22 Mar 2009

PLT Scheme v4.1.5

posted by Eli Barzilay

PLT Scheme version 4.1.5 is now available from http://plt-scheme.org/

  • Web Server:
    • new URL-based dispatching library web-server/dispatch,
    • customizable continuation serialization policies for the stateless web language web-server/stuffers,
    • abstraction of serve/servlet to build simpler dispatchers web-server/servlet-env,
    • HTTP Digest authentication support web-server/http/digest-auth,
    • built-in cookie support in web-server/http/cookie and web-server/http/cookie-parse,
    • highlighting and pretty-printing of errors in Xexpr constructions,
    • load control dispatcher for limit concurrent sessions web-server/dispatchers/limit.
  • Scribble:
    • Literate programming is now available using the new scribble/lp language.
    • A new at-exp language makes it convenient to use the scribble reader’s @-expressions for general code.
    • The scribble/text preprocessor language has been extended to deal with indentation and other formatting issues.
    • The “scribble” command-line tool accepts a --pdf flag to render PDFs (via pdflatex).
  • DrScheme now provides feedback when PLaneT downloads and installs new packages.

  • Units & Contracts:
    • Elements of unit signatures can now be associated with contracts via the contracted signature form.
    • A contract combinator for units, unit/c, has been added.
    • The new with-contract form provides a nestable submodule contract boundary, protecting a group of definitions from the surrounding code with contracts.
    • The define/contract form has been reworked and new define forms have been added: define-struct/contract and define-unit/contract.
  • Language levels and teachpacks from the DeinProgramm project for the German textbook “Die Macht der Abstraktion” by Herbert Klaeren and Michael Sperber have been added.

  • Misc:
    • Typed Scheme now comes with several more pre-wrapped libraries, found in the typed collection.
    • The xml and html collections are now contracted.
    • Binding parsing in net/cgi now interacts with net/uri-codec’s configuration parameters.
    • DrScheme captures logging output.
    • Check syntax: it is now possible to tack arrows crossing the currently selected text.
    • New bitwise-bit-field function.
  • The usual pile of bugfixes. (Notable: scheme/package works, deflate compression fixed, DrScheme language dialog issue resolved, match fixes, Windows networking, and much more.)

[Note that mirror sites can take a while to catch up with the new downloads.]

Feedback Welcome.

nice. I’m new to scheme and using plt scheme to build a web prototype…

After years of C++, I must say I love the language and environment.

I really appreciate the work you guys put into this - will be nice to have the url aliasing of this release.

gord, 22 March 2009

We’re glad you like it! I’d be very interested to know any of the problems you do have with the Web framework, because I might be able to make it even better.

Jay McCarthy, 22 March 2009

Pretty cool stuff dude!

RT www.Privacy-Center.net

Harold Fowler, 22 March 2009

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