can see example of this regular expression along with test units here: https://regex101.com/r/Vlew4X/2
The entire capture of the horizontal line.
This contains the marker used to set the line. Valid markers are *, -, or _
*
_
See also Markdown original author reference for horizontal line
You can see also Markdown::Parser::Line
$RE{Markdown}{LineBreak}
Mignonne, allons voir si la rose Qui ce matin avait déclose Sa robe de pourpre au soleil, A point perdu cette vesprée, Les plis de sa robe pourprée, Et son teint au vôtre pareil.
To ensure arbitrary line breaks, each line ends with 2 spaces and 1 line break. This should become:
Mignonne, allons voir si la rose<br /> Qui ce matin avait déclose<br /> Sa robe de pourpre au soleil,<br /> A point perdu cette vesprée,<br /> Les plis de sa robe pourprée,<br /> Et son teint au vôtre pareil.
P.S.: If you're wondering, this is an extract from Ronsard.
You can see example of this regular expression along with test units here: https://regex101.com/r/6VG46H/1/
There is only one capture name: br_all. This is basically used like this:
br_all
if( $text =~ /\G$RE{Markdown}{LineBreak}/ ) { print( "Found a line break\n" ); }
Or
$text =~ s/$RE{Markdown}{LineBreak}/<br \/>\n/gs;
You can see also Markdown::Parser::NewLine
The capture name is:
The entire capture of the line break.
$RE{Markdown}{Link}
[Inline link](https://www.example.com "title")
[Inline link](/some/path "title")
or, without title
[Inline link](/some/path)
or with a reference id:
[reference link][refid] [refid]: /path/to/something (Title)
or, using the link text as the id for the reference:
[My Example][] [My Example]: https://example.com (Great Example)
You can see example of this regular expression along with test units here: https://regex101.com/r/sGsOIv/4/tests
The entire capture of the link.
If there is a link title, this contains the single or double quote enclosing it.
The link reference id. For example here 1 is the id.
1
[Reference link 1 with parens][1]
The link text
The link title, if any.
The link url, if any
You can see also Markdown::Parser::Link
$RE{Markdown}{LinkAuto}
Supports, http, https, ftp, newsgroup, local file, e-mail address or phone numbers
<https://www.example.com>
would become:
<a href="https://www.example.com">https://www.example.com</a>
An e-mail such as:
<!#$%&'*+-/=?^_`.{|}~@example.com>
<a href="mailto:!#$%&'*+-/=?^_`.{|}~@example.com>!#$%&'*+-/=?^_`.{|}~@example.com</a>
Other possible and valid e-mail addresses:
<"abc@def"@example.com> <jsmith@[192.0.2.1]>
A file link:
<file:///Volume/User/john/Document/form.rtf>
A newsgroup link:
<news:alt.fr.perl>
A ftp uri:
<ftp://ftp.example.com/plop/>
Phone numbers:
<+81-90-1234-5678> <tel:+81-90-1234-5678>
You can see example of this regular expression along with test units here: https://regex101.com/r/bAUu1E/3/tests
A local file url, such as: ile:///Volume/User/john/Document/form.rtf
ile:///Volume/User/john/Document/form.rtf
Contains an ftp url
Contains an http url
Contains an https url
An e-mail address with or without the mailto: prefix.
mailto:
A newsgroup link url, such as news:alt.fr.perl
news:alt.fr.perl
Contains a telephone url according to the rfc 3966
Contains the link uri, which contains one of link_file, link_ftp, link_http, link_https, link_mailto, link_news or link_tel
$RE{Markdown}{LinkDefinition}
[1]: /url/ "Title" [refid]: /path/to/something (Title)
You can see example of this regular expression along with test units here: https://regex101.com/r/edg2F7/2/tests
The link id
The link title
The character used to enclose the title, if any. This is either " or '
"
'
The link url
You can see also Markdown::Parser::LinkDefinition
$RE{Markdown}{LinkRef}
Example:
Foo [bar] [1]. Foo [bar][1]. Foo [bar] [1]. [Foo][] [1]: /url/ "Title" [Foo]: https://www.example.com
You can see example of this regular expression along with test units here: https://regex101.com/r/QmyfnH/1/tests
See also the reference on links by Markdown original author
$RE{Markdown}{List}
For example, an unordered list:
* asterisk 1 * asterisk 2 * asterisk 3
or, an ordered list:
1. One item 1. Second item 1. Third item
You can see example of this regular expression along with test units here: https://regex101.com/r/RfhRVg/4
The data that follows the list.
The entire capture of the markdown.
The content of the list.
Contains the first list marker possible preceded by some space. A list marker is *, or +, or - or a digit with a dot such as 1.
+
1.
Contains the list marker such as *, or +, or - or a digit with a dot such as 1.
This is included in the list_prefix named capture.
Sale as list_type_any, but matches the following item if any. If there is no matching item, then an end of string is expected.
Contains a digit followed by a dot if the list is an ordered one.
Same as list_type_ordered, but for the following list item, if any.
Contains the marker of a minus - value if the list marker uses a minus sign.
Same as list_type_unordered_minus, but for the following list item, if any.
Contains the marker of a plus + value if the list marker uses a plus sign.
Same as list_type_unordered_plus, but for the following list item, if any.
Contains the marker of a star * value if the list marker uses a star.
Same as list_type_unordered_star, but for the following list item, if any.
You can see also Markdown::Parser::List
$RE{Markdown}{ListFirstLevel}
This regular expression is used for top level list, as opposed to the nth level pattern that is used for sub list. Both will match lists within list, but the processing under markdown is different whether the list is a top level one or an sub one.
$RE{Markdown}{ListNthLevel}
Regular expression to process list within list.
$RE{Markdown}{ListItem}
You can see example of this regular expression along with test units here: https://regex101.com/r/bulBCP/1/tests
Contains the data contained in this list item
The optional leding line breaks
The optional leading spaces or tabs. This is used to check that following items belong to the same list level
This contains the list type marker, which can be *, +, - or a digit with a dot such as 1.
This contains a true value if the list marker contains a digit followed by a dot, such as 1.
This contains a true value if the list marker is a minus sign, i.e. -
This contains a true value if the list marker is a plus sign, i.e. +
This contains a true value if the list marker is a star, i.e. *
You can see also Markdown::Parser::ListItem
$RE{Markdown}{Paragraph}
The quick brown fox jumps over the lazy dog Lorem Ipsum > Why am I matching? 1. Nonononono! * Aaaagh! # Stahhhp!
This regular expression would capture the whole block up until "Lorem Ipsum", but will be careful not to catch other markdown element after that. Thus, anything after "Lorem Ipsum" would not be caught because this is a blockquote.
You can see example of this regular expression along with test units here: https://regex101.com/r/0B3gR4/3
The entire capture of the paragraph.
Content of the paragraph
Any leading space (up to 3)
You can see also Markdown::Parser::Paragraph
$RE{Markdown}{ExtAbbr}
Some discussion about HTML, SGML and HTML4. *[HTML4]: Hyper Text Markup Language version 4 *[HTML]: Hyper Text Markup Language *[SGML]: Standard Generalized Markup Language
You can see example of this regular expression along with test units here: https://regex101.com/r/ztM2Pw/2/tests
The entire capture of the abbreviation.
Contains the abbreviation. For example HTML
HTML
Contains the abbreviation value. For example Hyper Text Markup Language
Hyper Text Markup Language
You can see also Markdown::Parser::Abbr
$RE{Markdown}{ExtAttributes}
For example, an header with attribute .cl.class#id7
.cl.class#id7
### Header {.cl.class#id7 }
$RE{Markdown}{ExtCodeBlock}
This is the same as conventional blocks with backticks, except the extended version uses tilde characters.
~~~ <div> ~~~
You can see example of this regular expression along with test units here: https://regex101.com/r/Y9lPAz/2/tests
The entire capture of the code.
The class and/or id attributes for this code. This is something like:
`````` .html {#codeid} </div> ``````
Here, code_class would contain #codeid
#codeid
The class of code. For example:
``````html {#codeid} </div> ``````
Here the code class would be html
html
The code data enclosed within the code markers (backticks or tilde)
Contains the code delimiter, which is either a series of backticks ` or tilde ~
~
$RE{Markdown}{ExtFootnote}
This looks like this:
[^1]: Content for fifth footnote. [^2]: Content for sixth footnote spaning on three lines, with some span-level markup like _emphasis_, a [link][].
A reference to those footnotes could be:
Some paragraph with a footnote[^1], and another[^2].
The footnote_id reference can be anything as long as it is unique.
You can see also Markdown::Parser::Footnote
For consistency with links, footnotes can be added inline, like this:
I met Jack [^jack](Co-founder of Angels, Inc) at the meet-up.
Inline notes will work even without the identifier. For example:
I met Jack [^](Co-founder of Angels, Inc) at the meet-up.
However, in compliance with pandoc footnotes style, inline footnotes can also be added like this:
Here is an inline note.^[Inlines notes are easier to write, since you don't have to pick an identifier and move down to type the note.]
You can see example of this regular expression along with test units here: https://regex101.com/r/WuB1FR/2/
The entire capture of the footnote.
The footnote id which must be unique and will be referenced in text.
The footnote text
$RE{Markdown}{ExtFootnoteReference}
This regular expression matches 3 types of footnote references:
An id is specified referring to a footnote that provide details.
Here's a simple footnote,[^1] [^1]: This is the first footnote.
Inline footnotes without any id, i.e. auto-generated id. For example:
See pandoc manual for more information
You can see example of this regular expression along with test units here: https://regex101.com/r/3eO7rJ/1/
The entire capture of the footnote reference.
The footnote id which must be unique and must match a footnote declared anywhere in the document and not necessarily before. For example:
1 here is the id fo the footnote.
If it is not provided, then an id will be auto-generated, but a footnote text is then required.
The footnote text is optional if an id is provided. If an id is not provided, the fotnote text is guaranteed to have some value.
You can see also Markdown::Parser::FootnoteReference
$RE{Markdown}{ExtHeader}
This extends regular header with attributes.
You can see example of this regular expression along with test units here: https://regex101.com/r/GyzbR2/1
Contains the extended attribute set. For example:
{.class#id}
$RE{Markdown}{ExtHeaderLine}
Same as header line, but with attributes.
Header {#id5.cl.class} ======
You can see example of this regular expression along with test units here: https://regex101.com/r/berfAR/2/tests
$RE{Markdown}{ExtImage}
Same as regular image, but with attributes.
This is an ![inline image](/img "title"){.class #inline-img}.
You can see example of this regular expression along with test units here: https://regex101.com/r/xetHV1/2
$RE{Markdown}{ExtLink}
Same as regular links, but with attributes.
This is an [inline link](/url "title"){.class #inline-link}.
You can see example of this regular expression along with test units here: https://regex101.com/r/7mLssJ/2
$RE{Markdown}{ExtLinkDefinition}
Same as regular link definition, but with attributes
[refid]: /path/to/something (Title) { .class #ref data-key=val }
You can see example of this regular expression along with test units here: https://regex101.com/r/hVfXCe/2/
$RE{Markdown}{ExtSubscript}
2~10~ is 1024.
would set 10 as a subscript by the software using this regular expression.
10
You can see example of this regular expression along with test units here: https://regex101.com/r/gF6wVe/1/tests
The entire capture of the subscript.
Contains the text of the subscript
See also: Markdown::Parser::Subscript, Pandoc manual
$RE{Markdown}{ExtSuperscript}
2^10^ is 1024.
would set 10 in superscript by the software using this regular expression.
You can see example of this regular expression along with test units here: https://regex101.com/r/yAcNcX/1
The entire capture of the superscript.
Contains the text of the superscript
See also: Markdown::Parser::Superscript, Pandoc manual, https://facelessuser.github.io/pymdown-extensions/extensions/caret/
$RE{Markdown}{ExtTable}
You can see example of this regular expression along with test units here: https://regex101.com/r/01XCqB/9/tests
The entire capture of the table.
Contains the data that follows the table.
Contains the table caption if set. A table caption, in markdown can be position before or after the table.
If you use "%-" in perlvar then $-{table_caption}-[0]> will give you the table caption if it was set at the top of the table, and $-{table_caption}-[1]> will give you the table caption if it was set at the bottom of the table.
$-{table_caption}-
Contains the entire header rows
Contains the first row of the header. This is contained within the capture name table_headers
Contains the second row, if any, of the header. This is contained within the capture name table_headers
A second is optional and there can be only two rows in the headers as per standards.
Contain the separator line between the table header and the table body.
Contains the table body rows
Table format is taken from David E. Wheeler RFC
You can see also Markdown::Parser::Table
Regexp::Common for a general description of how to use this interface.
Markdown::Parser for a Markdown parser using this module.
Feel free to reach out to the author for possible corrections, improvements, or suggestions.
Jacques Deguest <jack@deguest.jp>
Credits to Michel Fortin and John Gruber for their test units.
Credits to Firas Dib for his online regular expression test tool.
Copyright (c) 2020 DEGUEST Pte. Ltd.
You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.
To install Regexp::Common::Markdown, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Regexp::Common::Markdown
CPAN shell
perl -MCPAN -e shell install Regexp::Common::Markdown
For more information on module installation, please visit the detailed CPAN module installation guide.