[PLT announcement] PLT Scheme v299.200

From: Eli Barzilay (eli at barzilay.org)
Date: Tue Aug 9 02:20:47 EDT 2005

PLT Scheme v299.200 is now available from


THIS IS A v300 ALPHA RELEASE.  Teachers and students using DrScheme
with "How to Design Programs" should wait for the final v300 release,
which will occur close to a new semester.

* DrScheme's new "Debug" button provides limited debugging support.
  The programmer can pause a program in the definitions window,
  inspect local variables, set pause points, step past expressions,
  and change evaluation results.

  DrScheme's debugging support builds on MzTake, the scripted
  debugger, which is now included in the distribution.

* MzScheme supports reader extensions through #reader, and it provides
  readtables to customize the built-in reader. Structure printing can
  be customized through a `prop:writable' property.

* HtDCH USERS: the draw.ss teachpack has an entirely new interface.
  Canvas is now the class for drawing pictures, World is for animated
  worlds.  See doc.txt and the revised version of HtDCH.

* New "Java+dynamic" ProfessorJ language improves interoperability
  between Scheme and Java; details to appear at OOPSLA'05.

* FrTime has been refined significantly, with several important bug
  fixes and performance enhancements.

The v300 series (including v299.200) is incompatible with the v200
series.  The most significant incompatibilities include (1) support
for Unicode breaks old programs that treat characters as bytes or
pathnames as strings; (2) case-sensitivity is now the default; and (3)
the built-in exception hierarchy has been revised.

Fdeeback Wlecome
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                  http://www.barzilay.org/                 Maze is Life!

Posted on the announce mailing list.