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