SWI-Prolog and the Web

TL;DR

This paper introduces a Prolog-based architecture for Web applications that communicates via standard HTTP, simplifying development and deployment while supporting Web document formats like HTML, XML, and RDF.

Contribution

It presents new Prolog libraries and extensions for handling Web protocols and documents, enabling efficient processing of large Web data types.

Findings

Supports a wide range of Web applications including HTML, XML, and RDF.

Enables Prolog to communicate over HTTP without embedding in external Web servers.

Designed for efficient handling of large Web documents.

Abstract

Where Prolog is commonly seen as a component in a Web application that is either embedded or communicates using a proprietary protocol, we propose an architecture where Prolog communicates to other components in a Web application using the standard HTTP protocol. By avoiding embedding in external Web servers development and deployment become much easier. To support this architecture, in addition to the transfer protocol, we must also support parsing, representing and generating the key Web document types such as HTML, XML and RDF. This paper motivates the design decisions in the libraries and extensions to Prolog for handling Web documents and protocols. The design has been guided by the requirement to handle large documents efficiently. The described libraries support a wide range of Web applications ranging from HTML and XML documents to Semantic Web RDF processing. To appear in Theory and Practice of Logic Programming (TPLP)