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="documentation.xml"/>
<include file="examples.xml"/>
<include file="hacking.xml"/>
<include file="mailing.xml"/>
<include file="team.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="Latest News" link="news">

<section title="2003, September 23rd, Wednesday: Volunteers sought.">
<p>
We look for volunteers to prepare an emacs mode for CDuce and to implement  a native Win32 or MinGW port. If your are interested please contact 
us.
</p>
<br/>
</section>


<section title="2003, August 16th, Saturday: Version 0.1.1 released.">
<p>
This version has several bug-fixes and encodes reference types. You can now use
<code>:=</code> and <code>;</code>. It is available at the <a href="download">usual place</a>. Try this
<a href="http://www.cduce.org/cgi-bin/cduce?example=reference">code</a> on
the on-line demo for an example on how to use them, and refer to the
<a href="manual_expressions.html#ref">manual pages</a> for more
information.
</p>
<br/>
</section>
</box>


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

<p> <b>CDuce</b> is modern programming language, adapted to the
manipulation of XML documents.  It is developed 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">on-line 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 
  <footnote>

Valid with respect to validity constraints
that can be expressed by the type system (thus typically excluding 
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>).

  </footnote>);</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 features particular to CDuce:
</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>


</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 developed
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
developed 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	<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
2	<page name="index">
3
4	<title>Home page</title>
5	<banner>
6	<img title="CDuce" src="img/cduce_logo.jpg" width="400" height="206"
7	alt="CDuce"/>
8	</banner>
9
10	<left>
11	<p>On this page:</p>
12	<boxes-toc/>
13	<p>Under this page:</p>
14	<pages-toc/>
15	</left>
16
17	<external href="/cgi-bin/cduce" title="Online demo" name="proto"/>
18	<include file="download.xml"/>
19	<include file="bench.xml"/>
20	<include file="papers.xml"/>
21	<include file="documentation.xml"/>
22	<include file="examples.xml"/>
23	<include file="hacking.xml"/>
24	<include file="mailing.xml"/>
25	<include file="team.xml"/>
26	<include file="sitemap.xml"/>
27
28
29	<left>
30
31	<p> CDuce ("seduce") is a new typed functional language with
32	innovative features.</p>
33
34	<p> Although CDuce is a general programming language, it features
35	several characteristics that make it adapted to XML documents
36	manipulation (transformation, extraction of information, creation of
37	documents).
38	<a href="http://www.w3.org/XML/">XML</a> is a syntax to
39	describe tree-like documents (aka semi-structured data), and XML
40	documents often come with a description of their type. The type is
41	expressed in a system like DTD, or
42	<a href="http://www.w3.org/XML/Schema">XML Schema</a>.
43	XML types play a central role in CDuce.
44	</p>
45
46	</left>
47
48	<left>
49	<p> All pages of this site were automatically generated from an XML description of
50	the content by <a href="examples.html#site">the following CDuce program</a>.
51	</p><p>
52	<img src="img/cducepower2.jpg" alt="Powered by CDuce"/></p>
53	</left>
54
55	<box title="Latest News" link="news">
56
57	<section title="2003, September 23rd, Wednesday: Volunteers sought.">
58	<p>
59	We look for volunteers to prepare an emacs mode for CDuce and to implement a native Win32 or MinGW port. If your are interested please contact
60	us.
61	</p>
62	<br/>
63	</section>
64
65
66	<section title="2003, August 16th, Saturday: Version 0.1.1 released.">
67	<p>
68	This version has several bug-fixes and encodes reference types. You can now use
69	<code>:=</code> and <code>;</code>. It is available at the <a href="download">usual place</a>. Try this
70	<a href="http://www.cduce.org/cgi-bin/cduce?example=reference">code</a> on
71	the on-line demo for an example on how to use them, and refer to the
72	<a href="manual_expressions.html#ref">manual pages</a> for more
73	information.
74	</p>
75	<br/>
76	</section>
77	</box>
78
79
80	<box title="What is CDuce ?" link="whatis">
81
82	<p> <b>CDuce</b> is modern programming language, adapted to the
83	manipulation of XML documents. It is developed by the <a
84	href="http://www.di.ens.fr/~castagna/EQUIPE"><b>Languages</b></a>
85	group of ENS in Paris and the <a
86	href="http://www.lri.fr/bd"><b>Databases</b></a> group of LRI in
87	Orsay, two <a href="http://www.cnrs.fr">CNRS</a> labs.
88	See also the <local href="team">CDuce team</local> page,
89	our <local href="papers">technical papers</local>.
90	</p>
91
92	<section title="Getting more information">
93
94	<p>
95	If you want more information about CDuce you can send a mail to
96	<tt>info_at_cduce.org</tt> (replace <tt>_at_</tt> with <tt>@</tt>), or
97	to the most appropriate <a href="mailing.html">CDuce mailing list</a>.
98	</p>
99
100	</section>
101
102	<section title="Online running prototype">
103	<p> To get a feeling of CDuce,
104	you can play with the <local href="proto">on-line prototype</local>,
105	try the examples and modify them. We also have some
106	<local href="examples">larger examples</local>. </p>
107
108	<p>We are planning to distribute a stable release in the next
109	few weeks. To help us prepare this release, you can download a
110	<local href="download">beta version</local>, and send your comments.
111	</p>
112
113	</section>
114	</box>
115
116	<box title="Design and features" link="design">
117	<p> Our point of view and our guideline for the design of CDuce is
118	that a programming language for XML should take XML types (
119	DTD, XML Schema, Relax-NG, ...) seriously. The benefit are the following:</p>
120
121	<ul>
122	<li> <b>static verifications</b>
123	(e.g.: ensure that a transformation produces a valid document
124	<footnote>
125
126	Valid with respect to validity constraints
127	that can be expressed by the type system (thus typically excluding
128	constraints like <a
129	href="http://www.w3.org/TR/REC-xml#sec-attribute-types">ID</a> and
130	<a href="http://www.w3.org/TR/REC-xml#sec-attribute-types">IDREF</a>).
131
132	</footnote>);</li>
133	<li> in particular, we aim at <b>smooth and safe</b> compositions
134	of XML transformations, and incremental programming;</li>
135	<li> static <b>optimizations</b> and <b>efficient execution model</b>
136	(knowing the type of a document is crucial to extract information
137	efficiently).</li>
138	</ul>
139
140	<p>
141	Some features particular to CDuce:
142	</p>
143	<ul>
144	<li> XML objects can be manipulated as first-class citizen values:
145	elements, sequences, tags, characters and strings, attribute
146	sets; sequences of XML elements can be specified by
147	<b>regular expressions</b>, which also apply to
148	characters strings; </li>
149	<li> functions themselves are <b>first-class</b> values, they
150	can be manipulated, stored in data structure, returned by
151	a function,...</li>
152	<li> a powerful <b>pattern matching</b> operation can perform
153	complex extractions from sequences of XML elements; </li>
154	<li> a rich <b>type algebra</b>, with recursive types and arbitrary
155	boolean combinations (union, intersection, complement) allows
156	precise definitions of data structures and XML types;
157	<b>general purpose types</b> and types constructors are taken seriously
158	(products, extensible records, arbitrary precision integers with interval
159	constraints, Unicode characters);</li>
160	<li> <b>polymorphism</b> through a natural notion of <b>subtyping</b>,
161	and <b>overloaded functions</b> with dynamic dispatch; </li>
162	<li> an highly-effective <b>type-driven compilation schema</b>. </li>
163	</ul>
164
165	<p>CDuce is fast, functional,
166	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>,
167	<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
168	in alpha testing (and undocumented) while queries are being
169	implemented.
170	</p>
171
172	<p>
173	<local href="bench">Preliminary benchmarks</local> suggest that despite the
174	overhead for static type verification, a CDuce
175	program can run faster (30% to 60%) than an equivalent XSLT
176	style-sheet (we performed benchmarks with
177	the xsltproc tools from the Gnome libxslt library).
178	</p>
179
180
181	</box>
182
183	<box title="Research directions" link="research">
184
185	<p>Our plans concerning the design of the core language
186	include:</p>
187	<ul>
188	<li>a module system to support incremental programming;</li>
189	<li>parametric polymorphism;</li>
190	<li>XML-friendly primitives, to mimic XSLT transformations.</li>
191	</ul>
192
193	<p>
194	Apart from the core language design and implementation,
195	our research projects include:
196	</p>
197	<ul>
198	<li> integration of a <b>query sub-language</b> into CDuce, using
199	types as a primary optimization strategy for request evaluation;</li>
200	<li> study of <b>security</b> (confidentiality, ...) properties in the
201	setting of XML transformations.</li>
202	</ul>
203
204	<p>
205	We wrote several <local href="papers">technical papers</local> about
206	the language design and its theoretical foundations.
207	</p>
208	</box>
209
210	<box title="XDuce and CDuce" link="xduce">
211	<p>
212
213	The starting point of our work on CDuce was the
214	<a href="http://xduce.sourceforge.net/">XDuce</a> language developed
215	at the UPenn DB group. Many of CDuce features originate from XDuce.
216	Some of our achievements:
217
218	</p>
219	<ul>
220	<li>integration of first-class and overloaded functions, arbitrary boolean
221	connectives, and extensible (or not) records, to the semantic
222	definition of subtyping;</li>
223	<li>a subtyping algorithm without backtracking;</li>
224	<li>extending pattern matching to capture non consecutive
225	subsequences; removing tail condition for exact matching
226	(they arrived independently to another solution);</li>
227	<li>efficient evaluation model that takes profit of static type information;</li>
228	</ul>
229	<p>
230	Of course, the work on XDuce continued during our, and they
231	developed nice ideas: mixed attribute-element types (same
232	expressive power as our records, but they can sometimes avoid exponential
233	explosion where we cannot); powerful filter operation.
234	</p>
235
236	</box>
237
238	<box title="Related links" link="links">
239	<ul>
240	<li> <link url="http://www.w3.org/XML/"
241	title="Extensible Markup Language (XML)"> The W3C page on XML. </link>
242	</li>
243	<li> <link url="http://www.research.avayalabs.com/user/wadler/xml/"
244	title="XML: Some hyperlinks minus the hype"> By Philip Wadler. </link>
245	</li>
246	<li> <link url="http://xduce.sourceforge.net/"
247	title="XDuce"> XDuce home page. </link> </li>
248	</ul> </box>
249
250
251	<meta>
252	<p>
253	<a href="comeon.htm">
254	<img style="border:0;width:88px;height:31px"
255	src="img/cducepower3.png"
256	alt="Powered by CDuce"/>
257	</a>
258
259	<a href="http://validator.w3.org/check?uri=http%3A%2F%2Fwww.cduce.org">
260	<img style="border:0;width:88px;height:31px"
261	src="http://www.w3.org/Icons/valid-xhtml10"
262	alt="Valid XHTML 1.0!"/>
263	</a>
264
265	<a href="http://jigsaw.w3.org/css-validator/">
266	<img style="border:0;width:88px;height:31px"
267	src="http://jigsaw.w3.org/css-validator/images/vcss"
268	alt="Valid CSS!"/>
269	</a>
270
271	<a href="http://www.ens.fr">
272	<img style="border:0"
273	src="img//symbENSmio.gif"
274	alt="ENS" title="ENS"/>
275	</a>
276
277	<a href="http://www.u-psud.fr">
278	<img style="border:0"
279	src="img//symbP11mio.gif"
280	alt="Paris 11" title="Paris 11"/>
281	</a>
282
283	<a href="http://www.cnrs.fr">
284	<img style="border:0"
285	src="img//symbCNRSmio.gif"
286	alt="CNRS" title="CNRS"/>
287	</a>
288	</p>
289	<p>
290	<a href="mailto:Alain.Frisch@ens.fr">Webmaster</a> -
291	<local href="sitemap">Site map</local>
292	</p>
293	</meta>
294
295	</page>