Markup languages have recently regained popularity for two reasons.
One is document exchange, which is largely based on HTML, an instance of
SGML, and the other is for data exchange between programs, which is
often based on XML, which can be considered a simplified and
rationalised version of SGML.
James Clark's SP parser is a flexible SGML and XML parser.
Unfortunately it has some drawbacks. It is very big, not very fast,
cannot work under event-driven input and is generally hard to program
beyond the scope of the well designed generic interface. The generic
interface however does not provide access to the DTD, does not allow for
flexible handling of input or parsing the DTD independently of a
document instance.
The parser described in this document is small (less than 100 kBytes
executable on a Pentium), fast (between 2 and 5 times faster than SP),
provides access to the DTD, and provides flexible input handling.
The document output is equal to the output produced by xml2pl,
an SP interface to SWI-Prolog written by Anjo Anjewierden.
