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.php">Papers and talks</a></li>
<li><a href="team.php">CDuce team</a></li>
<li><a href="plan.php">Site map</a></li>
<li><a href="bench.php">Benchmarks</a></li>
<li><a href="examples.php">Examples</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.php">CDuce team</a> page,
our <a href="papers.php">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.php">memento</a> which briefly explains the syntax of
the language. We also have some <a href="examples.php">larger
examples</a>. </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.php">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.php">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.php">Site map</a>
</p>
</meta>

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