Racket for Mac

To restore packages installed for a previous version of Racket, use DrRacket's File > Package Manager > Copy from Version or at a command line use raco pkg migrate.

• The new `drracket-core` package provides a version of drracket with a smaller set of dependencies.
• Typed Racket has support for treelists.
• The package manager computes checksums for packages when required, allowing the use and automatic upgrade of packages without them.
• The `bitwise-first-bit-set` function returns the smallest bit that is set in the twos-complement representation of the given number.
• The updated `dynamic-require` function makes it easier to use syntax bindings by allowing a syntax-thunk (or 'eval) to be used for them.
• The `error-module-path->string-handler` parameter allows the customization of the display of module-paths in error messages.
• Precision of certain numeric functions (`sin`, `cos`, and others) is improved on Windows platforms by using the MSVCRT/UCRT libraries.
• The `string-append` function has improved performance and reduced memory use for long lists of strings in the Racket CS implementation. Differences are clearly noticeable for lists of length 1 million.
• TCP ports use `SO_KEEPALIVE`, instructing the kernel to send periodic messages while waiting for data to check whether the connection is still responsive.
• Racket code using a terminal in Windows can receive mouse events as virtual terminal characters after using SetConsoleMode. (This is also already possible on macOS and Linux.) See the tui-term package for related example code.
• The `#:replace-malformed-surrogate?` keyword can be used to specify a replacement for malformed unicode surrogates in JSON input
• The http-client module no longer sends "Content-Length: 0" for requests without a body.
• The demodularizer (`compiler/demod`) can prune more unused assignments.
• Several judgment rendering forms in Redex are replaced by functions, allowing more convenient abstraction.
• When a distribution includes no teaching languages, DrRacket’s language-dialog configuration moves into the preferences dialog and the “Language” menu disappears.
• The math library has better support for block-diagonal matrices, including both Racket and Typed Racket.
• The math library contains improved implementations of acos and matrix-(cos-)angle.
• The stepper again works for `big-bang` programs.
• There are many other repairs and documentation imprevements!