Racket full changelog

Racket supports parallel threads.
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!

As of this release:
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

Sort and highlight documentation-search results by core documentation and main-distribution packages
Add "language family" to documents, support filtering searches by language family, and highlight results that are not the main family
Add `'ios` as a compilation target distinct from `'macos`
Use `AI_V4MAPPED` and `AI_ADDRCONFIG` for hostname resolution via`getaddrinfo which improves IPv4 vs. IPv6 on some platforms
raco pkg: Add `uninstall` command prefer it to `remove`
raco pkg: Improve `--clone` transition for packages that are included in a distribution, and improve `--unclone` propagation to implied
ffi/unsafe: Add `'zeroed-atomic[-interior]` allocation mode
compiler/demod: Repair for Windows paths and some syntax scopes

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 4.16 Treelists and RRB vector: a practical general purpose immutable sequence, ICFP 2015)
The hash-filter-keys and hash-filter-values functions allow users to filter hashes using a predicate on either keys or values. (see 4.15 Hash Tables: hash-filter-keys, hash-filter-values)
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 4.12 Vectors: vector-extend)
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.