viewcvs.cgi/web/index.xml

<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
<page name="index">

<title>Home page</title>
<banner>
  <img title="CDuce" src="img/cduce_logo.jpg" width="400" height="206"
       alt="CDuce"/>
</banner>

<left>
<p>On this page:</p>
<boxes-toc/>
<p>Under this page:</p>
<pages-toc/>
</left>

<external href="/cgi-bin/cduce" title="Online demo" name="proto"/>
<include file="download.xml"/>
<include file="bench.xml"/>
<include file="papers.xml"/>
<include file="examples.xml"/>
<include file="team.xml"/>
<include file="manual.xml"/>
<include file="mailing.xml"/>
<include file="sitemap.xml"/>


<left>

<p> CDuce ("seduce") is a new typed functional language with
innovative features.</p>

<p> Although CDuce is a general programming language, it features
several characteristics that make it adapted to XML documents
manipulation (transformation, extraction of information, creation of
documents).  
<a href="http://www.w3.org/XML/">XML</a> is a syntax to
describe tree-like documents (aka semi-structured data), and XML
documents often come with a description of their type. The type is
expressed in a system like DTD, or 
<a href="http://www.w3.org/XML/Schema">XML Schema</a>.
XML types play a central role in CDuce.
  </p>

</left>

<left>
<p> All pages of this site were automatically generated from an XML description of
the content by <a href="examples.html#site">the following CDuce program</a>.
</p><p> 
<img src="img/cducepower2.jpg" alt="Powered by CDuce"/></p>
</left>


<box title="What is CDuce ?" link="whatis">

<p> <b>CDuce</b> is modern programming language, adapted to the
manipulation of XML documents.  It is developped by the <a
href="http://www.di.ens.fr/~castagna/EQUIPE"><b>Languages</b></a>
group of ENS in Paris and the <a
href="http://www.lri.fr/bd"><b>Databases</b></a> group of LRI in
Orsay, two <a href="http://www.cnrs.fr">CNRS</a> labs.
See also the <local href="team">CDuce team</local> page,
our <local href="papers">technical papers</local>.
</p>

<section title="Getting more information">

<p>
If you want more information about CDuce you can send a mail to 
<tt>info_at_cduce.org</tt> (replace <tt>_at_</tt> with <tt>@</tt>), or
to the most appropriate <a href="mailing.html">CDuce mailing list</a>.
</p>

</section>

<section title="Online running prototype">
<p> To get a feeling of CDuce,
you can play with the <local href="proto">online prototype</local>,
try the examples and modify them. We also have some 
<local href="examples">larger examples</local>. </p>

<p>We are planning to distribute a stable release in the next
few weeks. To help us prepare this release, you can download a
<local href="download">beta version</local>, and send your comments.
</p>

</section>
</box>

<box title="Design and features" link="design">
<p> Our point of view and our guideline for the design of CDuce is
that a programming language for XML should take XML types (
DTD, XML Schema, Relax-NG, ...) seriously. The benefit are the following:</p>

<ul>
<li> <b>static verifications</b>
(e.g.: ensure that a transformation produces a valid document<a href="#ftn1"><sup>1</sup></a>);</li>
<li> in particular, we aim at <b>smooth and safe</b> compositions
of XML transformations, and incremental programming;</li>
<li> static <b>optimizations</b> and <b>efficient execution model</b>
(knowing the type of a document is crucial to extract information 
efficiently).</li> 
</ul>

<p>
Some of CDuce peculiar features:
</p>
<ul>
<li> XML objects can be manipulated as first-class citizen values:
     elements, sequences, tags, characters and strings, attribute
     sets; sequences of XML elements can be specified by 
     <b>regular expressions</b>, which also apply to
     characters strings; </li>
<li> functions themselves are <b>first-class</b> values, they
     can be manipulated, stored in data structure, returned by
     a function,...</li>
<li> a powerful <b>pattern matching</b> operation can perform
     complex extractions from sequences of XML elements; </li>
<li> a rich <b>type algebra</b>, with recursive types and arbitrary
     boolean combinations (union, intersection, complement) allows
     precise definitions of data structures and XML types;
     <b>general purpose types</b> and types constructors are taken seriously
     (products, extensible records, arbitrary precision integers with interval
     constraints,  Unicode characters);</li>
<li> <b>polymorphism</b> through a natural notion of <b>subtyping</b>,
     and <b>overloaded functions</b> with dynamic dispatch; </li>
<li> an highly-effective <b>type-driven compilation schema</b>. </li>
</ul>

<p>CDuce is fast, functional,
type-safe, and <b>conforms to basic standards</b>: <a href="http://www.unicode.org">Unicode</a>, <a href="http://www.w3.org/XML/">XML</a>, <a href="http://www.w3.org/TR/REC-xml#dt-doctype">DTD</a>,
<a href="http://www.w3.org/TR/REC-xml-names/">Namespaces</a> are fully supported, partial support of <a href="http://www.w3.org/TR/xmlschema-1/">XML Schema</a> validation is
in alpha testing (and undocumented) while queries are being
implemented.
</p>

<p>
<local href="bench">Preliminary benchmarks</local> suggest that despite the
overhead for static type verification, a CDuce
program can run faster (30% to 60%) than an equivalent XSLT
style-sheet (we performed benchmarks with
the xsltproc tools from the Gnome libxslt library).
</p>
<p style="font-size:8px"><a name="ftn1"><sup>1</sup></a>Valid with respect to validity constraints
that can be expressed by the type system (thus typically excluding the
constraints like <a href="http://www.w3.org/TR/REC-xml#sec-attribute-types">ID</a> and
<a href="http://www.w3.org/TR/REC-xml#sec-attribute-types">IDREF</a>).
</p>
</box>

<box title="Research directions" link="research">

<p>Our plans concerning the design of the core language
include:</p>
<ul>
 <li>a module system to support incremental programming;</li>
 <li>parametric polymorphism;</li>
 <li>XML-friendly primitives, to mimic XSLT transformations.</li>
</ul>

<p>
Apart from the core language design and implementation, 
our research projects include:
</p>
<ul>
<li> integration of a <b>query sub-language</b> into CDuce, using
     types as a primary optimization strategy for request evaluation;</li>
<li> study of <b>security</b> (confidentiality, ...) properties in the
     setting of XML transformations.</li>
</ul>

<p>
We wrote several <local href="papers">technical papers</local> about
the language design and its theoretical foundations.
</p>
</box>

<box title="XDuce and CDuce" link="xduce">
<p>

The starting point of our work on CDuce was the
<a href="http://xduce.sourceforge.net/">XDuce</a> language developped
at the UPenn DB group. Many of CDuce features originate from XDuce.
Some of our achievements:

</p>
<ul>
<li>integration of first-class and overloaded functions, arbitrary boolean
    connectives, and extensible (or not) records, to the semantic
    definition of subtyping;</li>
<li>a subtyping algorithm without backtracking;</li>
<li>extending pattern matching to capture non consecutive
    subsequences; removing tail condition for exact matching
    (they arrived independently to another solution);</li>
<li>efficient evaluation model that takes profit of static type information;</li>
</ul>
<p>
Of course, the work on XDuce continued during our, and they
developped nice ideas: mixed attribute-element types (same
expressive power as our records, but they can sometimes avoid exponential
explosion where we cannot); powerful filter operation.
</p>

</box>

<box title="Related links" link="links">
<ul>
<li> <link url="http://www.w3.org/XML/"
title="Extensible Markup Language (XML)"> The W3C page on XML. </link>
</li>
<li> <link url="http://www.research.avayalabs.com/user/wadler/xml/"
title="XML: Some hyperlinks minus the hype"> By Philip Wadler. </link>
</li>
<li> <link url="http://xduce.sourceforge.net/"
title="XDuce"> XDuce home page. </link> </li>
</ul> </box>


<meta>
<p>
<a href="comeon.htm">
<img style="border:0;width:88px;height:31px"
     src="img/cducepower3.png" 
     alt="Powered by CDuce"/>
</a>

<a href="http://validator.w3.org/check?uri=http%3A%2F%2Fwww.cduce.org">
<img style="border:0;width:88px;height:31px"
     src="http://www.w3.org/Icons/valid-xhtml10"
     alt="Valid XHTML 1.0!"/>
</a>

<a href="http://jigsaw.w3.org/css-validator/">
<img style="border:0;width:88px;height:31px"
     src="http://jigsaw.w3.org/css-validator/images/vcss" 
     alt="Valid CSS!"/>
</a>

<a href="http://www.ens.fr">
<img style="border:0"
     src="img//symbENSmio.gif"
     alt="ENS" title="ENS"/>
</a>

<a href="http://www.u-psud.fr">
<img style="border:0" 
     src="img//symbP11mio.gif" 
     alt="Paris 11" title="Paris 11"/>
</a>

<a href="http://www.cnrs.fr">
<img style="border:0" 
     src="img//symbCNRSmio.gif" 
     alt="CNRS" title="CNRS"/>
</a>
</p>
<p>
<a href="mailto:Alain.Frisch@ens.fr">Webmaster</a> -
<local href="sitemap">Site map</local>
</p>
</meta>

</page>
1	abate	253	<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
2	abate	341	<page name="index">
3	abate	253
4	abate	350	<title>Home page</title>
5	abate	253	<banner>
6			<img title="CDuce" src="img/cduce_logo.jpg" width="400" height="206"
7			alt="CDuce"/>
8			</banner>
9
10	abate	341	<left>
11			<p>On this page:</p>
12			<boxes-toc/>
13			<p>Under this page:</p>
14			<pages-toc/>
15			</left>
16	abate	253
17	abate	341	<external href="/cgi-bin/cduce" title="Online demo" name="proto"/>
18	abate	437	<include file="download.xml"/>
19	abate	341	<include file="bench.xml"/>
20			<include file="papers.xml"/>
21			<include file="examples.xml"/>
22			<include file="team.xml"/>
23	abate	381	<include file="manual.xml"/>
24	abate	598	<include file="mailing.xml"/>
25	abate	341	<include file="sitemap.xml"/>
26	abate	253
27	abate	576
28	abate	341	<left>
29	abate	255
30	abate	253	<p> CDuce ("seduce") is a new typed functional language with
31	abate	258	innovative features.</p>
32	abate	253
33			<p> Although CDuce is a general programming language, it features
34			several characteristics that make it adapted to XML documents
35			manipulation (transformation, extraction of information, creation of
36			documents).
37			<a href="http://www.w3.org/XML/">XML</a> is a syntax to
38			describe tree-like documents (aka semi-structured data), and XML
39			documents often come with a description of their type. The type is
40			expressed in a system like DTD, or
41	abate	258	<a href="http://www.w3.org/XML/Schema">XML Schema</a>.
42			XML types play a central role in CDuce.
43			</p>
44	abate	253
45	abate	341	</left>
46	abate	253
47	abate	341	<left>
48	abate	305	<p> All pages of this site were automatically generated from an XML description of
49	abate	347	the content by <a href="examples.html#site">the following CDuce program</a>.
50	abate	267	</p><p>
51	abate	253	<img src="img/cducepower2.jpg" alt="Powered by CDuce"/></p>
52	abate	341	</left>
53	abate	253
54
55	abate	258	<box title="What is CDuce ?" link="whatis">
56	abate	253
57	abate	258	<p> <b>CDuce</b> is modern programming language, adapted to the
58			manipulation of XML documents. It is developped by the <a
59			href="http://www.di.ens.fr/~castagna/EQUIPE"><b>Languages</b></a>
60			group of ENS in Paris and the <a
61			href="http://www.lri.fr/bd"><b>Databases</b></a> group of LRI in
62			Orsay, two <a href="http://www.cnrs.fr">CNRS</a> labs.
63	abate	347	See also the <local href="team">CDuce team</local> page,
64			our <local href="papers">technical papers</local>.
65	abate	258	</p>
66
67	abate	591	<section title="Getting more information">
68
69			<p>
70	abate	598	If you want more information about CDuce you can send a mail to
71			<tt>info_at_cduce.org</tt> (replace <tt>_at_</tt> with <tt>@</tt>), or
72			to the most appropriate <a href="mailing.html">CDuce mailing list</a>.
73	abate	591	</p>
74
75			</section>
76
77	abate	253	<section title="Online running prototype">
78	abate	437	<p> To get a feeling of CDuce,
79			you can play with the <local href="proto">online prototype</local>,
80			try the examples and modify them. We also have some
81			<local href="examples">larger examples</local>. </p>
82	abate	253
83	abate	562	<p>We are planning to distribute a stable release in the next
84			few weeks. To help us prepare this release, you can download a
85			<local href="download">beta version</local>, and send your comments.
86	abate	437	</p>
87
88	abate	258	</section>
89	abate	253	</box>
90
91	abate	341	<box title="Design and features" link="design">
92	abate	258	<p> Our point of view and our guideline for the design of CDuce is
93			that a programming language for XML should take XML types (
94	abate	545	DTD, XML Schema, Relax-NG, ...) seriously. The benefit are the following:</p>
95	abate	253
96	abate	258	<ul>
97			<li> <b>static verifications</b>
98	abate	614	(e.g.: ensure that a transformation produces a valid document<a href="#ftn1"><sup>1</sup></a>);</li>
99	abate	258	<li> in particular, we aim at <b>smooth and safe</b> compositions
100			of XML transformations, and incremental programming;</li>
101			<li> static <b>optimizations</b> and <b>efficient execution model</b>
102			(knowing the type of a document is crucial to extract information
103			efficiently).</li>
104	abate	253	</ul>
105
106	abate	258	<p>
107			Some of CDuce peculiar features:
108			</p>
109	abate	253	<ul>
110	abate	258	<li> XML objects can be manipulated as first-class citizen values:
111			elements, sequences, tags, characters and strings, attribute
112			sets; sequences of XML elements can be specified by
113			<b>regular expressions</b>, which also apply to
114			characters strings; </li>
115			<li> functions themselves are <b>first-class</b> values, they
116			can be manipulated, stored in data structure, returned by
117			a function,...</li>
118			<li> a powerful <b>pattern matching</b> operation can perform
119			complex extractions from sequences of XML elements; </li>
120			<li> a rich <b>type algebra</b>, with recursive types and arbitrary
121			boolean combinations (union, intersection, complement) allows
122			precise definitions of data structures and XML types;
123			<b>general purpose types</b> and types constructors are taken seriously
124			(products, extensible records, arbitrary precision integers with interval
125			constraints, Unicode characters);</li>
126			<li> <b>polymorphism</b> through a natural notion of <b>subtyping</b>,
127			and <b>overloaded functions</b> with dynamic dispatch; </li>
128			<li> an highly-effective <b>type-driven compilation schema</b>. </li>
129			</ul>
130	abate	253
131	abate	565	<p>CDuce is fast, functional,
132			type-safe, and <b>conforms to basic standards</b>: <a href="http://www.unicode.org">Unicode</a>, <a href="http://www.w3.org/XML/">XML</a>, <a href="http://www.w3.org/TR/REC-xml#dt-doctype">DTD</a>,
133			<a href="http://www.w3.org/TR/REC-xml-names/">Namespaces</a> are fully supported, partial support of <a href="http://www.w3.org/TR/xmlschema-1/">XML Schema</a> validation is
134			in alpha testing (and undocumented) while queries are being
135			implemented.
136			</p>
137
138	abate	258	<p>
139	abate	347	<local href="bench">Preliminary benchmarks</local> suggest that despite the
140	abate	300	overhead for static type verification, a CDuce
141	abate	258	program can run faster (30% to 60%) than an equivalent XSLT
142			style-sheet (we performed benchmarks with
143			the xsltproc tools from the Gnome libxslt library).
144			</p>
145	abate	614	<p style="font-size:8px"><a name="ftn1"><sup>1</sup></a>Valid with respect to validity constraints
146			that can be expressed by the type system (thus typically excluding the
147			constraints like <a href="http://www.w3.org/TR/REC-xml#sec-attribute-types">ID</a> and
148			<a href="http://www.w3.org/TR/REC-xml#sec-attribute-types">IDREF</a>).
149			</p>
150	abate	258	</box>
151	abate	253
152	abate	258	<box title="Research directions" link="research">
153	abate	253
154	abate	258	<p>Our plans concerning the design of the core language
155			include:</p>
156			<ul>
157			<li>a module system to support incremental programming;</li>
158			<li>parametric polymorphism;</li>
159			<li>XML-friendly primitives, to mimic XSLT transformations.</li>
160	abate	253	</ul>
161
162	abate	258	<p>
163			Apart from the core language design and implementation,
164			our research projects include:
165			</p>
166	abate	253	<ul>
167	abate	258	<li> integration of a <b>query sub-language</b> into CDuce, using
168			types as a primary optimization strategy for request evaluation;</li>
169			<li> study of <b>security</b> (confidentiality, ...) properties in the
170			setting of XML transformations.</li>
171	abate	253	</ul>
172
173	abate	258	<p>
174	abate	347	We wrote several <local href="papers">technical papers</local> about
175	abate	258	the language design and its theoretical foundations.
176			</p>
177	abate	253	</box>
178
179	abate	258	<box title="XDuce and CDuce" link="xduce">
180			<p>
181	abate	253
182	abate	258	The starting point of our work on CDuce was the
183			<a href="http://xduce.sourceforge.net/">XDuce</a> language developped
184			at the UPenn DB group. Many of CDuce features originate from XDuce.
185			Some of our achievements:
186	abate	253
187	abate	258	</p>
188			<ul>
189			<li>integration of first-class and overloaded functions, arbitrary boolean
190			connectives, and extensible (or not) records, to the semantic
191			definition of subtyping;</li>
192			<li>a subtyping algorithm without backtracking;</li>
193			<li>extending pattern matching to capture non consecutive
194			subsequences; removing tail condition for exact matching
195			(they arrived independently to another solution);</li>
196			<li>efficient evaluation model that takes profit of static type information;</li>
197	abate	253	</ul>
198	abate	258	<p>
199			Of course, the work on XDuce continued during our, and they
200			developped nice ideas: mixed attribute-element types (same
201			expressive power as our records, but they can sometimes avoid exponential
202			explosion where we cannot); powerful filter operation.
203			</p>
204	abate	614
205	abate	253	</box>
206
207			<box title="Related links" link="links">
208			<ul>
209	abate	352	<li> <link url="http://www.w3.org/XML/"
210			title="Extensible Markup Language (XML)"> The W3C page on XML. </link>
211			</li>
212	abate	253	<li> <link url="http://www.research.avayalabs.com/user/wadler/xml/"
213			title="XML: Some hyperlinks minus the hype"> By Philip Wadler. </link>
214	abate	352	</li>
215			<li> <link url="http://xduce.sourceforge.net/"
216			title="XDuce"> XDuce home page. </link> </li>
217			</ul> </box>
218	abate	253
219
220			<meta>
221			<p>
222			<a href="comeon.htm">
223			<img style="border:0;width:88px;height:31px"
224			src="img/cducepower3.png"
225			alt="Powered by CDuce"/>
226			</a>
227
228	abate	257	<a href="http://validator.w3.org/check?uri=http%3A%2F%2Fwww.cduce.org">
229	abate	253	<img style="border:0;width:88px;height:31px"
230			src="http://www.w3.org/Icons/valid-xhtml10"
231			alt="Valid XHTML 1.0!"/>
232			</a>
233
234	abate	401	<a href="http://jigsaw.w3.org/css-validator/">
235	abate	253	<img style="border:0;width:88px;height:31px"
236			src="http://jigsaw.w3.org/css-validator/images/vcss"
237			alt="Valid CSS!"/>
238			</a>
239
240			<a href="http://www.ens.fr">
241			<img style="border:0"
242			src="img//symbENSmio.gif"
243			alt="ENS" title="ENS"/>
244			</a>
245
246			<a href="http://www.u-psud.fr">
247			<img style="border:0"
248			src="img//symbP11mio.gif"
249			alt="Paris 11" title="Paris 11"/>
250			</a>
251
252			<a href="http://www.cnrs.fr">
253			<img style="border:0"
254			src="img//symbCNRSmio.gif"
255			alt="CNRS" title="CNRS"/>
256			</a>
257			</p>
258			<p>
259	abate	255	<a href="mailto:Alain.Frisch@ens.fr">Webmaster</a> -
260	abate	347	<local href="sitemap">Site map</local>
261	abate	253	</p>
262			</meta>
263
264			</page>