Racket v7.1

posted by Vincent St-Amour

Racket version 7.1 is now available from http://racket-lang.org/

• Although it is still not part of this release, the development of Racket on Chez Scheme continues. We still hope and expect that Racket-on-Chez will be ready for production use later in the v7.x series, perhaps mid–2019.

• Trackpad scrolling works in more reliably in some Windows and Linux/Unix environments.

• New users of DrRacket will open files into new tabs (by default).

• The teaching languages support the unicode character for lambda. The teaching unit test framework no longer stops testing when a tested expression signals an error.

• A refinement to error reporting for compile-time code helps clarify when an syntax error is likely due to an earlier unbound identifier (because the unbound-identifier error otherwise must be delayed, in case a definition appears later).

• A ++lang <lang> flag for raco exe simplifies the creation of executables that dynamically load #lang <lang> modules at run time.

• Typed Racket adds types for mutable and immutable vectors: (Mutable-Vectorof T), (Immutable-Vectorof T), (Immutable-Vector T), and (Mutable-Vector T). The new types are subtypes of the existing Vectorof and Vector types. The return types of a few standard vector functions use the new, more specific, types. When an immutable vector flows from untyped code to typed code, Typed Racket may be able to check the vector with a flat contract.

• The hashing functions sha1-bytes, sha224-bytes, and sha256-bytes are added to racket/base.

• curry from racket/function supports currying functions with keyword arguments, and procedure-arity and procedure-keywords return the correct result when applied to curried functions.

• Slideshow supports widescreen mode (finally!). Implement widescreen slides using slideshow/widescreen or provide the --widescreen command-line flag to Slideshow. Combine --widescreen with --save-aspect to make widescreen mode the default in your installation.

• Racket supports FreeBSD/aarch64.

• Various improvements and additions were made to the DeinProgramm teaching languages and their documentation.

The following people contributed to this release: Akihide Nano, Alex Harsányi, Alex Knauth, Alexander McLin, Alexis King, Andrew Kent, Ben Greenman, Bruno Cuconato, Chongkai Zhu, Claes Wallin, David Benoit, Gary F. Baumgartner, Gustavo Massaccesi, Jay McCarthy, Jens Axel Søgaard, Jérôme Martin, John Clements, Jordan Johnson, Kimball Germane, Leif Andersen, Matthew Butterick, Matthew Flatt, Matthias Felleisen, Mike Sperber, Milo Turner, myfreeweb, Oling Cat, Paulo Matos, Philip McGrath, Robby Findler, Roman Klochkov, Ryan Culpepper, Sam Caldwell, Sam Tobin-Hochstadt, Shu-Hung You, Stephen Chang, Tong-Kiat Tan, Vincent St-Amour, Winston Weinert, and yjqww6.

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