HTTP Server in Prolog

Appeared in Volume 10/2, May 1997

gwait@bnr.co.uk
Graham Thwaites
28th January 1997

One of my colleagues is interested in developing an HTTP server in Prolog, and would be grateful for any references to existing public code or other information/suggestions.

Please reply to S.Gaito@bnr.co.uk

kxmorr4@uswest.com
Karen A. Morrissey
28th January 1997

I suggest you contact Peter Reintjes (reintjes@igc.net). Peter has been working on reversible parsers, and on HTML and SGML generation using Prolog.

lpa@cix.compulink.co.uk
Clive Spenser
29th January 1997

LPA are about to release its ProWeb Server which supports Prolog-based technology over the Web. It was presented recently at the LP/Internet workshop at Imperial College organized by Bob Kowalski, and will form the basis for Phil Vasey's tutorial at PAP'97.

For more information, check out:
http://www.demon.co.uk/ar/PAP97/tutorials.html

Full product information is at the LPA site:
http://www.lpa.co.uk

jonathan@pdc.dk
Jonathan Lerwill
31st January 1997

Writing a Web server in Prolog requires support for the HTTP protocol on a TCP/IP port (usually port 80). Visual Prolog 4.0 can be upgraded with a (free) TCP/IP module. The next version will probably include a HTTP parser so that Web pages can be read and written as Prolog structures.

We have chosen to use a Windows NT 4.0 server and the MS IIS server. This relieves us of having to write a HTTP server. We interface to the existing server software using the ISAPI interface (the DLL is written in Visual Prolog), which is more efficient than the "old" GCI interface.

ifprolog@pgtr0158.mch.sni.de
IFCO
31st January 1997

You may be interested in looking at some of IF Computers Logic Programming Web tools at http://www.ifcomputer.com

steph@context.mit.edu
Stephane Bressan
4th February 1997

ECLiPSe (the ECRC parallel constraint logic programming system) has an HTTP library (containing a client and server). You can find it at http://www.ecrc.de/eclipse/ under the "Tools, Libraries and Applications" section.

The library, which is described in some recent publications (http://context.mit.edu/Steph/home/Papers/inap96.ps.Z and http://context.mit.edu/Steph/Home/Papers/eclipse-agents.ps.Z) can be a starting point for your friend. Indeed, the version of the code you'll find is an early one and needs some revision. In particular, the HTTP grammar (for parsing and generating the MIME and HTTP headers) is out of date.

The server library allows you to define the implementation of the GET, POST, and PUT HTTP methods in Prolog, and other client-specific ones as required.

herme@fi.upm.es
Manuel Hermenegildo
6th February 1997

There is a Web page devoted to the topic of Internet and WWW programming using LP and CLP at:
http://www.clip.dia.fi.upm.es/lpnet/index.html

Any comments on this page would be very welcome.

You may want to check out the public domain PiLLoW library, which includes a comprehensive set of support predicates for Web programming from Prolog. It includes HTTP protocol support (i.e., pages can be retrieved from Prolog), an HTML parser, support for developing forms and parsing form output, etc.

The latest version of the PiLLow library is available via anonymous FTP from the CLIP ftp server:
ftp://clip.dia.fi.upm.es/pub/software/pillow.tar.gz

Please refer to the PiLLow Web site for more information:
http://www.clip.dia.fi.upm.es/miscdocs/pillow/pillow.html