PLT Scheme v4.1

posted by Eli Barzilay

PLT Scheme version 4.1 is now available from http://plt-scheme.org/

• DrScheme changes:
  • The Module language now has an automatically inserted #lang declaration, so the interactions window is available right away for new windows.
  • Searching is now interactive (see the manual for details).
  • Memory limits are now enabled by default.

• Typed Scheme supports a novel type checking mechanism for homogeneous and heterogeneous variable-arity function definitions and applications.

• Redex (a domain-specific language for testing operational semantics) is now included in the distribution. See also [redex.plt-scheme.org](http://redex.plt-scheme.org/).

• Lots of improvement to the documentation, including: better searching, table-of-contents, and language-sensitive help (in the teaching languages).

• The world.ss teachpack no longer supports end-of-time, only stop-when.

• MzScheme has now a logging facility, search the documentationfor “logger” for more details.

• Bug fixes:
  • begin in R5RS (and derived languages),
  • #lang planet,
  • eval works with phases.

Feedback Welcome.