Hello, in StaticDTD we are moving to complete statical validness against a DTD. For a (compile time) function that uses our generic combinators, we can garuantee the following: - The content model for each element is enforced (this is done by checking a type-level determined finite automaton for each content model) - The attributes are validated (not so their values yet). The check function facilitates a type-level mergesort algorithm. We are using a HList like structure and so these garuantees also hold with higher order functions. The implementation can be found at http://m13s07.vlinux.de/darcs/StaticDTD/v2 It is a mess and all of the infrastructure around it is still missing, but it shows that the concept might work. We hope to have a well-working release in very few months. Some words about related work: - WASH/HTML [1] was the original inspiration for us. It checks proper nesting of elements, but not the content model. It is a HTML, not a 'all DTDs of XML' library - HaXml [2] has two modes: one with generic combinators, which are not type-safe in respect to a DTD, and one where validity is enforced by regex-like Haskell abstract data types. With them, pattern matching can be used. - HSXML [3] has generic combinators and checkes for some nesting-properties. - BinaryNumbers.hs [4] is a great type-level implemention of numeric calculation and we are using it in our library for defining complete order and enumerate the states of a DFA. As a side-effect of our work we hope to put the type-level functions in a small seperate 'type-level programming' library, for common use. Comments are very welcome. Marcel Manthe [1] http://www.informatik.uni-freiburg.de/~thiemann/WASH/#washhtml [2] http://www.cs.york.ac.uk/fp/HaXml/ [3] http://okmij.org/ftp/Scheme/xml.html#typed-SXML [4] http://okmij.org/ftp/Haskell/types.html#binary-arithm -- View this message in context: http://www.nabble.com/Progress-in-StaticDTD-tf4106801.html#a11678520 Sent from the Haskell - Haskell mailing list archive at Nabble.com.