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<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>CSS Syntax Module Level 3 (CSS3 Syntax)</title>
<link rel=contents href="#contents">
<link rel=index href="#index">
<link rel="stylesheet" type="text/css" href="../default.css">
<link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
<link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-[STATUS].css">
<link rel="stylesheet" type="text/css" href="railroad-diagrams.css">
</head>
<div class="head">
<!--logo-->
<h1>CSS Syntax Module Level 3</h1>
<h2 class="no-num no-toc">[LONGSTATUS] [DATE]</h2>
<dl>
<dt>This version:
<dd>
<a href="http://dev.w3.org/csswg/css3-syntax/">http://dev.w3.org/csswg/css3-syntax/</a>
<!--
<dt>Latest version:
<dd>
<a href="http://www.w3.org/TR/css3-syntax/">http://www.w3.org/TR/css3-syntax/</a>
-->
<dt>Editor's draft:
<dd>
<a href="http://dev.w3.org/csswg/css3-syntax/">http://dev.w3.org/csswg/css3-syntax/</a>
<dt>Previous version:
<dd>
<a href="http://www.w3.org/TR/2003/WD-css3-syntax-20030813/">http://www.w3.org/TR/2003/WD-css3-syntax-20030813/</a>
<dt>Issue Tracking:
<dd>
<a href="https://www.w3.org/Bugs/Public/buglist.cgi?product=CSS&component=Syntax">W3C Bugzilla</a>
<dt>Feedback:
<dd>
<a href="http://lists.w3.org/Archives/Public/www-style/">www-style@w3.org</a>
with subject line “<kbd>[css3-syntax] <var>… message topic …</var></kbd>”
<dt>Editors:
<dd class="h-card vcard">
<a class="p-name fn u-url url" rel="author"
href="http://www.xanthir.com/">Tab Atkins Jr.</a>
(<span class="p-org org">Google, Inc.</span>),
<span class="u-email email">jackalmage@gmail.com</span>
</dl>
<!--copyright-->
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc" id="abstract">Abstract</h2>
<p>
<a href="http://www.w3.org/TR/CSS/">CSS</a> is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc.
This module describes, in general terms, the basic structure and syntax of CSS stylesheets.
It defines, in detail, the syntax and parsing of CSS - how to turn a stream of bytes into a meaningful stylesheet.
<h2 class="no-num no-toc" id="status">Status of this document</h2>
<!--status-->
<p>The following features are at risk: …
<h2 class="no-num no-toc" id="contents">
Table of contents</h2>
<!--toc-->
<h2 id="intro">
Introduction</h2>
<p><em>This section is not normative.</em>
<p>
This module defines the abstract syntax and parsing of CSS stylesheets
and other things which use CSS syntax
(such as the HTML <code>style</code> attribute).
<p>
It defines algorithms for converting a stream of codepoints
(in other words, text)
into a stream of CSS tokens,
and then further into CSS objects
such as stylesheets, rules, and declarations.
<h3 id="placement">
Module interactions</h3>
<p>
This module defines the syntax and parsing of CSS stylesheets.
It supersedes the lexical scanner and grammar defined in CSS 2.1.
<h2 id='syntax-description'>
Description of CSS's Syntax</h2>
<p><em>This section is not normative.</em>
<p>
A CSS document is a series of <i>style rules</i>,
which apply CSS properties to elements in the source document,
and <i>at-rules</i>,
which define special processing rules or values for the CSS document.
<p>
A <dfn>style rule</dfn> starts with a selector
(defined by the <a href="http://www.w3.org/TR/selectors/">Selectors specification</a>),
then has a {}-wrapped block containing a sequence of declarations.
The selector specifies which elements the declarations will apply to.
Each declaration has a property name,
followed by a colon and the property value,
and finished with a semicolon.
<div class='example'>
<p>
A typical rule might look something like this:
<pre>
p > a {
color: blue;
text-decoration: underline;
}</pre>
<p>
In the above rule, "<code>p > a</code>" is the selector,
which, if the source document is HTML,
selects any <code><a></code> elements that are children of a <code><p></code> element.
<p>
"<code>color: blue;</code>" is a declaration specifying that,
for the elements that match the selector,
their 'color' property should have the value ''blue''.
Similiarly, their 'text-decoration' property should have the value ''underline''.
</div>
<p>
<dfn title="at-rule">At-rules</dfn> are all different, but they have a basic structure in common.
They start with an "@" character followed by their name.
Some <i>at-rules</i> are simple statements,
with their name followed by more CSS values to specify their behavior,
and finally ended by a semicolon.
Others are blocks;
they can have CSS values following their name,
but they end with a {}-wrapped block,
similar to a <i>rule</i>.
Even the contents of these blocks are specific to the given <i>at-rule</i>:
sometimes they contain a sequence of declarations, like a <i>rule</i>;
other times, they may contain additional blocks, or at-rules, or other structures altogether.
<div class='example'>
<p>
Here are several examples of <i>at-rules</i> that illustrate the varied syntax they may contain.
<pre>@import "my-styles.css";</pre>
<p>
The ''@import'' <i>at-rule</i> is a simple statement.
After its name, it takes a single string or ''url()'' function to indicate the stylesheet that it should import.
<pre>
@page :left {
margin-left: 4cm;
margin-right: 3cm;
}</pre>
<p>
The ''@page'' <i>at-rule</i> consists of an optional page selector (the ":left" pseudoclass),
followed by a block of properties that apply to the page when printed.
In this way, it's very similar to a normal <i>style rule</i>,
except that its properties don't apply to any "element",
but rather the page itself.
<pre>
@media print {
body { font-size: 10pt }
}</pre>
<p>
The ''@media'' <i>at-rule</i> begins with a media type
and a list of optional media queries.
Its block contains entire rules,
which are only applied when the ''@media''s conditions are fulfilled.
</div>
<p>
Property names and <i>at-rule</i> names are always <b>idents</b>,
which have to start with a letter or a hyphen followed by a letter,
and then can contain letters, numbers, hyphens, or underscores.
You can include any character at all,
even ones that CSS uses in its syntax,
by escaping it with a backslash (\) or by using a hexadecimal escape.
<p>
The syntax of selectors is defined in the <a href="http://www.w3.org/TR/selectors/">Selectors spec</a>.
Similarly, the syntax of the wide variety of CSS values is defined in the <a href="http://www.w3.org/TR/css3-values/">Values & Units spec</a>.
The special syntaxes of individual <i>at-rules</i> can be found in the specs that define them.
<h2>
Tokenizing and Parsing CSS</h2>
<p>
User agents must use the parsing rules described in this specifiction
to generate the CSSOM trees from text/css resources.
Together, these rules define what is referred to as the CSS parser.
<p>
This specification defines the parsing rules for CSS documents,
whether they are syntactically correct or not.
Certain points in the parsing algorithm are said to be parse errors.
The error handling for parse errors is well-defined:
user agents must either act as described below when encountering such problems,
or must abort processing at the first error that they encounter for which they do not wish to apply the rules described below.
<p>
Conformance checkers must report at least one parse error condition to the user
if one or more parse error conditions exist in the document
and must not report parse error conditions
if none exist in the document.
Conformance checkers may report more than one parse error condition if more than one parse error condition exists in the document.
Conformance checkers are not required to recover from parse errors.
<h3>
Overview of the Parsing Model</h3>
<p>
The input to the CSS parsing process consists of a stream of Unicode code points,
which is passed through a tokenization stage followed by a tree construction stage.
The output is a CSSStyleSheet object.
<p class='note'>
Implementations that do not support scripting do not have to actually create a CSSOM CSSStyleSheet object,
but the CSSOM tree in such cases is still used as the model for the rest of the specification.
<h3>
The input byte stream</h3>
<p>
The stream of Unicode code points that comprises the input to the tokenization stage will be initially seen by the user agent as a stream of bytes
(typically coming over the network or from the local file system).
The bytes encode the actual characters according to a particular character encoding,
which the user agent must use to decode the bytes into characters.
<p>
To decode the stream of bytes into a stream of characters,
UAs must follow these steps.
<p>
The algorithms to <a href="http://encoding.spec.whatwg.org/#concept-encoding-get"><dfn>get an encoding</dfn></a>
and <a href="http://encoding.spec.whatwg.org/#decode"><dfn>decode</dfn></a>
are defined in the <a href="http://encoding.spec.whatwg.org/">Encoding Standard</a>.
<ol>
<li>
Let <var>encoding</var> be utf-8.
<li>
If HTTP or equivalent protocol defines an encoding (e.g. via the charset parameter of the Content-Type header),
<i>get an encoding</i> for the specified value.
If that does not return failure,
set <var>encoding</var> to the return value
and jump to the last step of this algorithm.
<li>
Check the byte stream. If the first several bytes match the hex sequence
<pre>40 63 68 61 72 73 65 74 20 22 (XX)* 22 3B</pre>
then <i>get an encoding</i> for the sequence of XX bytes,
decoded per <code>windows-1252</code>,
and let <var>temp</var> be the return value.
<p class='note'>
Note: Anything ASCII-compatible will do, so using <code>windows-1252</code> is fine.
<p class='note'>
Note: The byte sequence above,
when decoded as ASCII,
is the string "<code>@charset "…";</code>",
where the "…" is the sequence of bytes corresponding to the encoding's name.
<p>
If <var>temp</var> is <code>utf-16</code> or <code>utf-16be</code>,
set <var>temp</var> to <code>utf-8</code>.
If <var>temp</var> is not failure,
set <var>encoding</var> to it
and jump to the last step.
<p class='note'>
This mimics HTML <code><meta></code> behavior.
<li>
<i>Get an encoding</i> for the value of the <code>charset</code> attribute on the <code><link></code> element or <code><?xml-stylesheet?></code> processing instruction that caused the style sheet to be included, if any.
If that does not return failure,
set <var>encoding</var> to the return value
and jump to the last step.
<li>
Set <var>encoding</var> to the encoding of the referring style sheet or document,
if any.
<li>
<i>Decode</i> the byte stream using fallback encoding <var>encoding</var>.
<p class='note'>
Note: the <i>decode</i> algorithm lets the byte order mark (BOM) take precedence,
hence the usage of the term "fallback" above.
</ol>
<p class='issue'>
Anne says that steps 4/5 should be an input to this algorithm from the specs that define importing stylesheet,
to make the algorithm as a whole cleaner.
Perhaps abstract it into the concept of an "environment charset" or something?
<h4>
Preprocessing the input stream</h4>
<p>
The input stream consists of the characters pushed into it as the input byte stream is decoded.
<p>
Before sending the input stream to the tokenizer,
implementations must make the following character substitutions:
<ul>
<li>
Replace any U+000D CARRIAGE RETURN (CR) characters
or pairs of U+000D CARRIAGE RETURN (CR) followed by U+000A LINE FEED (LF)
by a single U+000A LINE FEED (LF) character.
<li>
Replace any U+0000 NULL characters with U+FFFD REPLACEMENT CHARACTER (�).
</ul>
<p>
The <dfn>next input character</dfn> is the first character in the input stream that has not yet been consumed or explicitly ignored by the requirements in this section. Initially, the <i>next input character</i> is the first character in the input. The <dfn>current input character</dfn> is the last character to have been consumed.
<p>
The "EOF" character in the tables below is a conceptual character representing the end of the input stream.
<h2>
Tokenization</h2>
<p>
Implementations must act as if they used the following state machine to tokenize CSS.
The state machine must start in the <i>data state</i>.
Most states consume a single character,
which may have various side-effects,
and either switches the state machine to a new state to reconsume the same character,
or switches it to a new state to consume the next character,
or stays in the same state to consume the next character.
Some states have more complicated behavior and can consume several characters before switching to another state.
<p>
The output of the tokenization step is a series of zero or more of the following tokens:
ident,
function,
at-keyword,
hash,
string,
bad-string,
url,
bad-url,
delim,
number,
percentage,
dimension,
unicode-range,
include-match,
dash-match,
prefix-match,
suffix-match,
substring-match,
whitespace,
cdo,
cdc,
colon,
semicolon,
[,
],
(,
),
{,
}.
<p>
ident, function, at-keyword, hash, string, and url tokens have a value composed of zero or more characters.
Delim tokens have a value composed of a single character.
Number, percentage, and dimension tokens have a representation composed of 1 or more character, a numeric value, and a type flag set to either "integer" or "number". The type flag defaults to "integer" if not otherwise set.
Dimension tokens additionally have a unit composed of one or more characters.
Unicode-range tokens have a range of characters.
<p class='issue'>
Several types of tokens that are guaranteed to be language-defined,
like at-keywords, functions, or dimension units,
are always lowercased when serialized.
Should we eagerly lowercase them in the parser,
or leave that to serialization to deal with?
(I slightly lean toward letting serialization deal with it,
so we don't mess with the capitalization of variable values.)
<p>
The tokenizer state machine consists of the states defined in the following subsections.
<h3 id='token-diagrams'>
Token Railroad Diagrams</h3>
<p>
<em>This section is non-normative.</em>
<p>
This section presents an informative view of the token parser,
in the form of railroad diagrams.
Railroad diagrams are more compact than a state-machine,
but often easier to read than a regular expression.
<p>
These diagrams are <em>informative</em> and <em>incomplete</em>;
they describe the grammar of "correct" tokens,
but do not describe error-handling at all.
They are provided solely to make it easier to get an intuitive grasp of the syntax of each token.
<!--
The "source" of these diagrams is in ./Diagrams.src.html
The generated SVG is copied here so that JavaScript is not required
to view the spec.
-->
<dl>
<dt id="escape-diagram">escape</dt>
<dd><svg class="railroad-diagram" width="377" height="122"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M78 31h0"></path><rect x="50" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="64" y="35">\</text></g><path d="M78 31h10"></path><g><path d="M88 31h0"></path><path d="M336 31h0"></path><path d="M88 31h20"></path><g><path d="M108 31h18"></path><path d="M298 31h18"></path><rect x="126" y="20" width="172" height="22"></rect><text x="212" y="35">not NL or hex digit</text></g><path d="M316 31h20"></path><path d="M88 31a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M108 61h0"></path><path d="M316 61h0"></path><path d="M108 61h10"></path><g><path d="M118 61h0"></path><path d="M230 61h0"></path><path d="M118 61h10"></path><g><path d="M128 61h0"></path><path d="M220 61h0"></path><rect x="128" y="50" width="92" height="22"></rect><text x="174" y="65">hex digit</text></g><path d="M220 61h10"></path><path d="M128 61a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M128 91h9.5"></path><path d="M210.5 91h9.5"></path><text x="174" y="96" class="comment">1-6 times</text></g><path d="M220 91a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M230 61h10"></path><g><path d="M240 61h0"></path><path d="M316 61h0"></path><path d="M240 61h20"></path><g><path d="M260 61h36"></path></g><path d="M296 61h20"></path><path d="M240 61a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M260 81h0"></path><path d="M296 81h0"></path><rect x="260" y="70" width="36" height="22"></rect><text x="278" y="85">WS</text></g><path d="M296 81a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g></g><path d="M316 61a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><path d="M 336 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="ident-diagram">IDENT</dt>
<dd><svg class="railroad-diagram" width="729" height="110"><g transform="translate(.5 .5)"><path d="M 20 31 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><g><path d="M40 41h0"></path><path d="M108 41h0"></path><path d="M40 41h20"></path><g><path d="M60 41h28"></path></g><path d="M88 41h20"></path><path d="M40 41a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M60 61h0"></path><path d="M88 61h0"></path><rect x="60" y="50" width="28" height="22" rx="10" ry="10"></rect><text x="74" y="65">-</text></g><path d="M88 61a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g><g><path d="M108 41h0"></path><path d="M344 41h0"></path><path d="M108 41h20"></path><g><path d="M128 41h0"></path><path d="M324 41h0"></path><rect x="128" y="30" width="196" height="22"></rect><text x="226" y="45">a-z A-Z _ or non-ASCII</text></g><path d="M324 41h20"></path><path d="M108 41a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M128 71h64"></path><path d="M260 71h64"></path><rect x="192" y="60" width="68" height="22"></rect><text x="226" y="75">escape</text></g><path d="M324 71a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><g><path d="M344 41h0"></path><path d="M688 41h0"></path><path d="M344 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M364 21h304"></path></g><path d="M668 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M344 41h20"></path><g><path d="M364 41h0"></path><path d="M668 41h0"></path><path d="M364 41h10"></path><g><path d="M374 41h0"></path><path d="M658 41h0"></path><path d="M374 41h20"></path><g><path d="M394 41h0"></path><path d="M638 41h0"></path><rect x="394" y="30" width="244" height="22"></rect><text x="516" y="45">a-z A-Z 0-9 _ - or non-ASCII</text></g><path d="M638 41h20"></path><path d="M374 41a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M394 71h88"></path><path d="M550 71h88"></path><rect x="482" y="60" width="68" height="22"></rect><text x="516" y="75">escape</text></g><path d="M638 71a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><path d="M658 41h10"></path><path d="M374 41a10 10 0 0 0 -10 10v29a10 10 0 0 0 10 10"></path><g><path d="M374 90h284"></path></g><path d="M658 90a10 10 0 0 0 10 -10v-29a10 10 0 0 0 -10 -10"></path></g><path d="M668 41h20"></path></g><path d="M 688 41 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="function-diagram">FUNCTION</dt>
<dd><svg class="railroad-diagram" width="209" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M110 31h0"></path><rect x="50" y="20" width="60" height="22"></rect><text x="80" y="35">IDENT</text></g><path d="M110 31h10"></path><path d="M120 31h10"></path><g><path d="M130 31h0"></path><path d="M158 31h0"></path><rect x="130" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="144" y="35">(</text></g><path d="M158 31h10"></path><path d="M 168 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="at-keyword-diagram">AT-KEYWORD</dt>
<dd><svg class="railroad-diagram" width="209" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M78 31h0"></path><rect x="50" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="64" y="35">@</text></g><path d="M78 31h10"></path><path d="M88 31h10"></path><g><path d="M98 31h0"></path><path d="M158 31h0"></path><rect x="98" y="20" width="60" height="22"></rect><text x="128" y="35">IDENT</text></g><path d="M158 31h10"></path><path d="M 168 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="hash-diagram">HASH</dt>
<dd><svg class="railroad-diagram" width="453" height="100"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M78 31h0"></path><rect x="50" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="64" y="35">#</text></g><path d="M78 31h10"></path><path d="M88 31h10"></path><g><path d="M98 31h0"></path><path d="M402 31h0"></path><path d="M98 31h10"></path><g><path d="M108 31h0"></path><path d="M392 31h0"></path><path d="M108 31h20"></path><g><path d="M128 31h0"></path><path d="M372 31h0"></path><rect x="128" y="20" width="244" height="22"></rect><text x="250" y="35">a-z A-Z 0-9 _ - or non-ASCII</text></g><path d="M372 31h20"></path><path d="M108 31a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M128 61h88"></path><path d="M284 61h88"></path><rect x="216" y="50" width="68" height="22"></rect><text x="250" y="65">escape</text></g><path d="M372 61a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><path d="M392 31h10"></path><path d="M108 31a10 10 0 0 0 -10 10v29a10 10 0 0 0 10 10"></path><g><path d="M108 80h284"></path></g><path d="M392 80a10 10 0 0 0 10 -10v-29a10 10 0 0 0 -10 -10"></path></g><path d="M402 31h10"></path><path d="M 412 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="string-diagram">STRING</dt>
<dd><svg class="railroad-diagram" width="441" height="248"><g transform="translate(.5 .5)"><path d="M 20 31 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><g><path d="M40 41h0"></path><path d="M400 41h0"></path><path d="M40 41h20"></path><g><path d="M60 41h0"></path><path d="M380 41h0"></path><path d="M60 41h10"></path><g><path d="M70 41h0"></path><path d="M98 41h0"></path><rect x="70" y="30" width="28" height="22" rx="10" ry="10"></rect><text x="84" y="45">"</text></g><path d="M98 41h10"></path><g><path d="M108 41h0"></path><path d="M332 41h0"></path><path d="M108 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M128 21h184"></path></g><path d="M312 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M108 41h20"></path><g><path d="M128 41h0"></path><path d="M312 41h0"></path><path d="M128 41h10"></path><g><path d="M138 41h0"></path><path d="M302 41h0"></path><path d="M138 41h20"></path><g><path d="M158 41h0"></path><path d="M282 41h0"></path><rect x="158" y="30" width="124" height="22"></rect><text x="220" y="45">not " \ or NL</text></g><path d="M282 41h20"></path><path d="M138 41a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M158 71h28"></path><path d="M254 71h28"></path><rect x="186" y="60" width="68" height="22"></rect><text x="220" y="75">escape</text></g><path d="M282 71a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path><path d="M138 41a10 10 0 0 1 10 10v40a10 10 0 0 0 10 10"></path><g><path d="M158 101h10"></path><path d="M272 101h10"></path><path d="M168 101h10"></path><g><path d="M178 101h0"></path><path d="M206 101h0"></path><rect x="178" y="90" width="28" height="22" rx="10" ry="10"></rect><text x="192" y="105">\</text></g><path d="M206 101h10"></path><path d="M216 101h10"></path><g><path d="M226 101h0"></path><path d="M262 101h0"></path><rect x="226" y="90" width="36" height="22"></rect><text x="244" y="105">NL</text></g><path d="M262 101h10"></path></g><path d="M282 101a10 10 0 0 0 10 -10v-40a10 10 0 0 1 10 -10"></path></g><path d="M302 41h10"></path><path d="M138 41a10 10 0 0 0 -10 10v59a10 10 0 0 0 10 10"></path><g><path d="M138 120h164"></path></g><path d="M302 120a10 10 0 0 0 10 -10v-59a10 10 0 0 0 -10 -10"></path></g><path d="M312 41h20"></path></g><path d="M332 41h10"></path><g><path d="M342 41h0"></path><path d="M370 41h0"></path><rect x="342" y="30" width="28" height="22" rx="10" ry="10"></rect><text x="356" y="45">"</text></g><path d="M370 41h10"></path></g><path d="M380 41h20"></path><path d="M40 41a10 10 0 0 1 10 10v88a10 10 0 0 0 10 10"></path><g><path d="M60 149h0"></path><path d="M380 149h0"></path><path d="M60 149h10"></path><g><path d="M70 149h0"></path><path d="M98 149h0"></path><rect x="70" y="138" width="28" height="22" rx="10" ry="10"></rect><text x="84" y="153">'</text></g><path d="M98 149h10"></path><g><path d="M108 149h0"></path><path d="M332 149h0"></path><path d="M108 149a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M128 129h184"></path></g><path d="M312 129a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M108 149h20"></path><g><path d="M128 149h0"></path><path d="M312 149h0"></path><path d="M128 149h10"></path><g><path d="M138 149h0"></path><path d="M302 149h0"></path><path d="M138 149h20"></path><g><path d="M158 149h0"></path><path d="M282 149h0"></path><rect x="158" y="138" width="124" height="22"></rect><text x="220" y="153">not ' \ or NL</text></g><path d="M282 149h20"></path><path d="M138 149a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M158 179h28"></path><path d="M254 179h28"></path><rect x="186" y="168" width="68" height="22"></rect><text x="220" y="183">escape</text></g><path d="M282 179a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path><path d="M138 149a10 10 0 0 1 10 10v40a10 10 0 0 0 10 10"></path><g><path d="M158 209h10"></path><path d="M272 209h10"></path><path d="M168 209h10"></path><g><path d="M178 209h0"></path><path d="M206 209h0"></path><rect x="178" y="198" width="28" height="22" rx="10" ry="10"></rect><text x="192" y="213">\</text></g><path d="M206 209h10"></path><path d="M216 209h10"></path><g><path d="M226 209h0"></path><path d="M262 209h0"></path><rect x="226" y="198" width="36" height="22"></rect><text x="244" y="213">NL</text></g><path d="M262 209h10"></path></g><path d="M282 209a10 10 0 0 0 10 -10v-40a10 10 0 0 1 10 -10"></path></g><path d="M302 149h10"></path><path d="M138 149a10 10 0 0 0 -10 10v59a10 10 0 0 0 10 10"></path><g><path d="M138 228h164"></path></g><path d="M302 228a10 10 0 0 0 10 -10v-59a10 10 0 0 0 -10 -10"></path></g><path d="M312 149h20"></path></g><path d="M332 149h10"></path><g><path d="M342 149h0"></path><path d="M370 149h0"></path><rect x="342" y="138" width="28" height="22" rx="10" ry="10"></rect><text x="356" y="153">'</text></g><path d="M370 149h10"></path></g><path d="M380 149a10 10 0 0 0 10 -10v-88a10 10 0 0 1 10 -10"></path></g><path d="M 400 41 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="url-diagram">URL</dt>
<dd><svg class="railroad-diagram" width="813" height="178"><g transform="translate(.5 .5)"><path d="M 20 99 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 109h10"></path><g><path d="M50 109h0"></path><path d="M150 109h0"></path><rect x="50" y="98" width="100" height="22"></rect><text x="100" y="113">IDENT(url)</text></g><path d="M150 109h10"></path><path d="M160 109h10"></path><g><path d="M170 109h0"></path><path d="M198 109h0"></path><rect x="170" y="98" width="28" height="22" rx="10" ry="10"></rect><text x="184" y="113">(</text></g><path d="M198 109h10"></path><g><path d="M208 109h0"></path><path d="M724 109h0"></path><path d="M208 109a10 10 0 0 0 10 -10v-48a10 10 0 0 1 10 -10"></path><g><path d="M228 41h88"></path><path d="M616 41h88"></path><g><path d="M316 41h0"></path><path d="M412 41h0"></path><path d="M316 41h20"></path><g><path d="M336 41h56"></path></g><path d="M392 41h20"></path><path d="M316 41a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M336 61h0"></path><path d="M392 61h0"></path><path d="M336 61h10"></path><g><path d="M346 61h0"></path><path d="M382 61h0"></path><rect x="346" y="50" width="36" height="22"></rect><text x="364" y="65">WS</text></g><path d="M382 61h10"></path><path d="M346 61a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M346 81h36"></path></g><path d="M382 81a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M392 61a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g><g><path d="M412 41h0"></path><path d="M520 41h0"></path><path d="M412 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M432 21h68"></path></g><path d="M500 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M412 41h20"></path><g><path d="M432 41h0"></path><path d="M500 41h0"></path><rect x="432" y="30" width="68" height="22"></rect><text x="466" y="45">STRING</text></g><path d="M500 41h20"></path></g><g><path d="M520 41h0"></path><path d="M616 41h0"></path><path d="M520 41h20"></path><g><path d="M540 41h56"></path></g><path d="M596 41h20"></path><path d="M520 41a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M540 61h0"></path><path d="M596 61h0"></path><path d="M540 61h10"></path><g><path d="M550 61h0"></path><path d="M586 61h0"></path><rect x="550" y="50" width="36" height="22"></rect><text x="568" y="65">WS</text></g><path d="M586 61h10"></path><path d="M550 61a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M550 81h36"></path></g><path d="M586 81a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M596 61a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g></g><path d="M704 41a10 10 0 0 1 10 10v48a10 10 0 0 0 10 10"></path><path d="M208 109h20"></path><g><path d="M228 109h0"></path><path d="M704 109h0"></path><g><path d="M228 109h0"></path><path d="M324 109h0"></path><path d="M228 109h20"></path><g><path d="M248 109h56"></path></g><path d="M304 109h20"></path><path d="M228 109a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M248 129h0"></path><path d="M304 129h0"></path><path d="M248 129h10"></path><g><path d="M258 129h0"></path><path d="M294 129h0"></path><rect x="258" y="118" width="36" height="22"></rect><text x="276" y="133">WS</text></g><path d="M294 129h10"></path><path d="M258 129a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M258 149h36"></path></g><path d="M294 149a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M304 129a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g><path d="M324 109h10"></path><g><path d="M334 109h0"></path><path d="M598 109h0"></path><path d="M334 109h10"></path><g><path d="M344 109h0"></path><path d="M588 109h0"></path><path d="M344 109h20"></path><g><path d="M364 109h0"></path><path d="M568 109h0"></path><rect x="364" y="98" width="204" height="22"></rect><text x="466" y="113">not " ' ( ) \ WS or NPC</text></g><path d="M568 109h20"></path><path d="M344 109a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M364 139h68"></path><path d="M500 139h68"></path><rect x="432" y="128" width="68" height="22"></rect><text x="466" y="143">escape</text></g><path d="M568 139a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><path d="M588 109h10"></path><path d="M344 109a10 10 0 0 0 -10 10v29a10 10 0 0 0 10 10"></path><g><path d="M344 158h244"></path></g><path d="M588 158a10 10 0 0 0 10 -10v-29a10 10 0 0 0 -10 -10"></path></g><path d="M598 109h10"></path><g><path d="M608 109h0"></path><path d="M704 109h0"></path><path d="M608 109h20"></path><g><path d="M628 109h56"></path></g><path d="M684 109h20"></path><path d="M608 109a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M628 129h0"></path><path d="M684 129h0"></path><path d="M628 129h10"></path><g><path d="M638 129h0"></path><path d="M674 129h0"></path><rect x="638" y="118" width="36" height="22"></rect><text x="656" y="133">WS</text></g><path d="M674 129h10"></path><path d="M638 129a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M638 149h36"></path></g><path d="M674 149a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M684 129a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g></g><path d="M704 109h20"></path></g><path d="M724 109h10"></path><g><path d="M734 109h0"></path><path d="M762 109h0"></path><rect x="734" y="98" width="28" height="22" rx="10" ry="10"></rect><text x="748" y="113">)</text></g><path d="M762 109h10"></path><path d="M 772 109 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="number-diagram">NUMBER</dt>
<dd><svg class="railroad-diagram" width="713" height="179"><g transform="translate(.5 .5)"><path d="M 20 50 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><g><path d="M40 60h0"></path><path d="M108 60h0"></path><path d="M40 60a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M60 40h0"></path><path d="M88 40h0"></path><rect x="60" y="29" width="28" height="22" rx="10" ry="10"></rect><text x="74" y="44">+</text></g><path d="M88 40a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M40 60h20"></path><g><path d="M60 60h28"></path></g><path d="M88 60h20"></path><path d="M40 60a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M60 80h0"></path><path d="M88 80h0"></path><rect x="60" y="69" width="28" height="22" rx="10" ry="10"></rect><text x="74" y="84">-</text></g><path d="M88 80a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g><g><path d="M108 60h0"></path><path d="M396 60h0"></path><path d="M108 60h20"></path><g><path d="M128 60h0"></path><path d="M376 60h0"></path><path d="M128 60h10"></path><g><path d="M138 60h0"></path><path d="M218 60h0"></path><path d="M138 60h10"></path><g><path d="M148 60h0"></path><path d="M208 60h0"></path><rect x="148" y="49" width="60" height="22"></rect><text x="178" y="64">digit</text></g><path d="M208 60h10"></path><path d="M148 60a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M148 80h60"></path></g><path d="M208 80a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M218 60h10"></path><path d="M228 60h10"></path><g><path d="M238 60h0"></path><path d="M266 60h0"></path><rect x="238" y="49" width="28" height="22" rx="10" ry="10"></rect><text x="252" y="64">.</text></g><path d="M266 60h10"></path><path d="M276 60h10"></path><g><path d="M286 60h0"></path><path d="M366 60h0"></path><path d="M286 60h10"></path><g><path d="M296 60h0"></path><path d="M356 60h0"></path><rect x="296" y="49" width="60" height="22"></rect><text x="326" y="64">digit</text></g><path d="M356 60h10"></path><path d="M296 60a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M296 80h60"></path></g><path d="M356 80a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M366 60h10"></path></g><path d="M376 60h20"></path><path d="M108 60a10 10 0 0 1 10 10v19a10 10 0 0 0 10 10"></path><g><path d="M128 99h84"></path><path d="M292 99h84"></path><path d="M212 99h10"></path><g><path d="M222 99h0"></path><path d="M282 99h0"></path><rect x="222" y="88" width="60" height="22"></rect><text x="252" y="103">digit</text></g><path d="M282 99h10"></path><path d="M222 99a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M222 119h60"></path></g><path d="M282 119a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M376 99a10 10 0 0 0 10 -10v-19a10 10 0 0 1 10 -10"></path><path d="M108 60a10 10 0 0 1 10 10v58a10 10 0 0 0 10 10"></path><g><path d="M128 138h50"></path><path d="M326 138h50"></path><path d="M178 138h10"></path><g><path d="M188 138h0"></path><path d="M216 138h0"></path><rect x="188" y="127" width="28" height="22" rx="10" ry="10"></rect><text x="202" y="142">.</text></g><path d="M216 138h10"></path><path d="M226 138h10"></path><g><path d="M236 138h0"></path><path d="M316 138h0"></path><path d="M236 138h10"></path><g><path d="M246 138h0"></path><path d="M306 138h0"></path><rect x="246" y="127" width="60" height="22"></rect><text x="276" y="142">digit</text></g><path d="M306 138h10"></path><path d="M246 138a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M246 158h60"></path></g><path d="M306 158a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M316 138h10"></path></g><path d="M376 138a10 10 0 0 0 10 -10v-58a10 10 0 0 1 10 -10"></path></g><g><path d="M396 60h0"></path><path d="M672 60h0"></path><path d="M396 60h20"></path><g><path d="M416 60h236"></path></g><path d="M652 60h20"></path><path d="M396 60a10 10 0 0 1 10 10v28a10 10 0 0 0 10 10"></path><g><path d="M416 108h0"></path><path d="M652 108h0"></path><g><path d="M416 108h0"></path><path d="M484 108h0"></path><path d="M416 108h20"></path><g><path d="M436 108h0"></path><path d="M464 108h0"></path><rect x="436" y="97" width="28" height="22" rx="10" ry="10"></rect><text x="450" y="112">e</text></g><path d="M464 108h20"></path><path d="M416 108a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M436 138h0"></path><path d="M464 138h0"></path><rect x="436" y="127" width="28" height="22" rx="10" ry="10"></rect><text x="450" y="142">E</text></g><path d="M464 138a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><g><path d="M484 108h0"></path><path d="M552 108h0"></path><path d="M484 108a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M504 88h0"></path><path d="M532 88h0"></path><rect x="504" y="77" width="28" height="22" rx="10" ry="10"></rect><text x="518" y="92">+</text></g><path d="M532 88a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M484 108h20"></path><g><path d="M504 108h28"></path></g><path d="M532 108h20"></path><path d="M484 108a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><g><path d="M504 128h0"></path><path d="M532 128h0"></path><rect x="504" y="117" width="28" height="22" rx="10" ry="10"></rect><text x="518" y="132">-</text></g><path d="M532 128a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path></g><path d="M552 108h10"></path><g><path d="M562 108h0"></path><path d="M642 108h0"></path><path d="M562 108h10"></path><g><path d="M572 108h0"></path><path d="M632 108h0"></path><rect x="572" y="97" width="60" height="22"></rect><text x="602" y="112">digit</text></g><path d="M632 108h10"></path><path d="M572 108a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M572 128h60"></path></g><path d="M632 128a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M642 108h10"></path></g><path d="M652 108a10 10 0 0 0 10 -10v-28a10 10 0 0 1 10 -10"></path></g><path d="M 672 60 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="dimension-diagram">DIMENSION</dt>
<dd><svg class="railroad-diagram" width="249" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M118 31h0"></path><rect x="50" y="20" width="68" height="22"></rect><text x="84" y="35">NUMBER</text></g><path d="M118 31h10"></path><path d="M128 31h10"></path><g><path d="M138 31h0"></path><path d="M198 31h0"></path><rect x="138" y="20" width="60" height="22"></rect><text x="168" y="35">IDENT</text></g><path d="M198 31h10"></path><path d="M 208 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="percentage-diagram">PERCENTAGE</dt>
<dd><svg class="railroad-diagram" width="217" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M118 31h0"></path><rect x="50" y="20" width="68" height="22"></rect><text x="84" y="35">NUMBER</text></g><path d="M118 31h10"></path><path d="M128 31h10"></path><g><path d="M138 31h0"></path><path d="M166 31h0"></path><rect x="138" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="152" y="35">%</text></g><path d="M166 31h10"></path><path d="M 176 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="unicode-range-diagram">UNICODE-RANGE</dt>
<dd><svg class="railroad-diagram" width="600" height="222"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><g><path d="M40 31h0"></path><path d="M108 31h0"></path><path d="M40 31h20"></path><g><path d="M60 31h0"></path><path d="M88 31h0"></path><rect x="60" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="74" y="35">U</text></g><path d="M88 31h20"></path><path d="M40 31a10 10 0 0 1 10 10v10a10 10 0 0 0 10 10"></path><g><path d="M60 61h0"></path><path d="M88 61h0"></path><rect x="60" y="50" width="28" height="22" rx="10" ry="10"></rect><text x="74" y="65">u</text></g><path d="M88 61a10 10 0 0 0 10 -10v-10a10 10 0 0 1 10 -10"></path></g><path d="M108 31h10"></path><g><path d="M118 31h0"></path><path d="M146 31h0"></path><rect x="118" y="20" width="28" height="22" rx="10" ry="10"></rect><text x="132" y="35">+</text></g><path d="M146 31h10"></path><g><path d="M156 31h0"></path><path d="M559 31h0"></path><path d="M156 31h20"></path><g><path d="M176 31h115.5"></path><path d="M423.5 31h115.5"></path><path d="M291.5 31h10"></path><g><path d="M301.5 31h0"></path><path d="M413.5 31h0"></path><path d="M301.5 31h10"></path><g><path d="M311.5 31h0"></path><path d="M403.5 31h0"></path><rect x="311.5" y="20" width="92" height="22"></rect><text x="357.5" y="35">hex digit</text></g><path d="M403.5 31h10"></path><path d="M311.5 31a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M311.5 61h9.5"></path><path d="M394 61h9.5"></path><text x="357.5" y="66" class="comment">1-6 times</text></g><path d="M403.5 61a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M413.5 31h10"></path></g><path d="M539 31h20"></path><path d="M156 31a10 10 0 0 1 10 10v50a10 10 0 0 0 10 10"></path><g><path d="M176 101h0"></path><path d="M539 101h0"></path><g><path d="M176 101h0"></path><path d="M328 101h0"></path><path d="M176 101a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M196 81h112"></path></g><path d="M308 81a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M176 101h20"></path><g><path d="M196 101h0"></path><path d="M308 101h0"></path><path d="M196 101h10"></path><g><path d="M206 101h0"></path><path d="M298 101h0"></path><rect x="206" y="90" width="92" height="22"></rect><text x="252" y="105">hex digit</text></g><path d="M298 101h10"></path><path d="M206 101a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M206 131h9.5"></path><path d="M288.5 131h9.5"></path><text x="252" y="136" class="comment">1-5 times</text></g><path d="M298 131a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M308 101h20"></path></g><path d="M328 101h10"></path><g><path d="M338 101h0"></path><path d="M529 101h0"></path><path d="M338 101h10"></path><g><path d="M348 101h71.5"></path><path d="M447.5 101h71.5"></path><rect x="419.5" y="90" width="28" height="22" rx="10" ry="10"></rect><text x="433.5" y="105">?</text></g><path d="M519 101h10"></path><path d="M348 101a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M348 131h0"></path><path d="M519 131h0"></path><text x="433.5" y="136" class="comment">1 to (6 - digits) times</text></g><path d="M519 131a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M529 101h10"></path></g><path d="M539 101a10 10 0 0 0 10 -10v-50a10 10 0 0 1 10 -10"></path><path d="M156 31a10 10 0 0 1 10 10v110a10 10 0 0 0 10 10"></path><g><path d="M176 161h25.5"></path><path d="M513.5 161h25.5"></path><path d="M201.5 161h10"></path><g><path d="M211.5 161h0"></path><path d="M323.5 161h0"></path><path d="M211.5 161h10"></path><g><path d="M221.5 161h0"></path><path d="M313.5 161h0"></path><rect x="221.5" y="150" width="92" height="22"></rect><text x="267.5" y="165">hex digit</text></g><path d="M313.5 161h10"></path><path d="M221.5 161a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M221.5 191h9.5"></path><path d="M304 191h9.5"></path><text x="267.5" y="196" class="comment">1-6 times</text></g><path d="M313.5 191a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M323.5 161h10"></path><path d="M333.5 161h10"></path><g><path d="M343.5 161h0"></path><path d="M371.5 161h0"></path><rect x="343.5" y="150" width="28" height="22" rx="10" ry="10"></rect><text x="357.5" y="165">-</text></g><path d="M371.5 161h10"></path><path d="M381.5 161h10"></path><g><path d="M391.5 161h0"></path><path d="M503.5 161h0"></path><path d="M391.5 161h10"></path><g><path d="M401.5 161h0"></path><path d="M493.5 161h0"></path><rect x="401.5" y="150" width="92" height="22"></rect><text x="447.5" y="165">hex digit</text></g><path d="M493.5 161h10"></path><path d="M401.5 161a10 10 0 0 0 -10 10v10a10 10 0 0 0 10 10"></path><g><path d="M401.5 191h9.5"></path><path d="M484 191h9.5"></path><text x="447.5" y="196" class="comment">1-6 times</text></g><path d="M493.5 191a10 10 0 0 0 10 -10v-10a10 10 0 0 0 -10 -10"></path></g><path d="M503.5 161h10"></path></g><path d="M539 161a10 10 0 0 0 10 -10v-110a10 10 0 0 1 10 -10"></path></g><path d="M 559 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="comment-diagram">COMMENT</dt>
<dd><svg class="railroad-diagram" width="497" height="81"><g transform="translate(.5 .5)"><path d="M 20 31 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 41h10"></path><g><path d="M50 41h0"></path><path d="M86 41h0"></path><rect x="50" y="30" width="36" height="22" rx="10" ry="10"></rect><text x="68" y="45">/*</text></g><path d="M86 41h10"></path><g><path d="M96 41h0"></path><path d="M400 41h0"></path><path d="M96 41a10 10 0 0 0 10 -10v0a10 10 0 0 1 10 -10"></path><g><path d="M116 21h264"></path></g><path d="M380 21a10 10 0 0 1 10 10v0a10 10 0 0 0 10 10"></path><path d="M96 41h20"></path><g><path d="M116 41h0"></path><path d="M380 41h0"></path><path d="M116 41h10"></path><g><path d="M126 41h0"></path><path d="M370 41h0"></path><rect x="126" y="30" width="244" height="22"></rect><text x="248" y="45">anything but * followed by /</text></g><path d="M370 41h10"></path><path d="M126 41a10 10 0 0 0 -10 10v0a10 10 0 0 0 10 10"></path><g><path d="M126 61h244"></path></g><path d="M370 61a10 10 0 0 0 10 -10v0a10 10 0 0 0 -10 -10"></path></g><path d="M380 41h20"></path></g><path d="M400 41h10"></path><g><path d="M410 41h0"></path><path d="M446 41h0"></path><rect x="410" y="30" width="36" height="22" rx="10" ry="10"></rect><text x="428" y="45">*/</text></g><path d="M446 41h10"></path><path d="M 456 41 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="cdo-diagram">CDO</dt>
<dd><svg class="railroad-diagram" width="153" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M102 31h0"></path><rect x="50" y="20" width="52" height="22" rx="10" ry="10"></rect><text x="76" y="35"><!--</text></g><path d="M102 31h10"></path><path d="M 112 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
<dt id="cdc-diagram">CDC</dt>
<dd><svg class="railroad-diagram" width="145" height="62"><g transform="translate(.5 .5)"><path d="M 20 21 v 20 m 10 -20 v 20 m -10 -10 h 20.5"></path><path d="M40 31h10"></path><g><path d="M50 31h0"></path><path d="M94 31h0"></path><rect x="50" y="20" width="44" height="22" rx="10" ry="10"></rect><text x="72" y="35">--></text></g><path d="M94 31h10"></path><path d="M 104 31 h 20 m -10 -10 v 20 m 10 -20 v 20"></path></g></svg></dd>
</dl>
<h3>
Tokenizer Flags</h3>
<p>
The tokenizer can be run with any of several flags that alter its behavior.
<dl>
<dt>the <dfn>transform function whitespace</dfn> flag
<dd>
This flag is set when parsing SVG's <code>transform</code> attribute.
When this is set, whitespace is allowed between the name of a transform function and its opening parenthesis.
</dl>
<h3>
Definitions</h3>
<p>
This section defines several terms used during the tokenization phase.
<dl>
<dt><dfn>digit</dfn>
<dd>
A character between U+0030 DIGIT ZERO (0) and U+0039 DIGIT NINE (9).
<dt><dfn>hex digit</dfn>
<dd>
A <i>digit</i>,
or a character between U+0041 LATIN CAPITAL LETTER A (A) and U+0046 LATIN CAPITAL LETTER F (F),
or a character between U+0061 LATIN SMALL LETTER A (a) and U+0066 LATIN SMALL LETTER F (f).
<dt><dfn>uppercase letter</dfn>
<dd>
A character between U+0041 LATIN CAPITAL LETTER A (A) and U+005A LATIN CAPITAL LETTER Z (Z).
<dt><dfn>lowercase letter</dfn>
<dd>
A character between U+0061 LATIN SMALL LETTER A (a) and U+007A LATIN SMALL LETTER Z (z).
<dt><dfn>letter</dfn>
<dd>
An <i>uppercase letter</i>
or a <i>lowercase letter</i>.
<dt><dfn>non-ASCII character</dfn>
<dd>
A character with a codepoint equal to or greater than U+0080 <control>.
<dt><dfn>name-start character</dfn>
<dd>
A <i>letter</i>,
a <i>non-ASCII character</i>,
or U+005F LOW LINE (_).
<dt><dfn>name character</dfn>
<dd>
A <i>name-start character</i>,
A <i>digit</i>,
or U+002D HYPHEN-MINUS (-).
<dt><dfn>non-printable character</dfn>
<dd>
A character between U+0000 NULL and U+0008 BACKSPACE
or a character between U+000E SHIFT OUT and U+001F INFORMATION SEPARATOR ONE
or a character between U+007F DELETE and U+009F APPLICATION PROGRAM COMMAND.
<dt><dfn>newline</dfn>
<dd>
U+000A LINE FEED or U+000C FORM FEED.
<span class='note'>
Note that U+000D CARRIAGE RETURN is not included in this definition,
as it is removed from the stream during preprocessing.
</span>
<dt><dfn>whitespace</dfn>
<dd>A <i>newline</i>, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
<dt><dfn>maximum allowed codepoint</dfn>
<dd>The greatest codepoint defined by Unicode. This is currently U+10FFFF.
</dl>
<h3>
Tokenizer State Machine</h3>
<h4>
<dfn>Data state</dfn></h4>
<p>
Consume the <i>next input character</i>.
<dl>
<dt><i>whitespace</i>
<dd>
Consume as much <i>whitespace</i> as possible.
Emit a whitespace token.
Remain in this state.
<dt>U+0022 QUOTATION MARK (")
<dd>
Switch to the <i>double-quote-string state</i>.
<dt>U+0023 NUMBER SIGN (#)
<dd>
Switch to the <i>hash state</i>.
<dt>U+0024 DOLLAR SIGN ($)
<dd>
If the <i>next input character</i> is
U+003D EQUALS SIGN (=),
consume it
and emit a suffix-match token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
<dt>U+0027 APOSTROPHE (')
<dd>
Switch to the <i>single-quote-string state</i>.
<dt>U+0028 LEFT PARENTHESIS (()
<dd>
Emit a ( token.
Remain in this state.
<dt>U+0029 RIGHT PARENTHESIS ())
<dd>
Emit a ) token.
Remain in this state.
<dt>U+002A ASTERISK (*)
<dd>
If the <i>next input character</i> is
U+003D EQUALS SIGN (=),
consume it
and emit a substring-match token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
<dt>U+002B PLUS SIGN (+)
<dd>
If the <i>next input character</i> is
a <i>digit</i>,
or the <i title="next input character">next 2 input characters</i> are
U+002E FULL STOP (.)
followed by a <i>digit</i>,
switch to the <i>number state</i>.
Reconsume the <i>current input character</i>.
<p>
Otherwise,
emit a delim token
with its value set to U+002B PLUS SIGN (+).
Remain in this state.
<dt>U+002D HYPHEN-MINUS (-)
<dd>
If the <i title="next input character">next 2 input characters</i> are
U+002D HYPHEN-MINUS
U+003E GREATER-THAN SIGN
(->),
consume them,
emit a CDC token,
and remain in this state.
<p>
Otherwise,
if the <i>next input character</i> is a <i>digit</i>,
or the <i title="next input character">next 2 input characters</i> are
U+002E FULL STOP (.)
followed by a <i>digit</i>,
switch to the <i>number state</i>.
Reconsume the <i>current input character</i>.
<p>
Otherwise,
switch to the <i>ident state</i>.
Reconsume the <i>current input character</i>.
<dt>U+002E FULL STOP (.)
<dd>
If the <i>next input character</i> is a <i>digit</i>,
switch to the <i>number state</i>.
Reconsume the <i>current input character</i>.
<p>
Otherwise,
emit a delim token
with its value set to U+002E FULL STOP (.).
Remain in this state.
<dt>U+002F SOLIDUS (/)
<dd>
If the <i>next input character</i> is U+002A ASTERISK (*),
consume it
and switch to the <i>comment state</i>.
<p>
Otherwise,
emit a delim token
with its value set to U+002F SOLIDUS (/).
Remain in this state.
<dt>U+003A COLON (:)
<dd>
Emit a colon token.
Remain in this state.
<dt>U+003B SEMICOLON (;)
<dd>
Emit a semicolon token.
Remain in this state.
<dt>U+003C LESS-THAN SIGN (<)
<dd>
If the <i title="next input character">next 3 input characters</i> are
U+0021 EXCLAMATION MARK
U+002D HYPHEN-MINUS
U+002D HYPHEN-MINUS
(!--),
consume them
and emit a cdo token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to U+003C LESS-THAN SIGN (<).
Remain in this state.
<dt>U+0040 COMMERCIAL AT (@)
<dd>
Switch to the <i>at-keyword state</i>.
<dt>U+005B LEFT SQUARE BRACKET ([)
<dd>
Emit a [ token.
Remain in this state.
<dt>U+005C REVERSE SOLIDUS (\)
<dd>
If the <i>next input character</i> is
a <i>newline</i>
or EOF,
this is a <i>parse error</i>.
Emit a delim token
with its value set to U+005C REVERSE SOLIDUS (\).
Remain in this state.
<p>
Otherwise, switch to the <i>ident state</i>.
Reconsume the <i>current input character</i>.
<dt>U+005D RIGHT SQUARE BRACKET (])
<dd>
Emit a ] token.
Remain in this state.
<dt>U+005E CIRCUMFLEX ACCENT (^)
<dd>
If the <i>next input character</i> is
U+003D EQUALS SIGN (=),
consume it
and emit a prefix-match token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
<dt>U+007B LEFT CURLY BRACKET ({)
<dd>
Emit a { token.
Remain in this state.
<dt>U+007D RIGHT CURLY BRACKET (})
<dd>
Emit a } token.
Remain in this state.
<dt><i>digit</i>
<dd>
Switch to the <i>number state</i>.
Reconsume the <i>current input character</i>.
<dt>U+0055 LATIN CAPITAL LETTER U (U)
<dt>U+0075 LATIN SMALL LETTER U (u)
<dd>
If the <i title="next input character">next 2 input character</i> are
U+002B PLUS SIGN (+)
followed by a <i>hex digit</i>
or U+003F QUESTION MARK (?),
consume the <i>next input character</i>.
<span class='note'>Note: don't consume both of them.</span>
Switch to the <i>unicode-range state</i>.
<p>Otherwise,
switch to the <i>ident state</i>.
Reconsume the <i>current input character</i>.
<dt><i>name-start character</i>
<dd>
Switch to the <i>ident state</i>.
Reconsume the <i>current input character</i>.
<dt>U+007C VERTICAL LINE (|)
<dd>
If the <i>next input character</i> is
U+003D EQUALS SIGN (=),
consume it
and emit a dash-match token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
<dt>U+007E TILDE (~)
<dd>
If the <i>next input character</i> is
U+003D EQUALS SIGN (=),
consume it
and emit an includes-match token.
Remain in this state.
<p>
Otherwise,
emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
<dt>EOF
<dd>
Emit an end-of-file token.
<dt>anything else
<dd>
Emit a delim token
with its value set to the <i>current input character</i>.
Remain in this state.
</dl>
<h4>
<dfn>Double-quote-string state</dfn></h4>
<p>
If a string token has not yet been created since entering this state,
create a string token
with its value initially set to the empty string.
<p>
Consume the <i>next input character</i>.
<dl>
<dt>U+0022 QUOTATION MARK (")
<dd>
Emit the string token.
Return to the <i>data state</i>.
<dt>EOF
<dd>
This is a <i>parse error</i>.
Emit the string token.
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
<dt><i>newline</i>
<dd>
This is a <i>parse error</i>.
Emit a bad-string token.
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
<dt>U+005C REVERSE SOLIDUS (\)
<dd>
If the <i>next input character</i>
is an EOF,
this is a <i>parse error</i>.
Emit a bad-string token,
then switch to the <i>data state</i>.
<p>
Otherwise,
if the <i>next input character</i> is
a <i>newline</i>,
consume it.
Remain in this state.
<p>
Otherwise,
<i>consume an escaped character</i>.
Append the returned character to the string token's value.
Remain in this state.
<dt>anything else
<dd>
Append the <i>current input character</i>
to the string token's value.
Remain in this state.
</dl>
<h4>
<dfn>Single-quote-string state</dfn></h4>
<p>
If a string token has not yet been created since entering this state,
create a string token
with its value initially set to the empty string.
<p>
Consume the <i>next input character</i>.
<dl>
<dt>U+0027 APOSTROPHE (')
<dd>
Emit the string token.
Return to the <i>data state</i>.
<dt>EOF
<dd>
This is a <i>parse error</i>.
Emit the string token.
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
<dt><i>newline</i>
<dd>
This is a <i>parse error</i>.
Emit a bad-string token.
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
<dt>U+005C REVERSE SOLIDUS (\)
<dd>
If the <i>next input character</i>
is an EOF,
this is a <i>parse error</i>.
Emit a bad-string token,
then switch to the <i>data state</i>.
<p>
Otherwise,
if the <i>next input character</i> is
a <i>newline</i>,
consume it.
Remain in this state.
<p>
Otherwise,
<i>consume an escaped character</i>.
Append the returned character to the string token's value.
Remain in this state.
<dt>anything else
<dd>
Append the <i>current input character</i>
to the string token's value.
Remain in this state.
</dl>
<h4>
<dfn>Hash state</dfn></h4>
<p>
Consume the <i>next input character</i>.
<dl>
<dt><i>name character</i>
<dd>
Create a hash token
with its value set to the <i>current input character</i>.
Switch to the <i>hash-rest state</i>.
<dt>U+005C REVERSE SOLIDUS (\)
<dd>
If the <i>next input character</i> is
a <i>newline</i> or EOF,
emit a delim token
with its value set to U+0023 NUMBER SIGN (#).
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
<p>
Otherwise,
<i>consume an escaped character</i>.
Create a hash token
with its value set to the returned character.
Switch to the <i>hash-rest state</i>.
<dt>anything else
<dd>
Emit a delim token
with its value set to U+0023 NUMBER SIGN (#).
Switch to the <i>data state</i>.
Reconsume the <i>current input character</i>.
</dl>
<h4>
<dfn>Hash-rest state</dfn></h4>
<p>
Consume the <i>next input character</i>.
<dl>
<dt><i>name character</i>
<dd>
Append the <i>current input character</i>