A generic program is written once and works on values of many data types. Generic Haskell is a recent extension of the functional programming language Haskell that supports generic programming. This paper discusses how Generic Haskell can be used to implement XML tools whose behaviour depends on the DTD or Schema of the input XML document. Example tools include XML editors, databases, and compressors. Generic Haskell is ideally suited for implementing XML tools: .

A generic program is written once, and works on values of a large class of data types (or DTD's, schemas, structures, class hierarchies). This paper shows how generic programming can be used to implement XML tools such as XML editors, databases, and compressors, that depend on the DTD of an input XML document. The resulting tools usually perform better because knowledge of the DTD can be used to optimise the tools, and are smaller, because all DTD handling is dealt with in the generic programming compiler. The paper shows how an XML compressor is implemented as a generic program, and it discusses which other classes of XML tools would profit from an implementation as a generic program.