From: Eli Barzilay <firstname.lastname@example.org> To: email@example.com Subject: [PLT announcement] PLT Scheme v4.2 Date: Mon, 01 Jun 2009 14:24:45 -0400 PLT Scheme version 4.2 is now available from http://plt-scheme.org/ Internally, this version includes a conversion from C++ to Scheme for part of the GUI toolbox --- specifically, 25k lines of code that implement the general text and pasteboard editor. This conversion is a start on a larger reimplementation of the GUI toolbox. Although we believe that this change will help make PLT Scheme better in the long run, we must expect bugs in the short term due to porting errors. Users should therefore be aware of the change, even though the new implementation is meant to behave the same as previous versions. * A new statistical profiler is now available; see the "profiler" manual for more information. Currently, the profiler supports only textual output, but future plans include a GUI interface and DrScheme integration. * The `world’ teachpack is now deprecated. Its replacement `universe’ has a new interface that uses strings instead of symbols and characters. * Web-server: Native continuations in the stateless servlet language support capturing continuations from untransformed contexts; soft state library for stateless servlets. * DrScheme’s Stepper can now jump to a selected program expression. * New in `scheme/base’: `hash-has-key?’, `hash-ref!’, `in-sequences’, `in-cycle’. New in `scheme’: `count’, `make-list’ (from `scheme/list’), `const’ (from `scheme/function’). * Some performance improvements, including faster start-up for small programs. The latter is a result of delaying module invocations at higher phases (compile time, meta-compile time, etc.) until compilation is demanded at the next lower phase; this on-demand instantiation is per-phase, as opposed to per-module within a phase. [Note that mirror sites can take a while to catch up with the new downloads.] Feedback Welcome, -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://www.barzilay.org/ Maze is Life!