Racket v8.13

---

• 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.

---

Racket v8.12

---

• The "Die Macht der Abstraktion" language levels are no longer present,
  replaced by the "Schreibe dein Programm" language levels which have been
  available for several years. (see https://www.deinprogramm.de/sdp/ )

• The release fixes a problem with the binding structure of the for/fold
  form in the rare situation when an iteration clause identifier shadowed
  an accumulator identifier. This change may break code that depends on
  the old binding structure. (see https://docs.racket-lang.org/reference/for.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._for%2Ffold%29%29 )

• Racket automatically sets the close-on-exec flag when opening a file, on
  systems where this is available. This change lowers the cost of avoiding
  problems that can occur when file descriptors become accidentally shared
  between processes. (see https://docs.racket-lang.org/reference/file-ports.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._open-input-file%29%29 )

• Match includes hash and hash* patterns. (see https://docs.racket-lang.org/reference/match.html#%28form._%28%28lib._racket%2Fmatch..rkt%29._match%29%29 )

• The vector-set/copy function allows creation of a new vector that differs
  at only one index. This change also adds vector-append and vector-copy
  primitives. (see https://docs.racket-lang.org/reference/vectors.html#%28def._%28%28lib._racket%2Fvector..rkt%29._vector-set%2Fcopy%29%29 )

• The pregexp-quote function brings the functionality of regexp-quote
  to pregexps. (see https://docs.racket-lang.org/reference/regexp.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._pregexp-quote%29%29 )

• The C FFI convention-based converter supports PascalCase and camelCase in
  addition to an underscore-based convention. (see https://docs.racket-lang.org/foreign/Defining_Bindings.html#%28form._%28%28lib._ffi%2Funsafe%2Fdefine%2Fconventions..rkt%29._convention~3ahyphen-~3ecamel.Case%29%29 )

• The racket/case library allows case-like forms that use different
  equality comparisons, such as eq? and equal-always?. (see https://docs.racket-lang.org/reference/case.html#%28form._%28%28lib._racket%2Fcase..rkt%29._case%2Fequal%29%29 )

• Scribble rendering to HTML adds linking and information buttons when
  hovering over heading titles.

• The interval-map data structure supports iterator functions in the style
  of gen:ordered-dict. (see https://docs.racket-lang.org/data/Orders_and_Ordered_Dictionaries.html#%28def._%28%28lib._data%2Forder..rkt%29._gen~3aordered-dict%29%29 )

The following people contributed to this release:

Alex Harsányi, Alex Knauth, Alex Muscar, Alexis King, Ben Greenman, Bert
De Ketelaere, Bob Burger, Bogdan Popa, Chris Payne, Fred Fu, J. Ryan
Stinnett, Jamie Taylor, Jared Forsyth, Jarhmander, Jens Axel Søgaard,
Joel Dueck, John Clements, Jordan Johnson, Ken Harris, Laurent Orseau,
Mao Yifu, Marc Nieper-Wißkirchen, Matteo d’Addio, Matthew Flatt,
Matthias Felleisen, Micah Cantor, Mike Sperber, naveen srinivasan, Oscar
Waddell, Philip McGrath, Philippe Meunier, Robby Findler, Rocketnia, Sam
Phillips, Sam Tobin-Hochstadt, Sarthak Shah, Shu-Hung You, Sorawee
Porncharoenwase, Stephen De Gabrielle, Tom Price, ur4t, Wing Hei Chan,
and ZhangHao

---

Racket v8.11.1

---

Racket version 8.11.1 is now available from https://racket-lang.org/

This bug-fix release repairs a problem with building from source when using the "builtpkgs" source distribution.

Feedback Welcome

---

Racket v8.11

---

Racket version 8.11 is now available from

https://racket-lang.org/

As of this release:

• Match clauses can include a #:do option to allow evaluation of code
  and bindings before a following #:when clause. Cf. https://docs.racket-lang.org/reference/match.html#%28form._%28%28lib._racket%2Fmatch..rkt%29._match%29%29

• JSON Serialization supports indentation with an #:indent option to
  write-json. Cf. https://docs.racket-lang.org/json/index.html#%28def._%28%28lib._json%2Fmain..rkt%29._write-json%29%29

• An initiate-sequence function simplifies the creation of sequences.
  Cf. https://docs.racket-lang.org/reference/sequences.html#%28def._%28%28lib._racket%2Fsequence..rkt%29._initiate-sequence%29%29

• The :do-in form allows an inner definition sequence. Cf. https://docs.racket-lang.org/reference/for.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._~3ado-in%29%29

• The redex-define form allows pattern-matching in PLT Redex using a
  define-like syntax. Cf. https://docs.racket-lang.org/redex/reference.html#%28form._%28%28lib._redex%2Freduction-semantics..rkt%29._redex-define%29%29

• Racket and Chez Scheme use Robert L. Smith's "Algorithm 116" for
  division of complex numbers. Cf. https://dl.acm.org/doi/10.1145/368637.368661

• DrRacket has indentation guides that provide visual cues indicating
  how code is indented and grouped, accessible by using
  (<menu-key>-shift-i).

• "Comment-out" menu items can be specific to the #lang used by the
  current file. Cf. https://docs.racket-lang.org/framework/Text.html#%28def._%28%28lib._framework%2Fmain..rkt%29._text3aindent-guides3c253e%29%29

• Unused identifiers have a tooltip indicating that they have no bound
  occurrences.

• Quickscript includes a new form of scripting in the form of "hook"
  functions that can be attached to existing events. Cf. https://docs.racket-lang.org/quickscript/index.html#%28part._.Hooks%29

• Plots include plot-inset and plot-legend-padding parameters to
  control the amount of space left unused around the plot edge and plot
  legend. Cf. https://docs.racket-lang.org/plot/params.html#%28def._%28%28lib._plot%2Fmain..rkt%29._plot-inset%29%29

• There are many other documentation improvements, optimizations, and
  bug fixes!

Thank You

Thank you to the people who contributed to this release:

Alex Harsányi, Ben Greenman, Bogdan Popa, Cameron Moy, Camille
d’Alméras, D. Ben Knoble, Efraim Flashner, Eric S. Raymond, Fred Fu,
Greg Hendershott, Gustavo Massaccesi, Jay McCarthy, jim, Joel Dueck,
John Clements, Jon Eskin, Laurent Orseau, Lucas Sta Maria, mAdkins, Mark
Hedlund, Matteo d’Addio, Matthew Flatt, Matthias Felleisen, Mike
Sperber, Noah Ma, Oscar Waddell, Philip McGrath, Qifan Wang, Robby
Findler, Ross Angle, Ryan Culpepper, Sam Tobin-Hochstadt, shenleban
tongying, Shu-Hung You, Sorawee Porncharoenwase, Stephen De Gabrielle,
Wing Hei Chan, xxyzz, and ZhangHao

Feedback Welcome

Racket v8.10

---

Racket version 8.10 is now available from

https://racket-lang.org/

As of this release:

• syntax/parse no longer always compiles its patterns; this release
  includes an interpreter which is used to reduce code size

• Racket includes primitives [im]mutable-string?, [im]mutable-bytes?,
  [im]mutable-vector?, [im]mutable-box?, and [im]mutable-hash?
  (cf.
  https://docs.racket-lang.org/reference/booleans.html#%28mod-path._racket%2Fmutability%29)

• Redex adds judgment-form->rule-names (cf.
  https://docs.racket-lang.org/redex/reference.html#%28def._%28%28lib._redex%2Freduction-semantics..rkt%29._judgment-form-~3erule-names%29%29)

• Fasl and compiled code allow fxvectors and flvectors

• DrRacket allows #lang-specific customization of the definition
  navigation popdown (cf.
  https://docs.racket-lang.org/tools/drracket_language.html#%28idx._%28gentag._55._%28lib._scribblings%2Ftools%2Ftools..scrbl%29%29%29)

• Racket and DrRacket include Finnish internationalization

• Check Syntax binding arrows are drawn for names bound with
  define-local-member-name

• Many other improvements and bug fixes are included, including to
  the scribble and plot packages

Thank you

Thank you to the people who contributed to this release:

Adrien Ludwig, Alex Harsányi, Alex Knauth, Alexis King, Ben Greenman,
Cameron Moy, D. Ben Knoble, Greg Hendershott, Gustavo Massaccesi,
irreconsolable, Jay McCarthy, Joel Dueck, John Clements, Jordan Johnson,
Kamil Laskowski, Laurent Orseau, Matthew Flatt, Matthias Felleisen, Mike
Sperber, Oscar Waddell, Pavel Panchekha, Philip McGrath, reflektoin,
Robby Findler, Ryan Culpepper, Sam Tobin-Hochstadt, Shu-Hung You, Stefan
Schwarzer, Stephen De Gabrielle, and Yongming Shen

Feedback Welcome

Racket v8.9

Racket version 8.9 is now available from https://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.
  https://docs.racket-lang.org/htdp-langs/beginner-abbr.html?q=signatures#%28part._beginner-abbr-signatures%29)

• 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. https://docs.racket-lang.org/reference/Equality.html#%28mod-path._racket%2Fhash-code%29)

• A language module can have a configure-expand submodule that is
  dynamically required to configure a parameterization before expansion
  of another module. (cf. https://docs.racket-lang.org/reference/running-sa.html#%28part._configure-expand%29)

• stream-cons supports multiple values. (cf. https://docs.racket-lang.org/reference/streams.html#%28form._%28%28lib._racket%2Fstream..rkt%29._stream-cons%29%29)

• 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. https://docs.racket-lang.org/reference/unitcontracts.html#%28form._%28%28lib._racket%2Funit..rkt%29._unit%2Fc%29%29)

• racket/class provides the dynamic-instantiate procedure for
  instantiating a class with a dynamic list of by-name initialization
  arguments. (cf. https://docs.racket-lang.org/reference/objcreation.html#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._dynamic-instantiate%29%29)

• TCP output block buffering implies TCP_NODELAY. (cf. https://docs.racket-lang.org/reference/tcp.html#%28def._%28%28lib._racket%2Ftcp..rkt%29._tcp-connect%29%29)

• 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.

Racket v8.8

---

Racket version 8.8 is now available from

https://racket-lang.org/

As of this release:

• The dependent contract form, ->i, supports a #:param element that
  specifies dependencies for parameter values that are set during the
  dynamic extent of the function call.
  (See: https://docs.racket-lang.org/reference/function-contracts.html#%28form._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._-~3ei%29%29 )

• The copy-file library function supports permission-management
  arguments.
  (See: https://docs.racket-lang.org/reference/Filesystem.html#%28def._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._copy-file%29%29 )

• Pressing <SHIFT>-return in DrRacket's interactions window makes
  it easier to edit and enter expressions without sending them
  to be evaluated.

• The numeric comparison operators (<, >=, etc.) require at least
  two arguments in the "How To Design Programs" teaching languages.

• Redex has improved typesetting when customized renders are used
  in certain multi-line situations.

• We have fixed many bugs, and written lots of documentation.

The following people contributed to this release:

Alex Knauth, Alexander Shopov, Andreas Schwab, Ben Greenman, Bert De
Ketelaere, Bob Burger, Bogdan Popa, Cameron Moy, Chung-chieh Shan,
D. Ben Knoble, Dan Anderson, David Van Horn, Geoffrey Knauth, Gustavo
Massaccesi, Jamie Taylor, Jason Hemann, Jens Axel Søgaard, Jesse Alama,
jestarray, Johann Rudloff, Johannes Maier, John Clements, Jon Zeppieri,
Lazerbeak12345, Lîm Tsú-thuàn, Matthew Flatt, Matthias Felleisen, Mike
Sperber, Niklas Larsson, Noah Ma, Pavel Panchekha, Philip McGrath,
Philippe Meunier, R. Kent Dybvig, reflektoin, Robby Findler, Sam
Tobin-Hochstadt, Shu-Hung You, Sorawee Porncharoenwase, and Stephen De
Gabrielle

Feedback Welcome

Racket v8.7

---

Racket version 8.7 is now available from

https://racket-lang.org/

As of this release:

• Typed Racket offers Shallow and Optional modes for its gradual
  types. These modes lower the cost of interacting with untyped code,
  but provide less protection against buggy interactions.
  (see https://docs.racket-lang.org/ts-reference/behavior-of-types.html )
• Racket uses Unicode 14.0 for character and string operations, and
  includes grapheme operations. DrRacket supports emojis.
  (see https://docs.racket-lang.org/gui/editor-overview.html#%28part._graphemes%29 )
• Racket supports RV64G (RISC-V).
• Programmers can disable definition shadowing using
  (#%declare #:require=define).
  (see https://docs.racket-lang.org/reference/module.html#%28form._%28%28quote._~23~25kernel%29._~23~25declare%29%29 )
• The module dependency graphs available using raco dependencies-graph
  and DrRacket's Module browser are faster and have new package
  filtering support.
  (see https://docs.racket-lang.org/drracket/module-browser.html#%28idx._%28gentag._39._%28lib._scribblings%2Fdrracket%2Fdrracket..scrbl%29%29%29 )
• DrRacket is more responsive when killing programs that produce a lot
  of output.
• Plot 3D allows negative altitude values (e.g., looking at the plot
  from "below".)
  (see https://docs.racket-lang.org/plot/plotting.html#%28def._%28%28lib._plot%2Fmain..rkt%29._plot3d%29%29 )
• The scriblib/bibtex and scriblib/autobib libraries support DOIs.
  (see https://docs.racket-lang.org/scriblib/autobib.html#%28def._%28%28lib._scriblib%2Fautobib..rkt%29._make-bib%29%29 )
• There are many other repairs and improvements!

The following people contributed to this release:

Adit Cahya Ramadhan, Alex Harsányi, Bart van Strien, Ben Greenman, Bob
Burger, Bogdan Popa, Cameron Moy, cheeze2000, D. Ben Knoble, Dan
Anderson, Fred Fu, Geoffrey Knauth, Gustavo Massaccesi, J. Ryan
Stinnett, Jack Firth, Jason Hemann, Jimmy McNutt, John Clements, Lîm
Tsú-thuàn, M. Taimoor Zaeem, Mao Yifu, Matthew Flatt, Matthias
Felleisen, Mike Sperber, Noah Ma, Oliver Flatt, Paulo Matos, Philip
McGrath, Reuben Thomas, Robby Findler, Ryan Culpepper, Sam Phillips, Sam
Tobin-Hochstadt, Samuel Bronson, Shu-Hung You, Sorawee Porncharoenwase,
Sorin Muntean, Stephen Chang, William J. Bowman, and Winston Weinert

Feedback Welcome

Racket v8.6

Racket version 8.6 is now available from

https://racket-lang.org/

As of this release:

• Racket has an "equal-always?" primitive that equates values that will stay
  the same even if mutated. See
  https://docs.racket-lang.org/reference/Equality.html#%28def._%28%28quote._~23~25kernel%29._equal-always~3f%29%29

• This release uses a new build system, Zuo, which is implemented as a
  little language, in accordance with the ideas of Language Oriented
  Programming (LOP). The implementation has a single C file (plus libraries
  implemented in Zuo), so it compiles easily. The zuo/build
  library is modeled on make and Shake for tracking dependencies and
  build steps. See https://docs.racket-lang.org/zuo/index.html and
  https://racket.discourse.group/t/new-build-system-pushed-to-git-repo/873

• Racket supports stencil vectors, which associate a virtual bitmask
  with a vector, enabling certain mask-equipped update operations. See
  https://docs.racket-lang.org/reference/stencil_vectors.html

• Racket supports Arm64 machines running Windows.

• Redex has support for simultaneous substitutions. See
  https://docs.racket-lang.org/redex/reference.html#%28form._%28%28lib._redex%2Freduction-semantics..rkt%29._substitute%29%29

• The Web Server provides control over the maximum number of
  concurrent connections via its "safety limits" construct. See
  https://docs.racket-lang.org/web-server-internal/dispatch-server-unit.html#%28part._safety-limits%29

• The Web Server has improved logging performance and improved
  request parsing performance, reducing tail latencies.

• The Web Server supports logging response status code via
  web-server/dispatchers/dispatch-logresp. See
  https://docs.racket-lang.org/web-server-internal/dispatch-logresp.html

• The db library supports custom types for PostgreSQL connections; see
  pg-custom-type for details. See
  https://docs.racket-lang.org/db/util.html#%28def._%28%28lib._db%2Futil%2Fpostgresql..rkt%29._pg-custom-type%29%29

• The release includes many other repairs and changes!

The following people contributed to this release:

Alex Knauth, Alexander Shopov, Alexis King, Amirouche Amazigh BOUBEKKI,
Andy Keep, Ashish SHUKLA, Bob Burger, Bogdan Popa, Cameron Moy,
Chung-chieh Shan, David K. Storrs, FrankHB, Fred Fu, Gustavo Massaccesi,
helado de brownie, J. Ryan Stinnett, Jack Firth, Jamie Taylor, Jason
Hemann, Jens Axel Søgaard, Jimmy McNutt, Joel Dueck, John Clements, José
Manuel Calderón Trilla, Kevin Tew, Laurent Orseau, Matt Audesse, Matthew
Flatt, Matthias Felleisen, Mike Sperber, naveen srinivasan, Niklas
Larsson, Noah Ma, Oscar Waddell, Pavel Panchekha, Phil Nguyen, Philip
McGrath, Philippe Meunier, rgkirch, Robby Findler, Robert Postill, Ryan
Culpepper, Sam Tobin-Hochstadt, Sergiu Ivanov, Sorawee Porncharoenwase,
Stephen De Gabrielle, Vincent Lee, wackbyte, and Zibing Zhang

Link to package regressions issue for the 8.6 release:
#4366

Racket v8.5

As of this release:

• Racket's new -y flag automatically keeps compiled files up to date,
  reducing subsequent load times.

• Error-message realms allow Racket-hosted languages to adapt and
  rewrite error messages to make sense in a particular context.

• Nonprivileged users can control package installation scope using an
  "other-version" directory in the addon-dir.

• Racket CS runs on platforms where native-code generation is not
  currently supported (e.g., s390x or ppc64). See "README.txt" in the
  source distribution for more information on the --enable-pb flag to
  configure.

• DrRacket's new 'Reopen Closed Tab' file menu item will open previously
  closed tabs.

• Typed Racket has support for the xml library; use typed/xml.

• Rackunit reports source locations for failed test cases in the
  Typed Racket language.

• Plot has violin plots and improved box-and-whisker plots.

• Boxes are supported alongside lists, vectors etc. in place-channel
  messages.

• Those who manually configure Racket CS to use Zlib compression for
  compiled code should be aware of CVE-2018-25032; the next release and
  the current snapshot builds use a newer, safer version of zlib.

• The release includes many other repairs and changes!

The following people contributed to this release:

Alex Harsányi, Alexander Shopov, Alexis King, Andrew Mauer-Oats, Ben
Greenman, Benedek Szilvasy, Bert De Ketelaere, Bogdan Popa, Cameron Moy,
Chung-chieh Shan, Fred Fu, Gustavo Massaccesi, J. Ryan Stinnett, Jamie
Taylor, Joel Dueck, John Clements, Joseph Griego, Khadija Sidhpuri,
Laurent Orseau, Maciej Barć, Matthew Flatt, Matthias Felleisen, Mike
Sperber, Noah Ma, Philip McGrath, Robby Findler, Ryan Culpepper, Sam
Tobin-Hochstadt, Sorawee Porncharoenwase, Stephen De Gabrielle, Tim
Jervis, and Trevor Paley