ALE 3.2 beta available

[Gerald Penn]

Hello,

  ALE 3.2 beta is now available from the ALE homepage:

http://www.sfs.nphil.uni-tuebingen.de/~gpenn/ale.html

In this version:

- ALE is faster (again), both at compile-time and run-time,
- A new parsing compilation algorithm (Empty-First-Daughter closure),
  which:
     * corrects a long-standing problem in ALE with combining empty
       categories - EFD closure closes the phrase structure rules of a
       grammar under prefixes of empty category daughters, so any
       permutation of empty categories can, in principle, be combined
       to form a new empty category;
     * corrects a problem that non-ISO-compatible Prologs, including
       SICStus Prolog, have with asserted predicates that results in
       leftmost empty category daughters not being able to combine
       with their own outputs;
     * allows parsers to establish a precondition that rules only need
       to be closed with non-empty leftmost daughters at run-time -
       this allows ALE, at each step in its right-to-left pass
       throught the string, to copy all of the edges in the internal
       database back onto the heap before they can be used again, and
       thus reduces edge copying to a constant 2 copies per edge for
       non-empty edges (edges with different left and right
       nodes). Keeping a copy of the chart on the heap also allows for
       more sophisticated indexing strategies that would otherwise be
       overwhelmed by the cost of copying the edge before
       matching. This puts to rest the misconception that Prolog-based
       parsers are necessarily inefficient because of copying
       overhead.
- Shallow cuts (if-then-else predicates) have been added to the
  definite clause language
- Faster extensionalisation code, particularly with grammars that have
  few or no extensional types,
- Faster subsumption checking code for chart edges,
- ALE Source-level Debugger 3.0 beta, which has been integrated with
  the new SICStus 3.7 source-level debugger,
- More compile-time error and warning messages,
- Several bug corrections,
- An updated user's manual,
- An SWI Prolog port.

Regards,
Bob Carpenter and Gerald Penn