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="bench.xml"/>
<include file="memento.xml"/>
<include file="papers.xml"/>
<include file="examples.xml"/>
<include file="team.xml"/>
<include file="tutorial.xml"/>
<include file="manual.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="Online running prototype">
<p> The only available implementation of CDuce is an <local
href="proto">online prototype</local>. To get a feeling of CDuce,
you can try the examples and play with them, or have a look at this <local
href="memento">memento</local> which briefly explains the syntax of
the language. We also have some <local href="examples">larger
examples</local>. </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="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. 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>
<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>
</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/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> -
<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			<include file="bench.xml"/>
19			<include file="memento.xml"/>
20			<include file="papers.xml"/>
21			<include file="examples.xml"/>
22			<include file="team.xml"/>
23			<include file="tutorial.xml"/>
24	abate	381	<include file="manual.xml"/>
25	abate	341	<include file="sitemap.xml"/>
26	abate	253
27	abate	341	<left>
28	abate	255
29	abate	253	<p> CDuce ("seduce") is a new typed functional language with
30	abate	258	innovative features.</p>
31	abate	253
32			<p> Although CDuce is a general programming language, it features
33			several characteristics that make it adapted to XML documents
34			manipulation (transformation, extraction of information, creation of
35			documents).
36			<a href="http://www.w3.org/XML/">XML</a> is a syntax to
37			describe tree-like documents (aka semi-structured data), and XML
38			documents often come with a description of their type. The type is
39			expressed in a system like DTD, or
40	abate	258	<a href="http://www.w3.org/XML/Schema">XML Schema</a>.
41			XML types play a central role in CDuce.
42			</p>
43	abate	253
44	abate	341	</left>
45	abate	253
46	abate	341	<left>
47	abate	305	<p> All pages of this site were automatically generated from an XML description of
48	abate	347	the content by <a href="examples.html#site">the following CDuce program</a>.
49	abate	267	</p><p>
50	abate	253	<img src="img/cducepower2.jpg" alt="Powered by CDuce"/></p>
51	abate	341	</left>
52	abate	253
53
54	abate	258	<box title="What is CDuce ?" link="whatis">
55	abate	253
56	abate	258	<p> <b>CDuce</b> is modern programming language, adapted to the
57			manipulation of XML documents. It is developped by the <a
58			href="http://www.di.ens.fr/~castagna/EQUIPE"><b>Languages</b></a>
59			group of ENS in Paris and the <a
60			href="http://www.lri.fr/bd"><b>Databases</b></a> group of LRI in
61			Orsay, two <a href="http://www.cnrs.fr">CNRS</a> labs.
62	abate	347	See also the <local href="team">CDuce team</local> page,
63			our <local href="papers">technical papers</local>.
64	abate	258	</p>
65
66	abate	253	<section title="Online running prototype">
67	abate	348	<p> The only available implementation of CDuce is an <local
68			href="proto">online prototype</local>. To get a feeling of CDuce,
69	abate	347	you can try the examples and play with them, or have a look at this <local
70			href="memento">memento</local> which briefly explains the syntax of
71			the language. We also have some <local href="examples">larger
72			examples</local>. </p>
73	abate	253
74	abate	258	<p>We are planning to distribute a first public release in the next
75			few weeks.</p>
76			</section>
77	abate	253	</box>
78
79	abate	341	<box title="Design and features" link="design">
80	abate	258	<p> Our point of view and our guideline for the design of CDuce is
81			that a programming language for XML should take XML types (
82			DTD, XML Schema, Relax-NG, ...) seriously. We expect the following
83			benefits:</p>
84	abate	253
85	abate	258	<ul>
86			<li> <b>static verifications</b>
87			(e.g.: ensure that a transformation produces a valid document);</li>
88			<li> in particular, we aim at <b>smooth and safe</b> compositions
89			of XML transformations, and incremental programming;</li>
90			<li> static <b>optimizations</b> and <b>efficient execution model</b>
91			(knowing the type of a document is crucial to extract information
92			efficiently).</li>
93	abate	253	</ul>
94
95	abate	258	<p>
96			Some of CDuce peculiar features:
97			</p>
98	abate	253	<ul>
99	abate	258	<li> XML objects can be manipulated as first-class citizen values:
100			elements, sequences, tags, characters and strings, attribute
101			sets; sequences of XML elements can be specified by
102			<b>regular expressions</b>, which also apply to
103			characters strings; </li>
104			<li> functions themselves are <b>first-class</b> values, they
105			can be manipulated, stored in data structure, returned by
106			a function,...</li>
107			<li> a powerful <b>pattern matching</b> operation can perform
108			complex extractions from sequences of XML elements; </li>
109			<li> a rich <b>type algebra</b>, with recursive types and arbitrary
110			boolean combinations (union, intersection, complement) allows
111			precise definitions of data structures and XML types;
112			<b>general purpose types</b> and types constructors are taken seriously
113			(products, extensible records, arbitrary precision integers with interval
114			constraints, Unicode characters);</li>
115			<li> <b>polymorphism</b> through a natural notion of <b>subtyping</b>,
116			and <b>overloaded functions</b> with dynamic dispatch; </li>
117			<li> an highly-effective <b>type-driven compilation schema</b>. </li>
118			</ul>
119	abate	253
120	abate	258	<p>
121	abate	347	<local href="bench">Preliminary benchmarks</local> suggest that despite the
122	abate	300	overhead for static type verification, a CDuce
123	abate	258	program can run faster (30% to 60%) than an equivalent XSLT
124			style-sheet (we performed benchmarks with
125			the xsltproc tools from the Gnome libxslt library).
126			</p>
127			</box>
128	abate	253
129	abate	258	<box title="Research directions" link="research">
130	abate	253
131	abate	258	<p>Our plans concerning the design of the core language
132			include:</p>
133			<ul>
134			<li>a module system to support incremental programming;</li>
135			<li>parametric polymorphism;</li>
136			<li>XML-friendly primitives, to mimic XSLT transformations.</li>
137	abate	253	</ul>
138
139	abate	258	<p>
140			Apart from the core language design and implementation,
141			our research projects include:
142			</p>
143	abate	253	<ul>
144	abate	258	<li> integration of a <b>query sub-language</b> into CDuce, using
145			types as a primary optimization strategy for request evaluation;</li>
146			<li> study of <b>security</b> (confidentiality, ...) properties in the
147			setting of XML transformations.</li>
148	abate	253	</ul>
149
150	abate	258	<p>
151	abate	347	We wrote several <local href="papers">technical papers</local> about
152	abate	258	the language design and its theoretical foundations.
153			</p>
154	abate	253	</box>
155
156	abate	258	<box title="XDuce and CDuce" link="xduce">
157			<p>
158	abate	253
159	abate	258	The starting point of our work on CDuce was the
160			<a href="http://xduce.sourceforge.net/">XDuce</a> language developped
161			at the UPenn DB group. Many of CDuce features originate from XDuce.
162			Some of our achievements:
163	abate	253
164	abate	258	</p>
165			<ul>
166			<li>integration of first-class and overloaded functions, arbitrary boolean
167			connectives, and extensible (or not) records, to the semantic
168			definition of subtyping;</li>
169			<li>a subtyping algorithm without backtracking;</li>
170			<li>extending pattern matching to capture non consecutive
171			subsequences; removing tail condition for exact matching
172			(they arrived independently to another solution);</li>
173			<li>efficient evaluation model that takes profit of static type information;</li>
174	abate	253	</ul>
175	abate	258	<p>
176			Of course, the work on XDuce continued during our, and they
177			developped nice ideas: mixed attribute-element types (same
178			expressive power as our records, but they can sometimes avoid exponential
179			explosion where we cannot); powerful filter operation.
180			</p>
181	abate	253	</box>
182
183			<box title="Related links" link="links">
184			<ul>
185	abate	352	<li> <link url="http://www.w3.org/XML/"
186			title="Extensible Markup Language (XML)"> The W3C page on XML. </link>
187			</li>
188	abate	253	<li> <link url="http://www.research.avayalabs.com/user/wadler/xml/"
189			title="XML: Some hyperlinks minus the hype"> By Philip Wadler. </link>
190	abate	352	</li>
191			<li> <link url="http://xduce.sourceforge.net/"
192			title="XDuce"> XDuce home page. </link> </li>
193			</ul> </box>
194	abate	253
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	abate	257	<a href="http://validator.w3.org/check?uri=http%3A%2F%2Fwww.cduce.org">
205	abate	253	<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	abate	257	<a href="http://jigsaw.w3.org/css-validator/validator?uri=http://www.cduce.org">
211	abate	253	<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	abate	255	<a href="mailto:Alain.Frisch@ens.fr">Webmaster</a> -
236	abate	347	<local href="sitemap">Site map</local>
237	abate	253	</p>
238			</meta>
239
240			</page>