[16] [DFN[XPath 2.0]] は、 [[XPath]] の2つ目の版です。 [[XPath]] は [[XML]]
[[文書]]中の部分を識別したり、それらや[[数値]]等の[[データ]]の間で[[演算]]したりできる[[式言語]]です。

* 歴史

[1]
[CITE[XQuery 1.0 and XPath 2.0 Data Model]] <http://www.w3.org/2004/07/data-model-issues.html>
([[名無しさん]])

[2]
[CITE[XQuery 1.0 and XPath 2.0 Data Model]] <http://www.w3.org/2004/10/data-model-issues.html>
([[名無しさん]])

[3]
[CITE[Data Model Last Call Comments]] <http://www.w3.org/XML/2003/05/xpath-datamodel-issues/>

[5]
[CITE@EN[XML Path Language (XPath) 2.0]] ([CODE[2007-01-19 08:23:20 +09:00]] 版) <http://www.w3.org/TR/2007/REC-xpath20-20070123/>
([[名無しさん]] [WEAK[2007-01-26 17:14:05 +00:00]])

[6]
[CITE@EN[XQuery 1.0 and XPath 2.0 Functions and Operators]] ([CODE[2007-01-19 07:02:42 +09:00]] 版) <http://www.w3.org/TR/2007/REC-xpath-functions-20070123/>
([[名無しさん]] [WEAK[2007-01-27 03:27:39 +00:00]])

[7]
[CITE@en[XQuery 1.0 and XPath 2.0 Data Model (XDM)]] ([CODE[2007-01-23 07:26:51 +09:00]] 版) <http://www.w3.org/TR/2007/REC-xpath-datamodel-20070123/>
([[名無しさん]] [WEAK[2007-01-27 04:58:33 +00:00]])

[8]
[CITE@EN[XQuery 1.0 and XPath 2.0 Formal Semantics]] ([CODE[2007-01-19 07:16:26 +09:00]] 版) <http://www.w3.org/TR/2007/REC-xquery-semantics-20070123/>
([[名無しさん]] [WEAK[2007-01-27 05:39:24 +00:00]])

[9]
[CITE@EN[XQuery 1.0 and XPath 2.0 Full-Text 1.0]] ([CODE[2007-05-17 06:07:03 +09:00]] 版) <http://www.w3.org/TR/2007/WD-xpath-full-text-10-20070518/>
([[名無しさん]] [WEAK[2007-05-28 23:34:27 +00:00]])

[10]
[CITE@EN[XQuery 1.0 and XPath 2.0 Full-Text 1.0 Requirements]] ([CODE[2007-05-19 03:59:30 +09:00]] 版) <http://www.w3.org/TR/2007/WD-xpath-full-text-10-requirements-20070518/>
([[名無しさん]] [WEAK[2007-05-28 23:35:16 +00:00]])


[11]
[CITE@EN[XQuery 1.0 and XPath 2.0 Full-Text 1.0 Use Cases]] ([TIME[2007-05-19 01:02:19 +09:00]] 版) <http://www.w3.org/TR/2007/WD-xpath-full-text-10-use-cases-20070518/>
([[名無しさん]] [WEAK[2007-05-28 23:35:58 +00:00]])

[12] [CITE@EN[XML Path Language (XPath) 2.0 (Second Edition)]] ([TIME[2009-04-21 23:42:37 +09:00]] 版) <http://www.w3.org/TR/2009/PER-xpath20-20090421/>

[13] [CITE@EN[XQuery 1.0 and XPath 2.0 Formal Semantics (Second Edition)]] ([TIME[2009-04-21 10:49:07 +09:00]] 版) <http://www.w3.org/TR/2009/PER-xquery-semantics-20090421/>

[14] [CITE@EN[XQuery 1.0 and XPath 2.0 Functions and Operators (Second Edition)]] ([TIME[2009-04-18 10:18:14 +09:00]] 版) <http://www.w3.org/TR/2009/PER-xpath-functions-20090421/>

* XPath 2.0 の応用

[17] [[XSLT 2.0]] は [[XPath 2.0]] を採用しています。

[4]
[[WSDM-MUWS]] では [[XPath 1.0]] または [[XPath 2.0]]
が利用できます。

[15] [CITE@en-US[Basic XML Schema Patterns for Databinding Version 1.0]] ([TIME[2009-05-05 01:07:15 +09:00]] 版) <http://www.w3.org/TR/2009/NOTE-xmlschema-patterns-20090505/#patterns-xpath>、
[CITE@en-US[Advanced XML Schema Patterns for Databinding Version 1.0]] ([TIME[2009-05-05 01:07:15 +09:00]] 版) <http://www.w3.org/TR/2009/NOTE-xmlschema-patterns-advanced-20090505/#patterns-xpath>

[36] [[STXPath]] は [[XPath 2.0]] の変種です。

* XPath 1.0 との関係

[18] [[XPath 2.0]] は [[XPath 1.0]] の改訂版ですが、言語仕様が大幅に改訂されています。
特に、 [[XPath 1.0]] は[[弱い型付け]]の[[言語]]でしたが、 [[XPath 2.0]] は[[強い型付け]]の[[言語]]となっています。

* XQuery 1.0 との関係

[19] [[XPath 2.0]] は [[XQuery 1.0]] と協同して開発されました。両者は[[構文]]や[[意味論]]において基礎的な部分が共通しています。

* 関連

[20] [[XPath 1.0]] では [[XPointer]] での利用が主要な応用の1つとして想定されていましたが、
[[XPath 2.0]] ではそうではないようです。 [[XPointer]] 用の [[XPointer scheme]]
として [CODE(XPointerScheme)@en[[[xpath2()]]]] が定義されてはいます。

[21] [[DOM XPath]] 仕様は [[XPath 1.0]] にのみ対応しています。現時点で [[XPath 2.0]]
に対応させる動きはないようです。

[22] [CITE[XProc: An XML Pipeline Language]]
([TIME[2010-05-11 22:38:07 +09:00]] 版)
<http://www.w3.org/TR/2010/REC-xproc-20100511/#xpath-context>

[23] [CITE@en[XSLT 2.0 and XQuery 1.0 Serialization (Second Edition)]]
( ([TIME[2010-12-17 00:08:20 +09:00]] 版))
<http://www.w3.org/TR/2010/REC-xslt-xquery-serialization-20101214/#xslt20>

[24] [CITE@EN[XML Path Language (XPath) 2.0 (Second Edition)]]
( ([TIME[2011-01-05 01:25:51 +09:00]] 版))
<http://www.w3.org/TR/2010/REC-xpath20-20101214/>

[25] [CITE@en[Web Services Fragment (WS-Fragment)]]
( ([TIME[2011-12-13 17:58:12 +09:00]] 版))
<http://www.w3.org/TR/2011/REC-ws-fragment-20111213/#XPath20>

[26] [CITE@en[Web Services Eventing (WS-Eventing)]]
( ([TIME[2011-12-13 21:57:27 +09:00]] 版))
<http://www.w3.org/TR/2011/REC-ws-eventing-20111213/#Dialect>

[27] [CITE@en[Web Services Enumeration (WS-Enumeration)]]
( ([TIME[2011-12-13 20:20:29 +09:00]] 版))
<http://www.w3.org/TR/2011/REC-ws-enumeration-20111213/#Dialect>

[28] [CITE@EN[W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes]]
( ([TIME[2012-04-05 06:34:51 +09:00]] 版))
<http://www.w3.org/TR/2012/REC-xmlschema11-2-20120405/#xr-assertions>

[29] [CITE@EN[W3C XML Schema Definition Language (XSD) 1.1 Part 1: Structures]]
( ([TIME[2012-04-05 06:34:07 +09:00]] 版))
<http://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/#Constraint_Summary>

[30] [CITE@EN[W3C XML Schema Definition Language (XSD) 1.1 Part 1: Structures]]
( ([TIME[2012-04-05 06:34:07 +09:00]] 版))
<http://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/#icd-selector>

[31] [CITE@EN[W3C XML Schema Definition Language (XSD) 1.1 Part 1: Structures]]
( ([TIME[2012-04-05 06:34:07 +09:00]] 版))
<http://www.w3.org/TR/2012/REC-xmlschema11-1-20120405/#sec-c-selector-xpath>

[32] [CITE[RIF Combination with XML data (Second Edition)]]
( ([TIME[2013-02-05 01:57:15 +09:00]] 版))
<http://www.w3.org/TR/2013/NOTE-rif-xml-data-20130205/>

[33] [CITE@en-us[The oxy_xpath() Function]]
( ([TIME[2013-08-04 01:30:45 +09:00]] 版))
<http://www.oxygenxml.com/doc/ug-editor/concepts/dg-xpath-function.html>

[34] [CITE@en[XML Signature Syntax and Processing Version 2.0]]
( ([TIME[2013-04-23 19:47:19 +09:00]] 版))
<http://www.w3.org/TR/xmldsig-core2/#sec-Type-xml>

[35] [CITE@en[396966 – Xpath 2.0]]
( ([TIME[2013-10-31 23:53:10 +09:00]] 版))
<https://bugzilla.mozilla.org/show_bug.cgi?id=396966>