This version of the algebra has been superseded by the July 2000 version.
Also see XML: Some hyperlinks minus the hype.
This note presents a possible data model and algebra for an XML query language.
The data model and algebra have been implemented in the functional programming language Haskell. We use a variant of Haskell that supports regular expression comprehensions. Mark Jones of OGI has been kind enough to prepare a version of his Hugs interpreter that supports the variant. You can download Hugs from the usual location, listed below. Then either download the hugs.exe file for Windows and use this to replace the hugs.exe file in the standard download, or make the following change in the Hugs source and recompile.
To compile the Hugs variant. Edit prelude.h and change the line that says:
#define MONAD_COMPS 0to:
#define MONAD_COMPS 1To confirm: just a one character change, 0 to 1. It's on about line 126.