|
|
|
@ -1,8 +1,8 @@ |
|
|
|
--- |
|
|
|
title: CommonMark Spec |
|
|
|
author: John MacFarlane |
|
|
|
version: 0.28 |
|
|
|
date: '2017-08-01' |
|
|
|
version: 0.29 |
|
|
|
date: '2019-04-06' |
|
|
|
license: '[CC-BY-SA 4.0](http://creativecommons.org/licenses/by-sa/4.0/)' |
|
|
|
... |
|
|
|
|
|
|
|
@ -248,7 +248,7 @@ satisfactory replacement for a spec. |
|
|
|
|
|
|
|
Because there is no unambiguous spec, implementations have diverged |
|
|
|
considerably. As a result, users are often surprised to find that |
|
|
|
a document that renders one way on one system (say, a github wiki) |
|
|
|
a document that renders one way on one system (say, a GitHub wiki) |
|
|
|
renders differently on another (say, converting to docbook using |
|
|
|
pandoc). To make matters worse, because nothing in Markdown counts |
|
|
|
as a "syntax error," the divergence often isn't discovered right away. |
|
|
|
@ -328,8 +328,10 @@ that is not a [whitespace character]. |
|
|
|
|
|
|
|
An [ASCII punctuation character](@) |
|
|
|
is `!`, `"`, `#`, `$`, `%`, `&`, `'`, `(`, `)`, |
|
|
|
`*`, `+`, `,`, `-`, `.`, `/`, `:`, `;`, `<`, `=`, `>`, `?`, `@`, |
|
|
|
`[`, `\`, `]`, `^`, `_`, `` ` ``, `{`, `|`, `}`, or `~`. |
|
|
|
`*`, `+`, `,`, `-`, `.`, `/` (U+0021–2F), |
|
|
|
`:`, `;`, `<`, `=`, `>`, `?`, `@` (U+003A–0040), |
|
|
|
`[`, `\`, `]`, `^`, `_`, `` ` `` (U+005B–0060), |
|
|
|
`{`, `|`, `}`, or `~` (U+007B–007E). |
|
|
|
|
|
|
|
A [punctuation character](@) is an [ASCII |
|
|
|
punctuation character] or anything in |
|
|
|
@ -514,8 +516,8 @@ one block element does not affect the inline parsing of any other. |
|
|
|
## Container blocks and leaf blocks |
|
|
|
|
|
|
|
We can divide blocks into two types: |
|
|
|
[container block](@)s, |
|
|
|
which can contain other blocks, and [leaf block](@)s, |
|
|
|
[container blocks](@), |
|
|
|
which can contain other blocks, and [leaf blocks](@), |
|
|
|
which cannot. |
|
|
|
|
|
|
|
# Leaf blocks |
|
|
|
@ -527,7 +529,7 @@ Markdown document. |
|
|
|
|
|
|
|
A line consisting of 0-3 spaces of indentation, followed by a sequence |
|
|
|
of three or more matching `-`, `_`, or `*` characters, each followed |
|
|
|
optionally by any number of spaces, forms a |
|
|
|
optionally by any number of spaces or tabs, forms a |
|
|
|
[thematic break](@). |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
@ -825,7 +827,7 @@ Contents are parsed as inlines: |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Leading and trailing blanks are ignored in parsing inline content: |
|
|
|
Leading and trailing [whitespace] is ignored in parsing inline content: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
# foo |
|
|
|
@ -1024,6 +1026,20 @@ baz* |
|
|
|
baz</em></h1> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
The contents are the result of parsing the headings's raw |
|
|
|
content as inlines. The heading's raw content is formed by |
|
|
|
concatenating the lines and removing initial and final |
|
|
|
[whitespace]. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
Foo *bar |
|
|
|
baz*→ |
|
|
|
==== |
|
|
|
. |
|
|
|
<h1>Foo <em>bar |
|
|
|
baz</em></h1> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
The underlining can be any length: |
|
|
|
|
|
|
|
@ -1584,8 +1600,8 @@ begins with a code fence, indented no more than three spaces. |
|
|
|
|
|
|
|
The line with the opening code fence may optionally contain some text |
|
|
|
following the code fence; this is trimmed of leading and trailing |
|
|
|
spaces and called the [info string](@). |
|
|
|
The [info string] may not contain any backtick |
|
|
|
whitespace and called the [info string](@). If the [info string] comes |
|
|
|
after a backtick fence, it may not contain any backtick |
|
|
|
characters. (The reason for this restriction is that otherwise |
|
|
|
some inline code would be incorrectly interpreted as the |
|
|
|
beginning of a fenced code block.) |
|
|
|
@ -1870,7 +1886,7 @@ Code fences (opening and closing) cannot contain internal spaces: |
|
|
|
``` ``` |
|
|
|
aaa |
|
|
|
. |
|
|
|
<p><code></code> |
|
|
|
<p><code> </code> |
|
|
|
aaa</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
@ -1922,9 +1938,11 @@ bar |
|
|
|
|
|
|
|
|
|
|
|
An [info string] can be provided after the opening code fence. |
|
|
|
Opening and closing spaces will be stripped, and the first word, prefixed |
|
|
|
with `language-`, is used as the value for the `class` attribute of the |
|
|
|
`code` element within the enclosing `pre` element. |
|
|
|
Although this spec doesn't mandate any particular treatment of |
|
|
|
the info string, the first word is typically used to specify |
|
|
|
the language of the code block. In HTML output, the language is |
|
|
|
normally indicated by adding a class to the `code` element consisting |
|
|
|
of `language-` followed by the language name. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
```ruby |
|
|
|
@ -1973,6 +1991,18 @@ foo</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
[Info strings] for tilde code blocks can contain backticks and tildes: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
~~~ aa ``` ~~~ |
|
|
|
foo |
|
|
|
~~~ |
|
|
|
. |
|
|
|
<pre><code class="language-aa">foo |
|
|
|
</code></pre> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Closing code fences cannot have [info strings]: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
@ -1991,14 +2021,15 @@ Closing code fences cannot have [info strings]: |
|
|
|
An [HTML block](@) is a group of lines that is treated |
|
|
|
as raw HTML (and will not be escaped in HTML output). |
|
|
|
|
|
|
|
There are seven kinds of [HTML block], which can be defined |
|
|
|
by their start and end conditions. The block begins with a line that |
|
|
|
meets a [start condition](@) (after up to three spaces |
|
|
|
optional indentation). It ends with the first subsequent line that |
|
|
|
meets a matching [end condition](@), or the last line of |
|
|
|
the document or other [container block]), if no line is encountered that meets the |
|
|
|
[end condition]. If the first line meets both the [start condition] |
|
|
|
and the [end condition], the block will contain just that line. |
|
|
|
There are seven kinds of [HTML block], which can be defined by their |
|
|
|
start and end conditions. The block begins with a line that meets a |
|
|
|
[start condition](@) (after up to three spaces optional indentation). |
|
|
|
It ends with the first subsequent line that meets a matching [end |
|
|
|
condition](@), or the last line of the document, or the last line of |
|
|
|
the [container block](#container-blocks) containing the current HTML |
|
|
|
block, if no line is encountered that meets the [end condition]. If |
|
|
|
the first line meets both the [start condition] and the [end |
|
|
|
condition], the block will contain just that line. |
|
|
|
|
|
|
|
1. **Start condition:** line begins with the string `<script`, |
|
|
|
`<pre`, or `<style` (case-insensitive), followed by whitespace, |
|
|
|
@ -2029,7 +2060,7 @@ followed by one of the strings (case-insensitive) `address`, |
|
|
|
`footer`, `form`, `frame`, `frameset`, |
|
|
|
`h1`, `h2`, `h3`, `h4`, `h5`, `h6`, `head`, `header`, `hr`, |
|
|
|
`html`, `iframe`, `legend`, `li`, `link`, `main`, `menu`, `menuitem`, |
|
|
|
`meta`, `nav`, `noframes`, `ol`, `optgroup`, `option`, `p`, `param`, |
|
|
|
`nav`, `noframes`, `ol`, `optgroup`, `option`, `p`, `param`, |
|
|
|
`section`, `source`, `summary`, `table`, `tbody`, `td`, |
|
|
|
`tfoot`, `th`, `thead`, `title`, `tr`, `track`, `ul`, followed |
|
|
|
by [whitespace], the end of the line, the string `>`, or |
|
|
|
@ -2037,16 +2068,17 @@ the string `/>`.\ |
|
|
|
**End condition:** line is followed by a [blank line]. |
|
|
|
|
|
|
|
7. **Start condition:** line begins with a complete [open tag] |
|
|
|
or [closing tag] (with any [tag name] other than `script`, |
|
|
|
`style`, or `pre`) followed only by [whitespace] |
|
|
|
or the end of the line.\ |
|
|
|
(with any [tag name] other than `script`, |
|
|
|
`style`, or `pre`) or a complete [closing tag], |
|
|
|
followed only by [whitespace] or the end of the line.\ |
|
|
|
**End condition:** line is followed by a [blank line]. |
|
|
|
|
|
|
|
HTML blocks continue until they are closed by their appropriate |
|
|
|
[end condition], or the last line of the document or other [container block]. |
|
|
|
This means any HTML **within an HTML block** that might otherwise be recognised |
|
|
|
as a start condition will be ignored by the parser and passed through as-is, |
|
|
|
without changing the parser's state. |
|
|
|
[end condition], or the last line of the document or other [container |
|
|
|
block](#container-blocks). This means any HTML **within an HTML |
|
|
|
block** that might otherwise be recognised as a start condition will |
|
|
|
be ignored by the parser and passed through as-is, without changing |
|
|
|
the parser's state. |
|
|
|
|
|
|
|
For instance, `<pre>` within a HTML block started by `<table>` will not affect |
|
|
|
the parser state; as the HTML block was started in by start condition 6, it |
|
|
|
@ -2069,7 +2101,7 @@ _world_. |
|
|
|
</td></tr></table> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
In this case, the HTML block is terminated by the newline — the `**hello**` |
|
|
|
In this case, the HTML block is terminated by the newline — the `**Hello**` |
|
|
|
text remains verbatim — and regular parsing resumes, with a paragraph, |
|
|
|
emphasised `world` and inline and block HTML following. |
|
|
|
|
|
|
|
@ -2612,7 +2644,8 @@ bar |
|
|
|
|
|
|
|
|
|
|
|
However, a following blank line is needed, except at the end of |
|
|
|
a document, and except for blocks of types 1--5, above: |
|
|
|
a document, and except for blocks of types 1--5, [above][HTML |
|
|
|
block]: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
<div> |
|
|
|
@ -2758,8 +2791,8 @@ an indented code block: |
|
|
|
|
|
|
|
Fortunately, blank lines are usually not necessary and can be |
|
|
|
deleted. The exception is inside `<pre>` tags, but as described |
|
|
|
above, raw HTML blocks starting with `<pre>` *can* contain blank |
|
|
|
lines. |
|
|
|
[above][HTML blocks], raw HTML blocks starting with `<pre>` |
|
|
|
*can* contain blank lines. |
|
|
|
|
|
|
|
## Link reference definitions |
|
|
|
|
|
|
|
@ -2811,7 +2844,7 @@ them. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[Foo bar]: |
|
|
|
<my%20url> |
|
|
|
<my url> |
|
|
|
'title' |
|
|
|
|
|
|
|
[Foo bar] |
|
|
|
@ -2877,6 +2910,29 @@ The link destination may not be omitted: |
|
|
|
<p>[foo]</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
However, an empty link destination may be specified using |
|
|
|
angle brackets: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[foo]: <> |
|
|
|
|
|
|
|
[foo] |
|
|
|
. |
|
|
|
<p><a href="">foo</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
The title must be separated from the link destination by |
|
|
|
whitespace: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[foo]: <bar>(baz) |
|
|
|
|
|
|
|
[foo] |
|
|
|
. |
|
|
|
<p>[foo]: <bar>(baz)</p> |
|
|
|
<p>[foo]</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Both title and destination can contain backslash escapes |
|
|
|
and literal backslashes: |
|
|
|
@ -3034,6 +3090,25 @@ and thematic breaks, and it need not be followed by a blank line. |
|
|
|
</blockquote> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[foo]: /url |
|
|
|
bar |
|
|
|
=== |
|
|
|
[foo] |
|
|
|
. |
|
|
|
<h1>bar</h1> |
|
|
|
<p><a href="/url">foo</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[foo]: /url |
|
|
|
=== |
|
|
|
[foo] |
|
|
|
. |
|
|
|
<p>=== |
|
|
|
<a href="/url">foo</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Several [link reference definitions] |
|
|
|
can occur one after another, without intervening blank lines. |
|
|
|
@ -3070,6 +3145,17 @@ are defined: |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Whether something is a [link reference definition] is |
|
|
|
independent of whether the link reference it defines is |
|
|
|
used in the document. Thus, for example, the following |
|
|
|
document contains just a link reference definition, and |
|
|
|
no visible content: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[foo]: /url |
|
|
|
. |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
## Paragraphs |
|
|
|
|
|
|
|
@ -3207,7 +3293,7 @@ aaa |
|
|
|
|
|
|
|
# Container blocks |
|
|
|
|
|
|
|
A [container block] is a block that has other |
|
|
|
A [container block](#container-blocks) is a block that has other |
|
|
|
blocks as its contents. There are two basic kinds of container blocks: |
|
|
|
[block quotes] and [list items]. |
|
|
|
[Lists] are meta-containers for [list items]. |
|
|
|
@ -3669,9 +3755,8 @@ in some browsers.) |
|
|
|
The following rules define [list items]: |
|
|
|
|
|
|
|
1. **Basic case.** If a sequence of lines *Ls* constitute a sequence of |
|
|
|
blocks *Bs* starting with a [non-whitespace character] and not separated |
|
|
|
from each other by more than one blank line, and *M* is a list |
|
|
|
marker of width *W* followed by 1 ≤ *N* ≤ 4 spaces, then the result |
|
|
|
blocks *Bs* starting with a [non-whitespace character], and *M* is a |
|
|
|
list marker of width *W* followed by 1 ≤ *N* ≤ 4 spaces, then the result |
|
|
|
of prepending *M* and the following spaces to the first line of |
|
|
|
*Ls*, and indenting subsequent lines of *Ls* by *W + N* spaces, is a |
|
|
|
list item with *Bs* as its contents. The type of the list item |
|
|
|
@ -3981,8 +4066,7 @@ A start number may not be negative: |
|
|
|
|
|
|
|
2. **Item starting with indented code.** If a sequence of lines *Ls* |
|
|
|
constitute a sequence of blocks *Bs* starting with an indented code |
|
|
|
block and not separated from each other by more than one blank line, |
|
|
|
and *M* is a list marker of width *W* followed by |
|
|
|
block, and *M* is a list marker of width *W* followed by |
|
|
|
one space, then the result of prepending *M* and the following |
|
|
|
space to the first line of *Ls*, and indenting subsequent lines of |
|
|
|
*Ls* by *W + 1* spaces, is a list item with *Bs* as its contents. |
|
|
|
@ -4458,9 +4542,10 @@ continued here.</p> |
|
|
|
6. **That's all.** Nothing that is not counted as a list item by rules |
|
|
|
#1--5 counts as a [list item](#list-items). |
|
|
|
|
|
|
|
The rules for sublists follow from the general rules above. A sublist |
|
|
|
must be indented the same number of spaces a paragraph would need to be |
|
|
|
in order to be included in the list item. |
|
|
|
The rules for sublists follow from the general rules |
|
|
|
[above][List items]. A sublist must be indented the same number |
|
|
|
of spaces a paragraph would need to be in order to be included |
|
|
|
in the list item. |
|
|
|
|
|
|
|
So, in this case we need two spaces indent: |
|
|
|
|
|
|
|
@ -5049,11 +5134,9 @@ item: |
|
|
|
- b |
|
|
|
- c |
|
|
|
- d |
|
|
|
- e |
|
|
|
- f |
|
|
|
- g |
|
|
|
- h |
|
|
|
- i |
|
|
|
- e |
|
|
|
- f |
|
|
|
- g |
|
|
|
. |
|
|
|
<ul> |
|
|
|
<li>a</li> |
|
|
|
@ -5063,8 +5146,6 @@ item: |
|
|
|
<li>e</li> |
|
|
|
<li>f</li> |
|
|
|
<li>g</li> |
|
|
|
<li>h</li> |
|
|
|
<li>i</li> |
|
|
|
</ul> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
@ -5074,7 +5155,7 @@ item: |
|
|
|
|
|
|
|
2. b |
|
|
|
|
|
|
|
3. c |
|
|
|
3. c |
|
|
|
. |
|
|
|
<ol> |
|
|
|
<li> |
|
|
|
@ -5089,6 +5170,49 @@ item: |
|
|
|
</ol> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Note, however, that list items may not be indented more than |
|
|
|
three spaces. Here `- e` is treated as a paragraph continuation |
|
|
|
line, because it is indented more than three spaces: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
- a |
|
|
|
- b |
|
|
|
- c |
|
|
|
- d |
|
|
|
- e |
|
|
|
. |
|
|
|
<ul> |
|
|
|
<li>a</li> |
|
|
|
<li>b</li> |
|
|
|
<li>c</li> |
|
|
|
<li>d |
|
|
|
- e</li> |
|
|
|
</ul> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
And here, `3. c` is treated as in indented code block, |
|
|
|
because it is indented four spaces and preceded by a |
|
|
|
blank line. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
1. a |
|
|
|
|
|
|
|
2. b |
|
|
|
|
|
|
|
3. c |
|
|
|
. |
|
|
|
<ol> |
|
|
|
<li> |
|
|
|
<p>a</p> |
|
|
|
</li> |
|
|
|
<li> |
|
|
|
<p>b</p> |
|
|
|
</li> |
|
|
|
</ol> |
|
|
|
<pre><code>3. c |
|
|
|
</code></pre> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
This is a loose list, because there is a blank line between |
|
|
|
two of the list items: |
|
|
|
@ -5378,10 +5502,10 @@ Thus, for example, in |
|
|
|
<p><code>hi</code>lo`</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
`hi` is parsed as code, leaving the backtick at the end as a literal |
|
|
|
backtick. |
|
|
|
|
|
|
|
|
|
|
|
## Backslash escapes |
|
|
|
|
|
|
|
Any ASCII punctuation character may be backslash-escaped: |
|
|
|
@ -5415,6 +5539,7 @@ not have their usual Markdown meanings: |
|
|
|
\* not a list |
|
|
|
\# not a heading |
|
|
|
\[foo]: /url "not a reference" |
|
|
|
\ö not a character entity |
|
|
|
. |
|
|
|
<p>*not emphasized* |
|
|
|
<br/> not a tag |
|
|
|
@ -5423,7 +5548,8 @@ not have their usual Markdown meanings: |
|
|
|
1. not a list |
|
|
|
* not a list |
|
|
|
# not a heading |
|
|
|
[foo]: /url "not a reference"</p> |
|
|
|
[foo]: /url "not a reference" |
|
|
|
&ouml; not a character entity</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
@ -5521,13 +5647,23 @@ foo |
|
|
|
|
|
|
|
## Entity and numeric character references |
|
|
|
|
|
|
|
All valid HTML entity references and numeric character |
|
|
|
references, except those occuring in code blocks and code spans, |
|
|
|
are recognized as such and treated as equivalent to the |
|
|
|
corresponding Unicode characters. Conforming CommonMark parsers |
|
|
|
need not store information about whether a particular character |
|
|
|
was represented in the source using a Unicode character or |
|
|
|
an entity reference. |
|
|
|
Valid HTML entity references and numeric character references |
|
|
|
can be used in place of the corresponding Unicode character, |
|
|
|
with the following exceptions: |
|
|
|
|
|
|
|
- Entity and character references are not recognized in code |
|
|
|
blocks and code spans. |
|
|
|
|
|
|
|
- Entity and character references cannot stand in place of |
|
|
|
special characters that define structural elements in |
|
|
|
CommonMark. For example, although `*` can be used |
|
|
|
in place of a literal `*` character, `*` cannot replace |
|
|
|
`*` in emphasis delimiters, bullet list markers, or thematic |
|
|
|
breaks. |
|
|
|
|
|
|
|
Conforming CommonMark parsers need not store information about |
|
|
|
whether a particular character was represented in the source |
|
|
|
using a Unicode character or an entity reference. |
|
|
|
|
|
|
|
[Entity references](@) consist of `&` + any of the valid |
|
|
|
HTML5 entity names + `;`. The |
|
|
|
@ -5548,22 +5684,22 @@ references and their corresponding code points. |
|
|
|
|
|
|
|
[Decimal numeric character |
|
|
|
references](@) |
|
|
|
consist of `&#` + a string of 1--8 arabic digits + `;`. A |
|
|
|
consist of `&#` + a string of 1--7 arabic digits + `;`. A |
|
|
|
numeric character reference is parsed as the corresponding |
|
|
|
Unicode character. Invalid Unicode code points will be replaced by |
|
|
|
the REPLACEMENT CHARACTER (`U+FFFD`). For security reasons, |
|
|
|
the code point `U+0000` will also be replaced by `U+FFFD`. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
# Ӓ Ϡ � � |
|
|
|
# Ӓ Ϡ � |
|
|
|
. |
|
|
|
<p># Ӓ Ϡ � �</p> |
|
|
|
<p># Ӓ Ϡ �</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
[Hexadecimal numeric character |
|
|
|
references](@) consist of `&#` + |
|
|
|
either `X` or `x` + a string of 1-8 hexadecimal digits + `;`. |
|
|
|
either `X` or `x` + a string of 1-6 hexadecimal digits + `;`. |
|
|
|
They too are parsed as the corresponding Unicode character (this |
|
|
|
time specified with a hexadecimal numeral instead of decimal). |
|
|
|
|
|
|
|
@ -5578,9 +5714,13 @@ Here are some nonentities: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
  &x; &#; &#x; |
|
|
|
� |
|
|
|
&#abcdef0; |
|
|
|
&ThisIsNotDefined; &hi?; |
|
|
|
. |
|
|
|
<p>&nbsp &x; &#; &#x; |
|
|
|
&#987654321; |
|
|
|
&#abcdef0; |
|
|
|
&ThisIsNotDefined; &hi?;</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
@ -5661,6 +5801,51 @@ text in code spans and code blocks: |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Entity and numeric character references cannot be used |
|
|
|
in place of symbols indicating structure in CommonMark |
|
|
|
documents. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
*foo* |
|
|
|
*foo* |
|
|
|
. |
|
|
|
<p>*foo* |
|
|
|
<em>foo</em></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
* foo |
|
|
|
|
|
|
|
* foo |
|
|
|
. |
|
|
|
<p>* foo</p> |
|
|
|
<ul> |
|
|
|
<li>foo</li> |
|
|
|
</ul> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
foo bar |
|
|
|
. |
|
|
|
<p>foo |
|
|
|
|
|
|
|
bar</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
	foo |
|
|
|
. |
|
|
|
<p>→foo</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[a](url "tit") |
|
|
|
. |
|
|
|
<p>[a](url "tit")</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
## Code spans |
|
|
|
|
|
|
|
A [backtick string](@) |
|
|
|
@ -5669,9 +5854,16 @@ preceded nor followed by a backtick. |
|
|
|
|
|
|
|
A [code span](@) begins with a backtick string and ends with |
|
|
|
a backtick string of equal length. The contents of the code span are |
|
|
|
the characters between the two backtick strings, with leading and |
|
|
|
trailing spaces and [line endings] removed, and |
|
|
|
[whitespace] collapsed to single spaces. |
|
|
|
the characters between the two backtick strings, normalized in the |
|
|
|
following ways: |
|
|
|
|
|
|
|
- First, [line endings] are converted to [spaces]. |
|
|
|
- If the resulting string both begins *and* ends with a [space] |
|
|
|
character, but does not consist entirely of [space] |
|
|
|
characters, a single [space] character is removed from the |
|
|
|
front and back. This allows you to include code that begins |
|
|
|
or ends with backtick characters, which must be separated by |
|
|
|
whitespace from the opening or closing backtick strings. |
|
|
|
|
|
|
|
This is a simple code span: |
|
|
|
|
|
|
|
@ -5683,10 +5875,11 @@ This is a simple code span: |
|
|
|
|
|
|
|
|
|
|
|
Here two backticks are used, because the code contains a backtick. |
|
|
|
This example also illustrates stripping of leading and trailing spaces: |
|
|
|
This example also illustrates stripping of a single leading and |
|
|
|
trailing space: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`` foo ` bar `` |
|
|
|
`` foo ` bar `` |
|
|
|
. |
|
|
|
<p><code>foo ` bar</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
@ -5701,58 +5894,79 @@ spaces: |
|
|
|
<p><code>``</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Note that only *one* space is stripped: |
|
|
|
|
|
|
|
[Line endings] are treated like spaces: |
|
|
|
```````````````````````````````` example |
|
|
|
` `` ` |
|
|
|
. |
|
|
|
<p><code> `` </code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
The stripping only happens if the space is on both |
|
|
|
sides of the string: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`` |
|
|
|
foo |
|
|
|
`` |
|
|
|
` a` |
|
|
|
. |
|
|
|
<p><code>foo</code></p> |
|
|
|
<p><code> a</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Only [spaces], and not [unicode whitespace] in general, are |
|
|
|
stripped in this way: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
` b ` |
|
|
|
. |
|
|
|
<p><code> b </code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Interior spaces and [line endings] are collapsed into |
|
|
|
single spaces, just as they would be by a browser: |
|
|
|
No stripping occurs if the code span contains only spaces: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`foo bar |
|
|
|
baz` |
|
|
|
` ` |
|
|
|
` ` |
|
|
|
. |
|
|
|
<p><code>foo bar baz</code></p> |
|
|
|
<p><code> </code> |
|
|
|
<code> </code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Not all [Unicode whitespace] (for instance, non-breaking space) is |
|
|
|
collapsed, however: |
|
|
|
[Line endings] are treated like spaces: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`a b` |
|
|
|
`` |
|
|
|
foo |
|
|
|
bar |
|
|
|
baz |
|
|
|
`` |
|
|
|
. |
|
|
|
<p><code>a b</code></p> |
|
|
|
<p><code>foo bar baz</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`` |
|
|
|
foo |
|
|
|
`` |
|
|
|
. |
|
|
|
<p><code>foo </code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Q: Why not just leave the spaces, since browsers will collapse them |
|
|
|
anyway? A: Because we might be targeting a non-HTML format, and we |
|
|
|
shouldn't rely on HTML-specific rendering assumptions. |
|
|
|
|
|
|
|
(Existing implementations differ in their treatment of internal |
|
|
|
spaces and [line endings]. Some, including `Markdown.pl` and |
|
|
|
`showdown`, convert an internal [line ending] into a |
|
|
|
`<br />` tag. But this makes things difficult for those who like to |
|
|
|
hard-wrap their paragraphs, since a line break in the midst of a code |
|
|
|
span will cause an unintended line break in the output. Others just |
|
|
|
leave internal spaces as they are, which is fine if only HTML is being |
|
|
|
targeted.) |
|
|
|
Interior spaces are not collapsed: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
`foo `` bar` |
|
|
|
`foo bar |
|
|
|
baz` |
|
|
|
. |
|
|
|
<p><code>foo `` bar</code></p> |
|
|
|
<p><code>foo bar baz</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Note that browsers will typically collapse consecutive spaces |
|
|
|
when rendering `<code>` elements, so it is recommended that |
|
|
|
the following CSS be used: |
|
|
|
|
|
|
|
code{white-space: pre-wrap;} |
|
|
|
|
|
|
|
|
|
|
|
Note that backslash escapes do not work in code spans. All backslashes |
|
|
|
are treated literally: |
|
|
|
@ -5768,6 +5982,19 @@ Backslash escapes are never needed, because one can always choose a |
|
|
|
string of *n* backtick characters as delimiters, where the code does |
|
|
|
not contain any strings of exactly *n* backtick characters. |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
``foo`bar`` |
|
|
|
. |
|
|
|
<p><code>foo`bar</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
` foo `` bar ` |
|
|
|
. |
|
|
|
<p><code>foo `` bar</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Code span backticks have higher precedence than any other inline |
|
|
|
constructs except HTML tags and autolinks. Thus, for example, this is |
|
|
|
not parsed as emphasized text, since the second `*` is part of a code |
|
|
|
@ -5905,15 +6132,17 @@ of one or more `_` characters that is not preceded or followed by |
|
|
|
a non-backslash-escaped `_` character. |
|
|
|
|
|
|
|
A [left-flanking delimiter run](@) is |
|
|
|
a [delimiter run] that is (a) not followed by [Unicode whitespace], |
|
|
|
and (b) not followed by a [punctuation character], or |
|
|
|
a [delimiter run] that is (1) not followed by [Unicode whitespace], |
|
|
|
and either (2a) not followed by a [punctuation character], or |
|
|
|
(2b) followed by a [punctuation character] and |
|
|
|
preceded by [Unicode whitespace] or a [punctuation character]. |
|
|
|
For purposes of this definition, the beginning and the end of |
|
|
|
the line count as Unicode whitespace. |
|
|
|
|
|
|
|
A [right-flanking delimiter run](@) is |
|
|
|
a [delimiter run] that is (a) not preceded by [Unicode whitespace], |
|
|
|
and (b) not preceded by a [punctuation character], or |
|
|
|
a [delimiter run] that is (1) not preceded by [Unicode whitespace], |
|
|
|
and either (2a) not preceded by a [punctuation character], or |
|
|
|
(2b) preceded by a [punctuation character] and |
|
|
|
followed by [Unicode whitespace] or a [punctuation character]. |
|
|
|
For purposes of this definition, the beginning and the end of |
|
|
|
the line count as Unicode whitespace. |
|
|
|
@ -6005,7 +6234,8 @@ The following rules define emphasis and strong emphasis: |
|
|
|
[delimiter runs]. If one of the delimiters can both |
|
|
|
open and close emphasis, then the sum of the lengths of the |
|
|
|
delimiter runs containing the opening and closing delimiters |
|
|
|
must not be a multiple of 3. |
|
|
|
must not be a multiple of 3 unless both lengths are |
|
|
|
multiples of 3. |
|
|
|
|
|
|
|
10. Strong emphasis begins with a delimiter that |
|
|
|
[can open strong emphasis] and ends with a delimiter that |
|
|
|
@ -6015,7 +6245,8 @@ The following rules define emphasis and strong emphasis: |
|
|
|
[delimiter runs]. If one of the delimiters can both open |
|
|
|
and close strong emphasis, then the sum of the lengths of |
|
|
|
the delimiter runs containing the opening and closing |
|
|
|
delimiters must not be a multiple of 3. |
|
|
|
delimiters must not be a multiple of 3 unless both lengths |
|
|
|
are multiples of 3. |
|
|
|
|
|
|
|
11. A literal `*` character cannot occur at the beginning or end of |
|
|
|
`*`-delimited emphasis or `**`-delimited strong emphasis, unless it |
|
|
|
@ -6634,7 +6865,19 @@ is precluded by the condition that a delimiter that |
|
|
|
can both open and close (like the `*` after `foo`) |
|
|
|
cannot form emphasis if the sum of the lengths of |
|
|
|
the delimiter runs containing the opening and |
|
|
|
closing delimiters is a multiple of 3. |
|
|
|
closing delimiters is a multiple of 3 unless |
|
|
|
both lengths are multiples of 3. |
|
|
|
|
|
|
|
|
|
|
|
For the same reason, we don't get two consecutive |
|
|
|
emphasis sections in this example: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
*foo**bar* |
|
|
|
. |
|
|
|
<p><em>foo**bar</em></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
The same condition ensures that the following |
|
|
|
cases are all strong emphasis nested inside |
|
|
|
@ -6663,6 +6906,23 @@ omitted: |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
When the lengths of the interior closing and opening |
|
|
|
delimiter runs are *both* multiples of 3, though, |
|
|
|
they can match to create emphasis: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
foo***bar***baz |
|
|
|
. |
|
|
|
<p>foo<em><strong>bar</strong></em>baz</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
foo******bar*********baz |
|
|
|
. |
|
|
|
<p>foo<strong><strong><strong>bar</strong></strong></strong>***baz</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
Indefinite levels of nesting are possible: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
@ -7198,15 +7458,16 @@ following rules apply: |
|
|
|
A [link destination](@) consists of either |
|
|
|
|
|
|
|
- a sequence of zero or more characters between an opening `<` and a |
|
|
|
closing `>` that contains no spaces, line breaks, or unescaped |
|
|
|
closing `>` that contains no line breaks or unescaped |
|
|
|
`<` or `>` characters, or |
|
|
|
|
|
|
|
- a nonempty sequence of characters that does not include |
|
|
|
ASCII space or control characters, and includes parentheses |
|
|
|
only if (a) they are backslash-escaped or (b) they are part of |
|
|
|
a balanced pair of unescaped parentheses. (Implementations |
|
|
|
may impose limits on parentheses nesting to avoid performance |
|
|
|
issues, but at least three levels of nesting should be supported.) |
|
|
|
- a nonempty sequence of characters that does not start with |
|
|
|
`<`, does not include ASCII space or control characters, and |
|
|
|
includes parentheses only if (a) they are backslash-escaped or |
|
|
|
(b) they are part of a balanced pair of unescaped parentheses. |
|
|
|
(Implementations may impose limits on parentheses nesting to |
|
|
|
avoid performance issues, but at least three levels of nesting |
|
|
|
should be supported.) |
|
|
|
|
|
|
|
A [link title](@) consists of either |
|
|
|
|
|
|
|
@ -7219,7 +7480,8 @@ A [link title](@) consists of either |
|
|
|
backslash-escaped, or |
|
|
|
|
|
|
|
- a sequence of zero or more characters between matching parentheses |
|
|
|
(`(...)`), including a `)` character only if it is backslash-escaped. |
|
|
|
(`(...)`), including a `(` or `)` character only if it is |
|
|
|
backslash-escaped. |
|
|
|
|
|
|
|
Although [link titles] may span multiple lines, they may not contain |
|
|
|
a [blank line]. |
|
|
|
@ -7269,9 +7531,8 @@ Both the title and the destination may be omitted: |
|
|
|
<p><a href="">link</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
The destination cannot contain spaces or line breaks, |
|
|
|
even if enclosed in pointy brackets: |
|
|
|
The destination can only contain spaces if it is |
|
|
|
enclosed in pointy brackets: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[link](/my uri) |
|
|
|
@ -7279,13 +7540,14 @@ even if enclosed in pointy brackets: |
|
|
|
<p>[link](/my uri)</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[link](</my uri>) |
|
|
|
. |
|
|
|
<p>[link](</my uri>)</p> |
|
|
|
<p><a href="/my%20uri">link</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
The destination cannot contain line breaks, |
|
|
|
even if enclosed in pointy brackets: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[link](foo |
|
|
|
@ -7295,7 +7557,6 @@ bar) |
|
|
|
bar)</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[link](<foo |
|
|
|
bar>) |
|
|
|
@ -7304,6 +7565,36 @@ bar>) |
|
|
|
bar>)</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
The destination can contain `)` if it is enclosed |
|
|
|
in pointy brackets: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[a](<b)c>) |
|
|
|
. |
|
|
|
<p><a href="b)c">a</a></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Pointy brackets that enclose links must be unescaped: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[link](<foo\>) |
|
|
|
. |
|
|
|
<p>[link](<foo>)</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
These are not links, because the opening pointy bracket |
|
|
|
is not matched properly: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
[a](<b)c |
|
|
|
[a](<b)c> |
|
|
|
[a](<b>c) |
|
|
|
. |
|
|
|
<p>[a](<b)c |
|
|
|
[a](<b)c> |
|
|
|
[a](<b>c)</p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
Parentheses inside the link destination may be escaped: |
|
|
|
|
|
|
|
```````````````````````````````` example |
|
|
|
@ -8411,7 +8702,7 @@ If you want a link after a literal `!`, backslash-escape the |
|
|
|
as the link label. |
|
|
|
|
|
|
|
A [URI autolink](@) consists of `<`, followed by an |
|
|
|
[absolute URI] not containing `<`, followed by `>`. It is parsed as |
|
|
|
[absolute URI] followed by `>`. It is parsed as |
|
|
|
a link to the URI, with the URI as the link's label. |
|
|
|
|
|
|
|
An [absolute URI](@), |
|
|
|
@ -8624,7 +8915,7 @@ a [single-quoted attribute value], or a [double-quoted attribute value]. |
|
|
|
|
|
|
|
An [unquoted attribute value](@) |
|
|
|
is a nonempty string of characters not |
|
|
|
including spaces, `"`, `'`, `=`, `<`, `>`, or `` ` ``. |
|
|
|
including [whitespace], `"`, `'`, `=`, `<`, `>`, or `` ` ``. |
|
|
|
|
|
|
|
A [single-quoted attribute value](@) |
|
|
|
consists of `'`, zero or more |
|
|
|
@ -8745,9 +9036,13 @@ Illegal [whitespace]: |
|
|
|
```````````````````````````````` example |
|
|
|
< a>< |
|
|
|
foo><bar/ > |
|
|
|
<foo bar=baz |
|
|
|
bim!bop /> |
|
|
|
. |
|
|
|
<p>< a>< |
|
|
|
foo><bar/ ></p> |
|
|
|
foo><bar/ > |
|
|
|
<foo bar=baz |
|
|
|
bim!bop /></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
@ -8947,7 +9242,7 @@ Line breaks do not occur inside code spans |
|
|
|
`code |
|
|
|
span` |
|
|
|
. |
|
|
|
<p><code>code span</code></p> |
|
|
|
<p><code>code span</code></p> |
|
|
|
```````````````````````````````` |
|
|
|
|
|
|
|
|
|
|
|
@ -9365,7 +9660,8 @@ just above `stack_bottom` (or the first element if `stack_bottom` |
|
|
|
is NULL). |
|
|
|
|
|
|
|
We keep track of the `openers_bottom` for each delimiter |
|
|
|
type (`*`, `_`). Initialize this to `stack_bottom`. |
|
|
|
type (`*`, `_`) and each length of the closing delimiter run |
|
|
|
(modulo 3). Initialize this to `stack_bottom`. |
|
|
|
|
|
|
|
Then we repeat the following until we run out of potential |
|
|
|
closers: |
|
|
|
@ -9397,7 +9693,7 @@ closers: |
|
|
|
of the delimiter stack. If the closing node is removed, reset |
|
|
|
`current_position` to the next element in the stack. |
|
|
|
|
|
|
|
- If none in found: |
|
|
|
- If none is found: |
|
|
|
|
|
|
|
+ Set `openers_bottom` to the element before `current_position`. |
|
|
|
(We know that there are no openers for this kind of closer up to and |
|
|
|
|
Alex Kocharin
6 years ago