Implementation of the XML linking language XLink by functional methods

This paper is devoted to the construction of processors of a language for describing links between resources in XML documents, which is based on the application of functional programming methods and representation of XML data as S-expressions. An implementation in the high-level functional programming language Scheme, the system SXLink compatible with the XLink specification of the W3 consortium, is considered. A survey and comparative analysis of the existing implementations of the XLink language are given. Typical difficulties associated with the implementation and use of the language are identified, and methods to overcome them are discussed. Examples of the application of the SXLink system to solving problems of processing links between resources in XML documents are considered. An SXLink application program interface based on the use of functions of the Scheme language as first-class objects is suggested. The application of this approach to constructing simple and powerful XLink processors is discussed.