26 Jan 2018

Racket v6.12

posted by Vincent St-Amour

Racket version 6.12 is now available from http://racket-lang.org/

Changed the way some unsafe operations are exposed via ffi/unsafe libraries to help smooth a future transition to a new runtime system.
The syntax-parse form supports unwinding side-effects when it backtracks, both explicitly with ~undo patterns and implicitly with the built-in managed state (using syntax-parse-state-ref, etc).
The db library supports SCRAM-SHA–256 authentication for backends running PostgreSQL 10 or later. Client support for SCRAM and other SASL mechanisms is provided by the new sasl library.
The lazy-require-syntax form supports lazy loading of macro transformers. Note that the macros must obey certain implementation constraints (see the lazy-require-syntax documentation).
Typed Racket no longer enforces types like (U String (Boxof String)) with the any/c contract. This fixes a type soundness issue, but may affect performance. Please submit a bug report if you find a program that runs significantly slower on v6.12 than earlier versions.
Typed Racket’s type instantiation (inst) uses Any for omitted type arguments, allowing APIs to add additional type variables to functions without breaking existing programs.
for/fold users can customize the final result of a loop’s computation using the #:result keyword.
The --deps option to raco test tests the packages the argument packages depends on, in addition to testing the packages themselves. For example, raco test -p --deps pkg1 pkg2 tests all files from pkg1, pkg2, and all of their dependencies.

The following people contributed to this release: Alexander Shopov, Alexis King, Andrew Gwozdziewycz, Andrew Kent, Ben Greenman, Chung-chieh Shan, Conor Finegan, Daniel Feltey, Daniel Mendler, Eric Dobson, Gabriel Ebner, Greg Cooper, Greg Hendershott, Gustavo Massaccesi, Huma Zafar, Jack Firth, James Bornholt, Jay McCarthy, John Clements, Kimball Germane, Leif Andersen, Matias Eyzaguirre, Matthew Butterick, Matthew Flatt, Matthias Felleisen, Michael Ballantyne, Mike Sperber, Milo Turner, Robby Findler, Rommel Martinez, Ryan Culpepper, Sam Tobin-Hochstadt, Shu-Hung You, Soulaïmane Sahmi, Spencer Florence, Stephen De Gabrielle, Vincent St-Amour, Wesley Kerfoot, and William G Hatch.

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