[plt-scheme] PLT Scheme v4.0

From: Stephen De Gabrielle (stephen at degabrielle.name)
Date: Thu Jun 12 03:58:02 EDT 2008

Well done!


On Thu, Jun 12, 2008 at 7:03 AM, Eli Barzilay <eli at barzilay.org> wrote:
> PLT Scheme version 4.0 is now available from
>     http://plt-scheme.org/
> This major new release offers many improvements over version 372, and
> we encourage everyone to upgrade.
>  * The PLT Scheme language now provides better syntax for modules,
>    better support for optional and keyword arguments to functions, a
>    more complete syntax for structure types, new syntax for list
>    comprehensions and iterations, a more complete and consistent set
>    of list operations, a more complete set of string operations, and
>    streamlined hash-table operations.
>  * The documentation has been re-organized and re-written.  New
>    tutorials and overviews offer a clearer introduction to Scheme and
>    PLT Scheme.
>  * New documentation tools help programmers create and install
>    documentation for libraries and Planet packages.  All installed
>    documentation can be read though the user's web browser, and even
>    searching within the browser works on local files.
>    The language for writing documentation is an extension of Scheme,
>    and document sources are linked to implementations through the
>    module system.  The module connection allows, for example,
>    reliable automatic hyperlinking of identifiers mentioned in
>    documentation to their specifications in other documentation.
>  * R6RS programs are supported in two ways: though the `plt-r6rs'
>    executable and through the `#!r6rs' prefix.  The latter allows an
>    R6RS library or program to serve as a PLT Scheme module.
>  * Legacy R5RS support is improved, partly through a separate
>    `plt-r5rs' executable.
>  * Pairs are immutable within the PLT Scheme language; mutable pairs
>    (which are the same as R6RS and R5RS pairs) are provided as a
>    separate datatype.  For more information, see
>      http://blog.plt-scheme.org/2007/11/getting-rid-of-set-car-and-set-cdr.html
>  * ProfessorJ uses a new and improved parser, it evaluates programs
>    faster, and it includes a Java-specific indenter.
>  * Testing frameworks for the HtDP and HtDC (ProfessorJ) teaching
>    languages have been unified.  Both support systematic unit testing
>    in a comprehensive fashion.  When programs lack tests, students
>    are asked to add test cases.  When all tests succeed, a simple
>    message says so; otherwise, a pop-up window (dockable) displays
>    URLs to the failed test cases and explains why the cases failed.
>  * Typed Scheme, a statically typed dialect of Scheme, is now
>    included with PLT Scheme.  While Typed Scheme is still in its
>    early stages of development, it supports modular programming with
>    types and full interaction with existing untyped code.  Safe
>    interactions between typed and untyped modules are enforced via
>    contracts.  Typed Scheme also features a novel type system
>    designed to accommodate Scheme programming idioms.  For more
>    information, see http://www.ccs.neu.edu/~samth/typed-scheme/ .
> Feedback Welcome,
> --
>          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
>                  http://www.barzilay.org/                 Maze is Life!
> _________________________________________________
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>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme



Stephen De Gabrielle
s.degabrielle at cs.ucl.ac.uk
Telephone +44 (0)20 7679 0693 (x30693)
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Project: Making Sense of Information (MaSI)

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