# Racket v8.16 draft release notes **URL:** \ **Category:** Internals\ **Tags:** release-management, release\ **Created:** [January 27, 2025, 5:09am UTC](https://racket.discourse.group/t/racket-v8-16-draft-release-notes/3518 "2025-01-27T05:09:28Z")\ **Posts on this page:** 1\ **Showing post:** 12
**Author:** ![jbclements](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/jbclements/32/11_2.png) [@jbclements](https://racket.discourse.group/u/jbclements)\ **Post date:** [March 2, 2025, 6:34pm UTC](https://racket.discourse.group/t/racket-v8-16-draft-release-notes/3518/12 "2025-03-02T18:34:15Z")
> [@jbclements](#): > > flbit Okay, here's what I've got now. I just spent _way_ too long on an at-exp format that generates both markdown and text-file-style (no markdown links, lines broken at 80 chars). I'm going to paste the markdown one, let's see how it looks. @spdegabrielle , I diffed against your markdown, and I think the only changes are minor and deliberate. Let me know if you see problems! ## As of this release: - Racket has expanded support for immutable and mutable treelists: - A variety of new treelist utility functions are available: [`treelist-filter`](https://pre-release.racket-lang.org/doc/reference/treelist.html#%28def._%28%28lib._racket%2Ftreelist..rkt%29._treelist-filter%29%29), [`treelist-flatten`](https://pre-release.racket-lang.org/doc/reference/treelist.html#%28def._%28%28lib._racket%2Ftreelist..rkt%29._treelist-flatten%29%29), et cetera. - The [`mutable-treelist-prepend!`](https://pre-release.racket-lang.org/doc/reference/treelist.html#%28def._%28%28lib._racket%2Fmutable-treelist..rkt%29._mutable-treelist-prepend%21%29%29) function allows prepending to mutable treelists. - [Mutable treelists](https://pre-release.racket-lang.org/doc/reference/treelist.html#%28part._.Mutable_.Treelists%29) are [serializable](https://pre-release.racket-lang.org/doc/reference/serialization.html). - The [`serialize-structs`](https://pre-release.racket-lang.org/doc/reference/serialization.html#%28mod-path._racket%2Fserialize-structs%29) module allows the minimization of dependencies by providing only a handful of core forms. - The [`flbit-field`](https://pre-release.racket-lang.org/doc/reference/flonums.html#%28def._%28%28lib._racket%2Fflonum..rkt%29._flbit-field%29%29) function allows access to the binary representation of IEEE floating-point numbers. - The top-left search box in the [documentation](https://pre-release.racket-lang.org/doc/index.html) works once more. - The [XML reader](https://pre-release.racket-lang.org/doc/xml/index.html#%28part._.Reading_and_.Writing_.X.M.L%29) 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](https://pre-release.racket-lang.org/doc/reference/regexp.html#(part._regexp-syntax)), following Perl and PCRE. - The [`read-json*`](https://pre-release.racket-lang.org/doc/json/index.html#%28def._%28%28submod._%28lib._json%2Fmain..rkt%29._for-extension%29._read-json%2A%29%29) and [`write-json*`](https://pre-release.racket-lang.org/doc/json/index.html#%28def._%28%28submod._%28lib._json%2Fmain..rkt%29._for-extension%29._write-json%2A%29%29) 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`](https://pre-release.racket-lang.org/doc/reference/port-lib.html#%28def._%28%28lib._racket%2Fport..rkt%29._open-input-nowhere%29%29) function creates an empty input port. - The [`pipe-port?`](https://pre-release.racket-lang.org/doc/reference/pipeports.html#%28def._%28%28quote._~23~25kernel%29._pipe-port~3f%29%29) function makes it possible to determine whether a port is created by [`make-pipe`](https://pre-release.racket-lang.org/doc/reference/pipeports.html#%28def._%28%28quote._~23~25kernel%29._make-pipe%29%29). - The [`port-file-stat`](https://pre-release.racket-lang.org/doc/reference/file-ports.html#%28def._%28%28quote._~23~25kernel%29._port-file-stat%29%29) function allows gathering information about the file that is the source or target of a file-stream port. - A [revised representation](https://racket.discourse.group/t/fixnum-slow-despite-docs/3409/6) of pointers improves the performance of foreign function calls. As a result, [`ptr-ref`](https://pre-release.racket-lang.org/doc/foreign/foreign_pointer-funcs.html#%28def._%28%28quote._~23~25foreign%29._ptr-ref%29%29) and [`ptr-set!`](https://pre-release.racket-lang.org/doc/foreign/foreign_pointer-funcs.html#%28def._%28%28quote._~23~25foreign%29._ptr-set%21%29%29) are substantially faster. - In anticipation of the fifteenth [RacketCon](https://con.racket-lang.org), the [`fifteenth`](https://pre-release.racket-lang.org/doc/reference/pairs.html#%28def._%28%28lib._racket%2Flist..rkt%29._fifteenth%29%29) function returns the fifteenth element of a list. - Racket has an improved multi-line convention for error messages. - The [`db` library](https://pre-release.racket-lang.org/doc/db/index.html) allows [`prepare`](https://pre-release.racket-lang.org/doc/db/query-api.html#%28def._%28%28lib._db%2Fbase..rkt%29._prepare%29%29) on virtual statements. - The [`student-t` distribution](https://pre-release.racket-lang.org/doc/math/Real_Distribution_Families.html#%28part._.Student-t_.Distributions%29) is part of the [`math/distributions` library](https://pre-release.racket-lang.org/doc/math/dist.html). - [Expeditor](https://pre-release.racket-lang.org/doc/expeditor/index.html) supports customizing the prompt, using the [`#:prompt` keyword argument to `call-with-expeditor`](https://pre-release.racket-lang.org/doc/expeditor/Expeditor_API.html#%28def._%28%28lib._expeditor%2Fmain..rkt%29._call-with-expeditor%29%29). - There is a [guide to adding internationalization for a new (human) language.](https://racket.discourse.group/t/advent-2024-day-translate-drracket-interface-in-your-language/3407) - Optimizations to racket/profile improve asymptotic speed for very large call graphs. - The `#lang htdp/asl` language incorporates [Graphical Debugger](https://docs.racket-lang.org/drracket/debugger.html#%28part._.Debugger_.Buttons%29) support. - There is lots of new documentation, and many defects repaired! --- _[View the full topic](https://racket.discourse.group/t/racket-v8-16-draft-release-notes/3518)._