Racket v8.9

Racket version 8.9 is now available from download.racket-lang.org

As of this release:

• The HtDP student languages come with checked signatures. Programmers can express signatures in a formal notation, and these signatures are checked at run-time (in a performance-neutral manner). The addition of this formal language associates meaning with several names that had no meaning before. — This feature is experimental, and we may amend or retract it later. (cf.docs.racket-lang.org/htdp-langs/beginner-abbr.html)

• Switching into and out of dark mode is handled better on Mac OS and Linux.

• Racket uses Unicode 15.0 for character and string operations.

• The racket/hash-code library provides support for combining hash codes. (cf.docs.racket-lang.org/reference/Equality.html)

• A language module can have a configure-expand submodule that is dynamically required to configure a parameterization before expansion of another module. (cf.docs.racket-lang.org/reference/running-sa.html)

• stream-cons supports multiple values. (cf.docs.racket-lang.org/reference/streams.html)

• unit/c subcontracts may depend on bindings from any imported or exported signature. Additionally, bindings’ contracts are enforced within subcontracts, and violations blame the contract itself (like ->i). (cf.docs.racket-lang.org/reference/unitcontracts.html)

• racket/class provides the dynamic-instantiate procedure for instantiating a class with a dynamic list of by-name initialization arguments. (cf.docs.racket-lang.org/reference/objcreation.html)

• TCP output block buffering implies TCP_NODELAY. (cf.docs.racket-lang.org/reference/tcp.html)

• Submodules and Check Syntax require arrows work better together.

• Typed Racket’s shallow check generation is improved.

• Many other improvements and bug fixes are included!

Thank you

Thank you to the people who contributed to this release:

Alex Harsányi, Alex Knauth, Alexis King, Ben Greenman, Bert De Ketelaere, Bob Burger, Bogdan Popa, Cadence Ember, D. Ben Knoble, Denis Hirn, dr-neptune, Eli Barzilay, Fred Fu, Gustavo Massaccesi, J. Ryan Stinnett, Jack Firth, Jamie Taylor, Jesse Alama, Jin-Ho King, John Clements, Lazerbeak12345, Mark Hedlund, Masaya Tojo, Matthew Flatt, Matthias Felleisen, Mike Sperber, Philip McGrath, Robby Findler, Ryan Culpepper, Sam Phillips, Sam Tobin-Hochstadt, sarna, Shu-Hung You, Sorawee Porncharoenwase, Stephen De Gabrielle, sxzzsf, Tom Price, Yukai Chou, and Zach O’Brien.

Feedback Welcome