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-rw-r--r--spec.txt131
1 files changed, 97 insertions, 34 deletions
diff --git a/spec.txt b/spec.txt
index bc2e381..0c09c43 100644
--- a/spec.txt
+++ b/spec.txt
@@ -1355,8 +1355,8 @@ name is one of the following (case-insensitive):
`output`, `col`, `p`, `colgroup`, `pre`, `dd`, `progress`, `div`,
`section`, `dl`, `table`, `td`, `dt`, `tbody`, `embed`, `textarea`,
`fieldset`, `tfoot`, `figcaption`, `th`, `figure`, `thead`, `footer`,
-`footer`, `tr`, `form`, `ul`, `h1`, `h2`, `h3`, `h4`, `h5`, `h6`,
-`video`, `script`, `style`.
+`tr`, `form`, `ul`, `h1`, `h2`, `h3`, `h4`, `h5`, `h6`, `video`,
+`script`, `style`.
An [HTML block](#html-block) <a id="html-block"></a> begins with an
[HTML block tag](#html-block-tag), [HTML comment](#html-comment),
@@ -3727,21 +3727,25 @@ foo
## Entities
-With the goal of making this standard as HTML-agnostic as possible, all HTML valid HTML Entities in any
-context are recognized as such and converted into their actual values (i.e. the UTF8 characters representing
-the entity itself) before they are stored in the AST.
+With the goal of making this standard as HTML-agnostic as possible, all
+valid HTML entities in any context are recognized as such and
+converted into unicode characters before they are stored in the AST.
-This allows implementations that target HTML output to trivially escape the entities when generating HTML,
-and simplifies the job of implementations targetting other languages, as these will only need to handle the
-UTF8 chars and need not be HTML-entity aware.
+This allows implementations that target HTML output to trivially escape
+the entities when generating HTML, and simplifies the job of
+implementations targetting other languages, as these will only need to
+handle the unicode chars and need not be HTML-entity aware.
[Named entities](#name-entities) <a id="named-entities"></a> consist of `&`
-+ any of the valid HTML5 entity names + `;`. The [following document](http://www.whatwg.org/specs/web-apps/current-work/multipage/entities.json)
-is used as an authoritative source of the valid entity names and their corresponding codepoints.
++ any of the valid HTML5 entity names + `;`. The
+[following document](http://www.whatwg.org/specs/web-apps/current-work/multipage/entities.json)
+is used as an authoritative source of the valid entity names and their
+corresponding codepoints.
-Conforming implementations that target Markdown don't need to generate entities for all the valid
-named entities that exist, with the exception of `"` (`&quot;`), `&` (`&amp;`), `<` (`&lt;`) and `>` (`&gt;`),
-which always need to be written as entities for security reasons.
+Conforming implementations that target HTML don't need to generate
+entities for all the valid named entities that exist, with the exception
+of `"` (`&quot;`), `&` (`&amp;`), `<` (`&lt;`) and `>` (`&gt;`), which
+always need to be written as entities for security reasons.
.
&nbsp; &amp; &copy; &AElig; &Dcaron; &frac34; &HilbertSpace; &DifferentialD; &ClockwiseContourIntegral;
@@ -3750,9 +3754,10 @@ which always need to be written as entities for security reasons.
.
[Decimal entities](#decimal-entities) <a id="decimal-entities"></a>
-consist of `&#` + a string of 1--8 arabic digits + `;`. Again, these entities need to be recognised
-and tranformed into their corresponding UTF8 codepoints. Invalid Unicode codepoints will be written
-as the "unknown codepoint" character (`0xFFFD`)
+consist of `&#` + a string of 1--8 arabic digits + `;`. Again, these
+entities need to be recognised and tranformed into their corresponding
+UTF8 codepoints. Invalid Unicode codepoints will be written as the
+"unknown codepoint" character (`0xFFFD`)
.
&#35; &#1234; &#992; &#98765432;
@@ -3779,7 +3784,8 @@ Here are some nonentities:
.
Although HTML5 does accept some entities without a trailing semicolon
-(such as `&copy`), these are not recognized as entities here, because it makes the grammar too ambiguous:
+(such as `&copy`), these are not recognized as entities here, because it
+makes the grammar too ambiguous:
.
&copy
@@ -3787,7 +3793,8 @@ Although HTML5 does accept some entities without a trailing semicolon
<p>&amp;copy</p>
.
-Strings that are not on the list of HTML5 named entities are not recognized as entities either:
+Strings that are not on the list of HTML5 named entities are not
+recognized as entities either:
.
&MadeUpEntity;
@@ -4035,7 +4042,7 @@ for efficient parsing strategies that do not backtrack:
(a) it is not part of a sequence of four or more unescaped `*`s,
(b) it is not followed by whitespace, and
(c) either it is not followed by a `*` character or it is
- followed immediately by strong emphasis.
+ followed immediately by emphasis or strong emphasis.
2. A single `_` character [can open emphasis](#can-open-emphasis) iff
@@ -4043,7 +4050,7 @@ for efficient parsing strategies that do not backtrack:
(b) it is not followed by whitespace,
(c) it is not preceded by an ASCII alphanumeric character, and
(d) either it is not followed by a `_` character or it is
- followed immediately by strong emphasis.
+ followed immediately by emphasis or strong emphasis.
3. A single `*` character [can close emphasis](#can-close-emphasis)
<a id="can-close-emphasis"></a> iff
@@ -4099,6 +4106,11 @@ for efficient parsing strategies that do not backtrack:
emphasis](#can-close-strong-emphasis), and that uses the
same character (`_` or `*`) as the opening delimiter, is reached.
+11. In case of ambiguity, strong emphasis takes precedence. Thus,
+ `**foo**` is `<strong>foo</strong>`, not `<em><em>foo</em></em>`,
+ and `***foo***` is `<strong><em>foo</em></strong>`, not
+ `<em><strong>foo</strong></em>` or `<em><em><em>foo</em></em></em>`.
+
These rules can be illustrated through a series of examples.
Simple emphasis:
@@ -4345,6 +4357,32 @@ __this is a double underscore (`__`)__
<p><strong>this is a double underscore (<code>__</code>)</strong></p>
.
+Or use the other emphasis character:
+
+.
+*_*
+.
+<p><em>_</em></p>
+.
+
+.
+_*_
+.
+<p><em>*</em></p>
+.
+
+.
+*__*
+.
+<p><em>__</em></p>
+.
+
+.
+_**_
+.
+<p><em>**</em></p>
+.
+
`*` delimiters allow intra-word emphasis; `_` delimiters do not:
.
@@ -4520,6 +4558,36 @@ __foo _bar_ baz__
<p><strong>foo <em>bar</em> baz</strong></p>
.
+.
+**foo, *bar*, baz**
+.
+<p><strong>foo, <em>bar</em>, baz</strong></p>
+.
+
+.
+__foo, _bar_, baz__
+.
+<p><strong>foo, <em>bar</em>, baz</strong></p>
+.
+
+But note:
+
+.
+*foo**bar**baz*
+.
+<p><em>foo</em><em>bar</em><em>baz</em></p>
+.
+
+.
+**foo*bar*baz**
+.
+<p><em><em>foo</em>bar</em>baz**</p>
+.
+
+The difference is that in the two preceding cases,
+the internal delimiters [can close emphasis](#can-close-emphasis),
+while in the cases with spaces, they cannot.
+
Note that you cannot nest emphasis directly inside emphasis
using the same delimeter, or strong emphasis directly inside
strong emphasis:
@@ -4601,7 +4669,7 @@ However, a string of four or more `****` can never close emphasis:
<p>*foo****</p>
.
-Note that there are some asymmetries here:
+We retain symmetry in these cases:
.
*foo**
@@ -4609,7 +4677,7 @@ Note that there are some asymmetries here:
**foo*
.
<p><em>foo</em>*</p>
-<p>**foo*</p>
+<p>*<em>foo</em></p>
.
.
@@ -4618,18 +4686,12 @@ Note that there are some asymmetries here:
**foo* bar*
.
<p><em>foo <em>bar</em></em></p>
-<p>**foo* bar*</p>
+<p><em><em>foo</em> bar</em></p>
.
More cases with mismatched delimiters:
.
-**foo* bar*
-.
-<p>**foo* bar*</p>
-.
-
-.
*bar***
.
<p><em>bar</em>**</p>
@@ -4638,7 +4700,7 @@ More cases with mismatched delimiters:
.
***foo*
.
-<p>***foo*</p>
+<p>**<em>foo</em></p>
.
.
@@ -4650,7 +4712,7 @@ More cases with mismatched delimiters:
.
***foo**
.
-<p>***foo**</p>
+<p>*<strong>foo</strong></p>
.
.
@@ -4817,9 +4879,10 @@ in Markdown:
<p><a href="foo):">link</a></p>
.
-URL-escaping and should be left alone inside the destination, as all URL-escaped characters
-are also valid URL characters. HTML entities in the destination will be parsed into their UTF8
-codepoints, as usual, and optionally URL-escaped when written as HTML.
+URL-escaping should be left alone inside the destination, as all
+URL-escaped characters are also valid URL characters. HTML entities in
+the destination will be parsed into their UTF-8 codepoints, as usual, and
+optionally URL-escaped when written as HTML.
.
[link](foo%20b&auml;)