Racket

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• The raco setup command can generate markdown documentation, using the --doc-markdown option.
• The "#lang" teaching languages (BSL, ..., ISL+; plus DeinProgram) have reached parity with the ones chosen using the Language dialog, and are the recommended choice.
• DrRacket's background expansion disables errortrace annotations, for faster syntax checking.
• The raco pkg install command includes new options that provide more install-time configuration flexibility: --adjacent-deps, --destdir, and --attach, and a refined --skip-installed.
• The ffi/unsafe/runtime-lib library provides a define-runtime-lib mechanism similar to define-runtime-path, allowing location of libraries located relative to a source file.
• The prompt-tag/c contract generator no longer performs checking on call/cc when the #:call/cc option is not present.
• The impersonate-prompt-tag function takes an additional argument that allows checking and update of results for composable continuations.
• The error-syntax->srcloc-handler parameter provides control over the mapping from syntactic forms to source locations for error handling.
• Uses of (tcp-listen 0) will retry when it fails with "address in use".
• The racket/base module requires fewer internal modules and instantiations.
• The file/zip package provides a new mechanism for greatly increased control over zip file generation, allowing in-memory file sources and per-file compression control.

The following people contributed to this release:

Alex Knauth, Alexander Shopov, Aris Spathis, Bert De Ketelaere, Bob Burger, Caleb Mazalevskis, Cameron Moy, Geoffrey J. Teale, Gustavo Massaccesi, Hannes Braun, Jade Sailor, Jason Hemann, Jens Axel Søgaard, John Clements, Jordan Johnson, Matthew Flatt, Matthias Felleisen, Mike Sperber, Nathan Dykman, Noah Ma, Philip McGrath, Robby Findler, Romeo Ahmed, Sam Tobin-Hochstadt, Shu-Hung You, Stefan Schwarzer, Stephen De Gabrielle, and Wing Hei Chan.

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• The match form checks that when non-linear patterns (patterns where the same variable is used multiple times) are used with ..., the two parts of the matched value actually are equal. Additionally, match rejects non-linear patterns where one use of the variable is used with ... and another is not. This repair could cause existing code to fail.
• Typed Racket's types for the asin and acos procedures correctly handle situations where the function produces a complex number, avoiding unsound results that were previously possible. This repair could cause existing code to fail at compile time.
• The #%foreign-inline core syntactic form provides unsafe access to facilities provided at the linklet layer by a Racket implementation. This means that any code that handles all core forms by enumeration will need to be updated.
• Unicode 17.0 is used for character and string operations.
• This release includes internal support for a more static "ffi2" foreign interface (to be used in a future package).
• The terminal-file-position function counts bytes written to ports connected to a terminal, such as stdin and stderr.
• Cross-phase persistent modules allow more types of quoted data.
• The implementations of member, memw, when, unless, let/ec, and cond are rewritten to use only racket/kernel syntax
• The impersonator-property-predicate-procedure? function identifies procedures created by make-impersonator-property.
• In Typed Racket, polymorphic struct types are printed using type arguments (e.g., (Array Byte)) rather than exposing an internal representation.
• The stepper's display of numbers better matches the language settings.
• Scribble documents that do not use the Racket-manual style get an initial-scale of 1.0, instead of the manual style's 0.8, but this can be configured using the initial-scale property.
• By default, margin notes appear inline for narrow displays in all styles, not just in the Racket-manual style.
• Big-bang programs distributed as .dmg files correctly handle the close-on-stop feature.
• There are many other repairs and documentation improvements!

The following people contributed to this release:

Alexander Shopov, Alexis King, Asilo, Bert De Ketelaere, Bob Burger, Bogdan Popa, Chung-chieh Shan, François-René Rideau, Gustavo Massaccesi, Ilya Klyuchnikov, Jade Sailor, Jamie Taylor, John Clements, Jonathan Simpson, LS_Hower, Matthew Flatt, Matthias Felleisen, Mike Sperber, Pavel Panchekha, Philippe Meunier, RMOlive, Robby Findler, Roman Klochkov, Sam Tobin-Hochstadt, Shu-Hung You, Stephen de Gabrielle, Tejas Sanap, Vincent Lee, and Wing Hei Chan.

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• Documentation organization and navigation can be specialized by language family, to allow users to interact with documentation in a way that is tailored to that language family. This is currently used by Rhombus.
• The for form and its variants accept an #:on-length-mismatch specifier. 3.18 Iterations and Comprehensions: for, for/list, ...
• DrRacket improves the GUI for choosing color schemes.
• DrRacket has curved syntax arrows. The degree of curvature indicates the relative left- or right-displacement of the arrow's target.
• DrRacket's "Insert Large Letters" uses characters that match the comment syntax of the buffer's language, making it useful (and fun!) in Rhombus.
• The exn-classify-errno maps network and filesystem error numbers on various platforms to posix-standard symbols, to enable more portable code. 10.2 Exceptions
• The behavior of Racket BC on certain character operations (most notably eq?) is changed to match that of Racket CS, with a small performance penalty for these operations for BC programs. 19 Performance 1.5 Implementations
• The make-struct-type procedure can inherit the current inspector using a 'current flag. This is the default behavior, but there are situations in which it's not possible to refer to the current inspector. 5.2 Creating Structure Types
• Bundle configurations can better control the conventions for locating shared object files with the --enable-sofind=<conv> flags.
• The system-type function can report on platform and shared-object-library conventions with new flags. 15.8 Environment and Runtime Information
• The openssl/legacy library makes it possible to access OpenSSL's built-in "legacy" provider, to get access to insecure and outdated algorithms. OpenSSL: Secure Communication
• Typed Racket improves expected type propagation for keyword argument functions.
• There are many other repairs and documentation improvements!

The following people contributed to this release:

Alexander Shopov, beast-hacker, Bob Burger, Brad Lucier, Cadence Ember, David Van Horn, evan, François-René Rideau, Gustavo Massaccesi, Jacqueline Firth, Jade Sailor, Jason Hemann, Jens Axel Søgaard, John Clements, Jonas Rinke, Matthew Flatt, Matthias Felleisen, Mike Sperber, Noah Ma, Pavel Panchekha, Rob Durst, Robby Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Stephen De Gabrielle, and Wing Hei Chan.

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• Racket supports parallel threads. For more information see the new blog post on the topic.
  • Parallel threads can be created using the #:pool argument to thread creation.
  • Threads created with #:keep set to 'results will record their results for later retrieval with thread-wait.
• The black-box wrapper prevents the optimizing compiler from optimizing away certain computations entirely. This can be helpful in ensuring that benchmarks are accurate.
• The decompile-linklet function can map linklets back to s-expressions.
• When using BC Racket, the processor-count function is changed to always return the parallel count.
• We now distribute "natipkg" packages for AArch64, useful for package-build and package-testing infrastructure.
• Check Syntax tracks identifiers more deeply nested in the "origin" field of syntax objects.
• The math library includes Weibull distributions.
• There are many other repairs and documentation improvements!

The following people contributed to this release:

Alexander Shopov, Anthony Carrico, Bert De Ketelaere, Bogdan Popa, Cadence Ember, David Van Horn, Gustavo Massaccesi, Jade Sailor, Jakub Zalewski, Jens Axel Søgaard, jestarray, John Clements, Jordan Johnson, Matthew Flatt, Matthias Felleisen, Mike Sperber, Philip McGrath, RMOlive, Robby Findler, Ruifeng Xie, Ryan Culpepper, Sam Phillips, Sam Tobin-Hochstadt, Sebastian Rakel, shenleban tongying, Shu-Hung You, Stephen De Gabrielle, Steve Byan, and Wing Hei Chan.

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• The racket-lang.org website no longer distributes Racket BC bundles, but it includes pre-built bundles for two flavors of ARM linux, AArch64 and 32-bit ARMv6 VFP.
• XML structures are serializable.
• Scribble's HTML generation conforms better to modern standards.
• Racket uses Unicode 16.0 for character and string operations.
• The redex-check default generation strategy always uses random generation to supplement the enumerator.
• DrRacket supports the use of shift-tab to go backward to previous indentation positions.
• The macro stepper supports the string-constants library, allowing internationalization of the stepper itself.
• The struct form supports #:properties prop-list-expr, making it more convenient to attach multiple property values to a structure type.
• Build-system improvements support containers registered at Docker Hub to build for all platforms that have downloads from the main Racket download site; improvements also support Unix-style builds for Mac OS in the style of MacPorts.
• The expt function produces a more accurate result when its first argument is a flonum and its second argument is an exact integer that has no equivalent flonum representation than it did in prior versions.
• TCP ports use SO_KEEPALIVE correctly.
• Unsafe code can use “uninterruptible mode” instead of “atomic mode” to allow futures to run concurrently while preventing interruptions from other threads.
• The net/imap library supports IMAP's move operation.
• There are many other repairs and documentation improvements!

The following people contributed to this release:

Bob Burger, Bogdan Popa, Brad Lucier, Carl Gay, Chloé Vulquin, D. Ben Knoble, Gustavo Massaccesi, Jacqueline Firth, Jade Sailor, Jarhmander, Jason Hemann, Jens Axel Søgaard, Joel Dueck, John Clements, jyn, Jörgen Brandt, Mao Yifu, Marc Nieper-Wißkirchen, Matthew Flatt, Matthias Felleisen, Mike Sperber, Noah Ma, paralogismos, Pavel Panchekha, Philip McGrath, Robby Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Shalok Shalom, Stephen De Gabrielle, Steve Byan, Vincent Lee, Wing Hei Chan, and ZC Findler.

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• 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!

The following people contributed to this release:

Alexander Shopov, Andrei Dorian Duma, Bert De Ketelaere, Bob Burger, Bogdan Popa, Bogdana Vereha, Cameron Moy, Chung-chieh Shan, Cutie Deng, D. Ben Knoble, Dario Hamidi, Dominik Pantůček, Gustavo Massaccesi, halfminami, Jacqueline Firth, Jason Hemann, Jens Axel Søgaard, Joel Dueck, John Clements, Jordan Harman, Marc Nieper-Wißkirchen, Matthew Flatt, Matthias Felleisen, Mike Sperber, Noah Ma, owaddell-ib, Philippe Meunier, Robby Findler, Ryan Culpepper, Ryan Ficklin, Sam Phillips, Sam Tobin-Hochstadt, Shu-Hung You, sogaiu, Sorawee Porncharoenwase, Stephen De Gabrielle, Vincent Lee, and Wing Hei Chan.

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• Racket has expanded support for immutable and mutable treelists:
  • A variety of new treelist utility functions are available: treelist-filter, treelist-flatten, et cetera.
  • The mutable-treelist-prepend! function allows prepending to mutable treelists.
  • Mutable treelists are serializable.
• The serialize-structs module allows the minimization of dependencies by providing only a handful of core forms.
• The flbit-field function allows access to the binary representation of IEEE floating-point numbers.
• The top-left search box in the documentation works once more.
• The XML reader is 2-3x faster on inputs with long CDATA and comments, and avoids some internal contract checks to obtain a 25% speedup on large documents generally.
• The pregexp syntax includes "\X" to match a grapheme cluster), following Perl and PCRE.
• The read-json* and write-json* functions allow customization of the Racket representation of JSON elements, eliminating the need for a separate "translation" pass.
• Racket has new port I/O functions:
  • The open-input-nowhere function creates an empty input port.
  • The pipe-port? function makes it possible to determine whether a port is created by make-pipe.
  • The port-file-stat function allows gathering information about the file that is the source or target of a file-stream port.
• A revised representation of pointers improves the performance of foreign function calls. As a result, ptr-ref and ptr-set! are substantially faster.
• In anticipation of the fifteenth RacketCon, the fifteenth function returns the fifteenth element of a list.
• Racket has an improved multi-line convention for error messages.
• The db library allows prepare on virtual statements.
• The student-t distribution is part of the math/distributions library.
• Expeditor supports customizing the prompt, using the #:prompt keyword argument to call-with-expeditor.
• There is a guide to adding internationalization for a new (human) language.
• Optimizations to racket/profile improve asymptotic speed for very large call graphs.
• The #lang htdp/asl language incorporates Graphical Debugger support.
• There is lots of new documentation, and many defects repaired!

The following people contributed to this release:

a11ce, Alex Knauth, Alexander Shopov, Alexis King, Andrew Mauer-Oats, Anthony Carrico, Bert De Ketelaere, Bob Burger, Bogdan Popa, D. Ben Knoble, David Van Horn, Gustavo Massaccesi, halfminami, Hao Zhang, Jacqueline Firth, Jinser Kafka, JJ, John Clements, Jörgen Brandt, Kraskaska, lafirest, Laurent Orseau, lukejianu, Marc Nieper-Wißkirchen, Matthew Flatt, Matthias Felleisen, mehbark, Mike Sperber, Noah Ma, Onorio Catenacci, Oscar Waddell, Pavel Panchekha, payneca, Robby Findler, Sam Phillips, Sam Tobin-Hochstadt, Shu-Hung You, Sorawee Porncharoenwase, Stephen De Gabrielle, Wing Hei Chan, Yi Cao, and ZhangHao.

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• Documentation search results are ordered, with visual cues indicating what their source is (core, main-distribution, etc.). These results are also grouped by language family (Racket, Rhombus, etc.). (See https://docs.racket-lang.org/search/index.html?q=second .)
• DrRacket offers to restore previously open files when starting, which can be made the default.
• In DrRacket, Picts can be saved by right-clicking.
• raco pkg introduces the uninstall command as the opposite of install. The remove name for this functionality is retained for compatibility. (See https://docs.racket-lang.org/pkg/cmdline.html#%28part._raco-pkg-uninstall%29 .)
• raco pkg improves the handling of --clone and --unclone. (See https://docs.racket-lang.org/pkg/cmdline.html#%28part._raco-pkg-update%29 .)
• iOS is a compilation target, distinct from macOS.
• Racket supports falling back to IPv4 during hostname resolution when IPv6 fails.
• Memory allocated using the ffi/unsafe library can be initially zeroed, using the 'zeroed-atomic and 'zeroed-atomic-interior flags. (See https://docs.racket-lang.org/foreign/foreign_pointer-funcs.html#%28idx._%28gentag._11._%28lib._scribblings%2Fforeign%2Fforeign..scrbl%29%29%29 .)
• Many other bugs are fixed and documentation has been improved!

The following people contributed to this release:

Alec Mills, Alex Knauth, Alexander Shopov, Ashlynn Anderson, Ashton Wiersdorf, Ben Greenman, Benjamin Yeung, Bob Burger, Bogdan Popa, Breck Yunits, Carl Gay, Claes Wallin (韋嘉誠), CooperCorad, Crystal Jacobs, D. Ben Knoble, Dexter Santucci, Eduardo Cavazos, Emil Szpakowski, evelynmitchell, Greg Hendershott, Gunnar Ahlberg, Gwen Weinholt, Idiomdrottning, Ikko Eltociear Ashimine, Jacqueline Firth, Jarhmander, Jay McCarthy, Jens Axel Søgaard, Jimmy McNutt, jinser, Jinser Kafka, John Clements, lukejianu, Marc Nieper-Wißkirchen, Matej Fandl, Matthew Flatt, Matthias Felleisen, Michael Ballantyne, Mike Sperber, olopierpa, Paul Morris, Phil Nguyen, Philip McGrath, Robby Findler, Ronald Garcia, Ryan Culpepper, Sam Phillips, Sam Tobin-Hochstadt, Siddhartha Kasivajhula, Sorawee Porncharoenwase, Stephen De Gabrielle, Syntacticlosure, Taylor Allred, Tomas Fabrizio Orsi, Wing Hei Chan, and Yafei Yang.

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• 64-bit ARM Windows is one of the standard pre-built downloads.

• The compiler/demod language integrates demodularization into the program rather than an external tool. Using the language approach cooperates with other Racket tools and allows demodularization to be used on libraries. Additionally, demodularization handles submodules and can prune definitions, significantly shrinking the size of some programs.

• The contract-in form enables contracts to be specified in an importing module.

• The #%declare form supports the #:flatten-requires and #:unlimited-compile keywords

• Identifiers such as case-λ, match-λ and λ are equivalent to their Latin-alphabet equivalents (case-lambda, match-lambda, and lambda) in more contexts, including uses of match.

• The hash-filter function allows the use of a predicate to select a sub-table of a hash table.

• The module browser can perform filtering on submodules.

• The raco test command-line form respects the current-test-invocation-directory parameter, and shows well-formed module paths in its output.

• Racket CS allows the use of in-memory boot files.

• The raco/testing collection brings together a variety of testing- related functions and forms.

• This release also includes many bug-fixes and documentation updates!

• NOTE: This release (and version 8.13) have a known build problem that affects the builtpkgs source bundle on Windows. In order to avoid this problem, use a pre-built bundle or build using a source bundle other than the "builtpkgs" one. Nightly builds do not suffer from this problem.

The following people contributed to this release:

Alex Knauth, Alexander Shopov, Ben Greenman, Bert De Ketelaere, Bob Burger, Bogdan Popa, Cadence Ember, Carl Gay, D. Ben Knoble, Gregory Rosenblatt, Gustavo Massaccesi, John Clements, John Sullivan, Jordan Johnson, luistung, Matthew Flatt, Matthias Felleisen, Noah Ma, Philip McGrath, Robby Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Sergey Fedorov, Sorawee Porncharoenwase, Wing Hei Chan, and ZhangHao.

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• The racket/treelist and racket/mutable-treelist libraries provide list-like containers that support many operations in effectively constant time, including appending and extracting sub-lists without mutating the given list. Treelists are implemented as RRB Vectors, invented by Stucki, Riompf, Ureche, and Bagwell.

(see https://docs.racket-lang.org/reference/treelist.html#(part._treelist) and https://dl.acm.org/doi/abs/10.1145/2784731.2784739 )

• The hash-filter-keys and hash-filter-values functions allow users to filter hashes using a predicate on either keys or values.

(see https://docs.racket-lang.org/reference/hashtables.html#%28def._%28%28lib._racket%2Fhash..rkt%29._hash-filter-keys%29%29 )

• The vector-extend and vector*-extend functions provide a way to pre-populate the prefix of a newly allocated vector using the elements of an existing vector.

(see https://docs.racket-lang.org/reference/vectors.html#%28def._%28%28lib._racket%2Fvector..rkt%29._vector-extend%29%29 )

• Command-line raco setup, package update, and package installation use terminal control (when available) to show what they are working on more compactly and with a progress bar.

• Racket v8.13 uses Unicode 15.1 for character and string operations.

• Machine-specific cross-module optimization allows improved support for static generation of foreign-function bindings.

• The scribble/acmart language uses v2.01, which avoids errors concerning the hyperref package in some latex installations.

The following people contributed to this release:

Alec Mills, Ben Greenman, Bob Burger, Bogdan Popa, dr-neptune, Fred Fu, Gustavo Massaccesi, Jason Hemann, Jay McCarthy, John Clements, Jordan Johnson, Justin Dhillon, Mao Yifu, Matias Eyzaguirre, Matthew Flatt, Matthias Felleisen, Mike Sperber, olopierpa, Oscar Waddell, Pavel Panchekha, Philip McGrath, Robby Findler, Sam Phillips, Sam Tobin-Hochstadt, Siddhartha Kasivajhula, Sorawee Porncharoenwase, Stephen De Gabrielle, Tim Standen, William E. Byrd, and Wing Hei Chan.

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