Archived News: 2007-03

I have eliminated my "corrections" to the Mercury
extras xml library (I had an outdated
version of the library as outlined in the
2007-03-18 news post, so
my corrections were redundant the the Mercury team's).
At the same time, I have moved my XML enhancements
into the utils library and promoted
the doug_graph module from alpha; it is
now also included in utils.

18:

A new library and several improvements can be found in
the shared repository:

• The xml library provided in the Mercury
  extras distribution is out-of-date; it no
  longer compiles. I have fixed the compile errors and added
  several modules (to assist in XML transformations and
  pretty-printing) and tests.

  Update 2007-03-28:

  I was in error in the above item: my
  copy of the xml library provided by the
  Mercury team was out of date; the version
  supplied with the extras
  distribution by the Mercury team is
  working correctly.

  This means my fixes to the xml library are
  redundant, so I withdraw them. The extended
  functionality, however, I do continue to find
  (very) useful, so I am moving these
  enhancements as an xml library under
  the utils umbrella.

• Several improvements are available for
  qcheck2:

  
  
  1. 
     

     I have modified the qcheck2 library so
     that it now uses the RNG protocol as proposed in the
     Mercury users' maillist. I have also modified the
     reporting feature to accept a polymorphic type for
     module.predicate unit tests ... this improvement
     'upgrades' qcheck2 to be an independent
     library (qcheck was also an independent
     library).

  2. The program qcpt that generates the
     module.predicate test points for a system has also
     been updated to use the new qcheck2
     reporting protocol. qcpt is bundled
     with ltq.



• 
  

  I have entirely changed the utils library:

  1. Although useful for a small number of repetitions,
     the peano module becomes unweildly for
     large cycles (1,000,000 is represented as 1,000,001
     cons cells!). So, I have discarded it in favor of a
     slightly more sophisticated counting algorithm (where
     1,000,000 is represented by 7 cons cells) in the
     utils.series module that now also includes
     loop abstraction with func unfold/3 and
     pred svunfold/6 (the latter being used when
     one must also update a dependent state variable).

  2. Julian Fondrant on the Mercury Users maillist
     proposed a RNG typeclass and protocol, and published a
     module implementation using the tausworthe3 algorithm.
     I have incorporated this module (as
     utils.random) with a simplified
     façade and other minor corrections.

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