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Various errata #11

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Feb 13, 2023
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Various errata #11

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67a86ee
Reference terms from RDF Concepts.
gkellogg Feb 10, 2023
39b2b07
Add canonical form of N-Quads.
gkellogg Feb 10, 2023
1976817
Add missing content to quad reference.
gkellogg Feb 10, 2023
eef7226
Add grammar updates for white space and comments.
gkellogg Feb 11, 2023
99260d2
Mirror other changes from N-Triples.
gkellogg Feb 12, 2023
fe7e38b
Fix broken internal links.
gkellogg Feb 12, 2023
be52cf9
whatespace => white space.
gkellogg Feb 12, 2023
fb26365
Add requirement for final EOL.
gkellogg Feb 12, 2023
c0d3b04
Add change log entry for EOL, and remove informative comment that it …
gkellogg Feb 12, 2023
bf0616c
newlines are still optional, except for C14N
gkellogg Feb 13, 2023
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150 changes: 126 additions & 24 deletions spec/index.html
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
<!DOCTYPE html>
<html>
<html lang="en">
<head>
<title>RDF 1.2 N-Quads</title>
<meta http-equiv='Content-Type' content='text/html;charset=utf-8'/>
Expand Down Expand Up @@ -54,15 +54,15 @@
<body>

<section id='abstract'>
<p>N-Quads is a line-based, plain text format for encoding an RDF dataset.</p>
<p>N-Quads is a line-based, plain text format for encoding an <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>.</p>
</section>

<section id='sotd'>
<p>This document is part of the RDF 1.2 document suite.
The N-Quads format is a line-based RDF syntax with a similar flavor as N-Triples
[[RDF12-N-TRIPLES]]. N-Quads is a syntactic superset of N-Triples.
The N-Quads format is a line-based RDF syntax,
which is an extension of N-Triples [[RDF12-N-TRIPLES]].
The main distinction is that N-Quads allows the encoding of multiple graphs
in a single document .</p>
in a single document representing an <a data-cite="RDF12-CONCEPTS#dfn-rdf-dataset">RDF Dataset</a>.</p>

<section id="related" data-include="./common/related.html"></section>
</section>
Expand All @@ -77,10 +77,21 @@ <h2>Introduction</h2>
[[!RDF12-CONCEPTS]].
</p>

<p>N-quads statements are a sequence of RDF terms representing the subject, predicate, object and graph label
of an RDF Triple and the graph it is part of in a dataset.
<p>As with N-Triples, an N-Quads document contains no parsing directives.</p>

<p>N-Quads statements are a sequence of RDF terms representing the
<a data-cite="RDF12-CONCEPTS#dfn-subject">subject</a>,
<a data-cite="RDF12-CONCEPTS#dfn-predicate">predicate</a>, and
<a data-cite="RDF12-CONCEPTS#dfn-object">object</a>
of an <a data-cite="RDF12-CONCEPTS#dfn-rdf-triple">RDF Triple</a>
and an optional <a data-cite="RDF12-CONCEPTS#dfn-graph-name">graph name</a>
identifying a <a data-cite="RDF12-CONCEPTS#dfn-named-graph">named graph</a>
associated with the triple within an <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>,
also known as a <a data-cite="RDF12-CONCEPTS#dfn-quad">quad</a>.
These may be separated by white space (spaces <code>#x20</code> or tabs <code>#x9</code>).
This sequence is terminated by a '<code>.</code>' and a new line (optional at the end of a document).</p>
This sequence is terminated by a '<code>.</code>'
(optionaly proceded by white space),
and a new line (optional at the end of a document).</p>

<pre class="example nquads" data-transform="updateExample">
<!--
Expand All @@ -91,32 +102,60 @@ <h2>Introduction</h2>
-->
</pre>

<p>The <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a> represented by an N-Quads document contains
exactly each <a data-cite="RDF12-CONCEPTS#dfn-quad">quad</a> matching the N-Quads
<a href="#grammar-production-statement"><code>statement</code></a> production.
</p>

</section>

<section>
<h2>N-Quads Language</h2>

<p>An N-Quads document is composed of a sequence
of <a href="#simple-triples">simple statements</a>,
one for each line.
Lines consisteng entirely of white space (spaces <code>U+0020</code> or tabs <code>U+0009</code>)
and/or comments are permitted before or after each triple.</p>

<section id="simple-triples">
<h3>Simple Statements</h3>
<p>The simplest statement is a sequence of (subject, predicate, object) terms
forming an RDF triple and an optional blank node label or IRI labeling what graph
in a dataset the triple belongs to,
all are separated by whitespace and terminated by '<code>.</code>' after each statement.</p>

<p>A simple statement extends the
<a data-cite="RDF12-N-TRIPLES#simple-triples">definition of simple triple</a> in [[RDF12-N-TRIPLES]]
with an optional <a data-cite="RDF12-CONCEPTS#dfn-named-graph">named graph</a>.</p>

<p>The simplest statement is a sequence of
(<a data-cite="RDF12-CONCEPTS#dfn-subject">subject</a>,
<a data-cite="RDF12-CONCEPTS#dfn-predicate">predicate</a>,
<a data-cite="RDF12-CONCEPTS#dfn-object">object</a>) terms
forming an <a data-cite="RDF12-CONCEPTS#dfn-rdf-triple">RDF triple</a>
and an optional
<a data-cite="RDF12-CONCEPTS#dfn-graph-name">graph name</a>
(a <a data-cite="RDF12-CONCEPTS#dfn-blank-node-label">blank node label</a>
or <a data-cite="RDF12-CONCEPTS#dfn-iri">IRI</a>) labeling what
<a data-cite="RDF12-CONCEPTS#dfn-named-graph">named graph</a>
in a <a data-cite="RDF12-CONCEPTS#dfn-rdf-dataset">dataset</a> the triple belongs to,
all are separated by whitespace and terminated by '<code>.</code>' after each statement.
White space MAY occur beteween elements of this sequence.
Comments MAY occur after the terminating '<code>.</code>'.</p>

<pre class="example nquads" data-transform="updateExample">
<!--
<http://example.org/#spiderman> <http://www.perceive.net/schemas/relationship/enemyOf> <http://example.org/#green-goblin> <http://example.org/graphs/spiderman> .</script>
-->
</pre>

<p>The graph label IRI can be omitted, in which case the triples are considered
part of the default graph of the RDF dataset.<p>
<p>The <a data-cite="RDF12-CONCEPTS#dfn-graph-name">graph name</a> can be omitted, in which case the triples are considered
part of the
<a data-cite="RDF12-CONCEPTS#dfn-default-graph">default graph</a> of the <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>.<p>
</section>

<section id="sec-iri">
<h3>IRIs</h3>

<p>
<a data-cite="RDF12-CONCEPTS#iri">IRIs</a> may be written only as absolute IRIs.
As in N-Triples, <a data-cite="RDF12-CONCEPTS#iri">IRIs</a> may be written only as absolute IRIs.
IRIs are enclosed in '&lt;' and '&gt;' and may contain numeric escape sequences (described below).
For example <code>&lt;http://example.org/#green-goblin&gt;</code>.
</p>
Expand All @@ -125,7 +164,8 @@ <h3>IRIs</h3>
<section id="sec-literals">
<h3>RDF Literals</h3>

<p><a data-cite="RDF12-CONCEPTS#literal">Literals</a> are used to identify values such as strings, numbers, dates.</p>
<p>As in N-Triples,
<a data-cite="RDF12-CONCEPTS#literal">literals</a> are used to identify values such as strings, numbers, dates.</p>

<p>
Literals (Grammar production <a href="#grammar-production-literal">Literal</a>)
Expand All @@ -135,7 +175,7 @@ <h3>RDF Literals</h3>
a sequence of permitted characters or numeric escape sequence or string escape sequence,
and a final delimiter.
Literals may not contain the characters <code>"</code>,
code title="LINE FEED"><sub>LF</sub></code>,
<code title="LINE FEED"><sub>LF</sub></code>,
or <code title="CARRIAGE RETURN"><sub>CR</sub></code>.
In addition '<code>\</code>' (<span class="codepoint">U+005C</span>)
may not appear in any quoted literal except as part of an escape sequence.
Expand All @@ -152,7 +192,8 @@ <h3>RDF Literals</h3>
<section id="BNodes">
<h3>RDF Blank Nodes</h3>
<p>
<a data-cite="RDF12-CONCEPTS#blank-node">RDF blank nodes</a> in N-Quads are expressed as <code>_:</code>
As in N-Triples,
<a data-cite="RDF12-CONCEPTS#blank-node">RDF blank nodes</a> are expressed as <code>_:</code>
followed by a blank node label which is a series of name characters.
The characters in the label are built upon <a href="#grammar-production-PN_CHARS_BASE">PN_CHARS_BASE</a>,
liberalized as follows:
Expand All @@ -176,20 +217,62 @@ <h3>RDF Blank Nodes</h3>
_:bob <http://xmlns.com/foaf/0.1/knows> _:alice <http://example.org/graphs/james> .
-->
</pre>
<p class="issue" data-number="2">
Note open <a href="https://www.w3.org/2001/sw/wiki/RDF1.1_Errata#erratum_30">erratum</a> on aligning the definition and production
for blank node lables with Turtle.
</p>
</section>
</section>

<section id="canonical-quads">
<h2>A Canonical form of N-Quads</h2>
<p>This section defined a canonical form of N-Quads which has
less variability in layout. The grammar for the language is the
same. Implementers are encouraged to produce this form.</p>
<p>Canonical N-Quads has the following additional constraints on layout:</p>
<ul>
<li>The whitespace following <code>subject</code>,
<code>predicate</code>,
<code>object</code>,
and <code>graphLabel</code> if present, MUST be a single space,
(<code>U+0020</code>). All other locations that allow
whitespace MUST be empty.</li>
<li>There MUST be no comments.</li>
<li><code>HEX</code> MUST use only uppercase letters (<code>[A-F]</code>).</li>
<li>Characters MUST NOT be represented by <code>UCHAR</code>.</li>
<li>Within <a href="#grammar-production-STRING_LITERAL_QUOTE">STRING_LITERAL_QUOTE</a>,
only the characters
<code>U+0022</code>, <code>U+005C</code>, <code>U+000A</code>, <code>U+000D</code>
are encoded using <code>ECHAR</code>.
<code>ECHAR</code> MUST NOT be used for characters that are
allowed directly in
<a href="#grammar-production-STRING_LITERAL_QUOTE">STRING_LITERAL_QUOTE</a>. </li>
</ul>
<div class="issue" data-number="2">
Note open errata:
<ul>
<li><a href="https://www.w3.org/2001/sw/wiki/RDF1.1_Errata#erratum_32">32 – Issues with N-Quads/N-Triples canonicalization</a>.</li>
<li><a href="https://www.w3.org/2001/sw/wiki/RDF1.1_Errata#erratum_33">33 – Ambiguity of canonical N-Triples</a></li>
</ul>
</div>
</section>

<section id="conformance">
<p>This specification defines conformance criteria for:</p>
<ul>
<li>N-Quads documents
<li>N-Quads parsers
</ul>
<p>A conforming <strong>N-Quads document</strong> is a Unicode string that conforms to the grammar and additional constraints defined in <a href="#sec-grammar" class="sectionRef"></a>, starting with the <a href="#grammar-production-nquadsDoc"><code>nquadsDoc</code> production</a>. An N-Quad document serializes an RDF dataset.</p>
<p>A conforming <strong>N-Quads document</strong> is a Unicode string that conforms to the grammar and additional constraints defined in <a href="#sec-grammar" class="sectionRef"></a>,
starting with the <a href="#grammar-production-nquadsDoc"><code>nquadsDoc</code> production</a>.
An N-Quads document serializes an <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>.</p>

<p class="note">N-Quads documents do not provide a way of serializing empty graphs that may be part of an RDF dataset.</p>

<p>A conforming <strong>N-Quads parser</strong> is a system capable of reading N-Quads documents on behalf of an application. It makes the serialized RDF graph, as defined in <a href="#sec-parsing" class="sectionRef"></a>, available to the application, usually through some form of API.</p>
<p>A conforming <strong>N-Quads parser</strong> is a system capable of reading N-Quads documents on behalf of an application.
It makes the serialized <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>,
as defined in <a href="#sec-parsing" class="sectionRef"></a>,
available to the application, usually through some form of API.</p>

<p>The IRI that identifies the N-Quads language is: <code>http://www.w3.org/ns/formats/N-Quads</code></p>

Expand All @@ -216,10 +299,11 @@ <h3>Other Media Types</h3>
<section id="sec-grammar">
<h3>Grammar</h3>

<p>An N-Quads document is a Unicode[[!UNICODE]] character string encoded in UTF-8.
<p>An N-Quads document is a Unicode [[!UNICODE]] character string encoded in UTF-8.
Unicode code points only in the range U+0 to U+10FFFF inclusive are allowed.</p>

<p>White space (tab <code>U+0009</code> or space <code>U+0020</code>) is used to separate two terminals which would otherwise be (mis-)recognized as one terminal. White space is significant in the production <a href="#grammar-production-STRING_LITERAL_QUOTE">STRING_LITERAL_QUOTE</a>.</p>
<p>White space (tab U+0009 or space U+0020) is allowed but not required between any two terminals.
White space is significant in the production <a href="#grammar-production-STRING_LITERAL_QUOTE">STRING_LITERAL_QUOTE</a>.</p>

<p>Comments in N-Quads take the form of '<code>#</code>',
outside an <code>IRIREF</code> or <code>STRING_LITERAL_QUOTE</code>,
Expand Down Expand Up @@ -264,7 +348,17 @@ <h3>RDF Term Constructors</h3>

<section id="rdf-dataset-construction">
<h3>RDF Dataset Construction</h3>
<p>An N-Quads document defines an RDF dataset composed of RDF graphs composed of a set of RDF triples. The <code><a href="#grammar-production-statement">statement</a></code> production produces a triple defined by the terms constructed for <code><a href="#grammar-production-subject">subject</a></code>, <code><a href="#grammar-production-predicate">predicate</a></code> and <code><a href="#grammar-production-object">object</a></code>. This RDF triple is added to the graph labeled by the production <code><a href="#grammar-production-graphLabel">graphLabel</a></code>, if no <code>graphLabel</code> is present the triple is added to the RDF datasets default graph.</p>
<p>An N-Quads document defines an <a href="RDF12-CONCEPTS#dfn-rdf-dataset">RDF dataset</a>
composed of <a href="RDF12-CONCEPTS#dfn-rdf-graph">RDF graphs</a> composed of a set of
<a href="RDF12-CONCEPTS#dfn-rdf-triple">RDF triples</a>.
The <code><a href="#grammar-production-statement">statement</a></code> production produces a
triple defined by the terms constructed for
<code><a href="#grammar-production-subject">subject</a></code>,
<code><a href="#grammar-production-predicate">predicate</a></code>, and
<code><a href="#grammar-production-object">object</a></code>.
This RDF triple is added to the <a data-cite="RDF12-CONCEPTS#dfn-named-graph">graph</a> labeled by
the production <code><a href="#grammar-production-graphLabel">graphLabel</a></code>,
if no <code>graphLabel</code> is present the triple is added to the RDF dataset's default graph.</p>
</section>
</section>

Expand Down Expand Up @@ -317,7 +411,12 @@ <h2>Changes between publication as Note and RDF 1.1 Recommendation</h2>
<h2>Changes between RDF 1.1 and RDF 1.2</h2>

<ul>

<li>N-Quads is now described as a syntactic superset of [[RDF12-N-TRIPLES]].</li>
<li>Add <a href="#canonical-quads" class="sectionRef"></a> to define the canonical form of N-Quads.</li>
<li>Clarify the use of white space to separate RDF terms and the trailing `.` in a triple.
Lines composed entirely of white space and/or comments are also allowed.</li>
<li>Removed language about white space use between terminals that would otherwise
be (mis-)recognized, is this can't happen in N-Triples.</li>
</ul>
</section>

Expand Down Expand Up @@ -425,5 +524,8 @@ <h2>N-Quads Internet Media Type, File Extension and Macintosh File Type </h2>
</section>

<section id="index"></section>
<section class="appendix" id="issue-summary">
<!-- A list of issues will magically appear here -->
</section>
</body>
</html>