Stratego Release 063

New features

• BuildSplit^?
• MatchProject^?

Release Announcement

Version 0.6.3

 released: November 26, 2001

SUMMARY OF CHANGES

 (with respect to release 0.6)

 * BuildSplit syntax generalizes split
 * MatchProject syntax generalizes projection
 * New library strategies
 * Tracing of evaluation
 * Several bug repairs
 * Anonymous CVS checkout is possible again
 * Website runs new twiki

INSTALLATION NOTE

 * Configuration with the default prefix flag does not work properly.
   If installing at /usr/local, configure explicitly as follows:

      configure --prefix=/usr/local

CONTRIBUTIONS

 * Bug reports by Otto Skrove Bagge, Robert Feldt (configuration),
   Merijn de Jonge (strings & #), Hedzer Westra
 * Bug repairs by Merijn de Jonge (strings & #)
 * Library contributions by Otto Skrove Bagge (insert)
 * CVS support: Henk van Lingen
 * Web hosting: Henk Penning

LANGUAGE

 * Term patterns can contain strategy applications <s>. 

 * Build-Split patterns simplify wrapping some complex constructor pattern
   around a term. For instance, split(f,g) can now be written as
   !(<f>,<g>), and this generalizes to arbitrary build patterns.

 * Match-Project patterns simplify projection of sub-terms. A strategy
   application <s> inside a match pattern selects the corresponding sub-term
   and applies s to it. For example, instead of writing 
   \ Typed(Var(x),_) -> x \ it is now possible to write ?Typed(Var(<id>),_)
   This feature can also be used to perform tests on subterm in a
   match pattern, e.g., the pattern ?[x | <not([])>] binds the head of a list
   to x, checks that the tail is not empty and produces the tail as
   result.

COMPILER

 * Added compile time option to generate code to trace strategies
   - --trace-all: trace all strategies
   - -t f: trace strategy f
   - Note: -t option does not work properly yet.

 * Optimization is set to O2 by default (used to be O4). The higher
   optimization level (which comes down to inlining functions in addition
   to the O2 optimizations) seems to produce faulty code on some
   machine/compiler combinations. Optimization can be increased by
   passing the option -CI "O3" to SC. However, it seems appropriate to
   leave inlining decisions to SC.

 * Repair in implementation of dynamic rules; added rule stamp in order
   to record to which rule the information belongs.

 * Repair of compilation of overlays

LIBRARY

 * Repair of term explosion for strings (Merijn de Jonge). Quoted
   identifiers (strings) can now be used as constructor symbols.
   Not yet supported in signatures.
 * Type annotations added to strategy operators with higher-order
   arguments.
 * Numerous small refactorings.
 * Some new tests
 * New
    - occurrences(s): all occurrence for which s succeeds
    - om-occurrences(s): outermost occurrences only
    - collect-all(s): collect all occurrences
    - collect-om(s): collect outermost occurrences only
 * Obsolete: 
    - collect-kids/1 -> crush/3

DISTRIBUTION

 * The Stratego CVS repository is accessible again. To check out the contents
   of the repository type:

      cvs -d :pserver:anonymous@cvs.cs.uu.nl:/data/cvs-rep checkout Stratego

   Thanks to Henk van Lingen for setting up the cvs server.

 * If you would like to get involved in development of the compiler or library,
   it is also possible to obtain write access to the repository. Contact me
   if you're interested.

WEBSITE

 * The twiki running the website has moved from losser to the production server
   of the Utrecht University CS department. Thanks to Henk Penning for making 
   this possible. Individual pages are now bookmarkable under the 
   stratego-language.org URL. Access control has been improved. Users need to 
   re-register to enter a password.