viewcvs.cgi/web/index.xml

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

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

<!-- ********* Left panel ********* -->
<navig>

<toc/>

<box>
<ul>
<li><a href="/cgi-bin/cduce">Online demo</a></li>
<li><a href="papers.html">Technical papers and talks</a></li>
<li><a href="team.html">CDuce team</a></li>
<li><a href="plan.html">Site map</a></li>
<li><a href="bench.html">Site map</a></li>
</ul>
</box>

<box>

<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>

</box>

<box>
<p> This site was automatically generated from an XML description of
the content by a CDuce program. 
<img src="img/cducepower2.jpg" alt="Powered by CDuce"/></p>
</box>

<toc/>


</navig>

<!-- ********* Main panel ********* -->

<main>

<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 <a href="team.html">CDuce team</a> page,
and our <a href="papers.html">technical papers</a>.
</p>

<section title="Online running prototype">
<p> The only available implementation of CDuce is an <a
href="cgi-bin/cduce">online prototype</a>. To get a feeling of CDuce,
you can try the examples and play with them, or have a look at this <a
href="memento.html">memento</a> which briefly explains the syntax of
the language.  </p>

<p>We are planning to distribute a first public release in the next
few weeks.</p> 
</section>
</box>

<box title="Design and features" link="whatis">
<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. We expect the following
benefits:</p>

<ul>
<li> <b>static verifications</b>
(e.g.: ensure that a transformation produces a valid document);</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>
<a href="bench.html">Preliminary benchmarks</a> suggest that 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>
</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 <a href="papers.html">technical papers</a> 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.research.avayalabs.com/user/wadler/xml/"
title="XML: Some hyperlinks minus the hype"> By Philip Wadler. </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/validator?uri=http://www.cduce.org">
<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> -
<a href="plan.html">Site map</a>
</p>
</meta>

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