[Racket announcement] Racket v6.0
Racket version 6.0 is now available from http://racket-lang.org/ Racket 6.0 has a new package system, including a catalog of hundreds of already-available packages. Please visit http://pkgs.racket-lang.org/ for an overview of the packages. Racket versions 5.3.4 through 5.3.6 included "beta" versions of the package system. Racket version 6.0 incorporates many improvements suggested by preliminary experiences in those versions: * A package is treated as a single collection by default, so it is even easier to use a GitHub repository as a package. Get started quickly: http://docs.racket-lang.org/pkg/getting-started.html * DrRacket includes a new package manager GUI, available via the File|Package Manager ... menu item. The GUI is also available as a stand-alone program via the "gui-pkg-manager" package. * The main Racket distribution has been separated into about 200 packages. The Racket installer combines the core system with bundled versions of these packages. Alternatively, you may now install a Minimal Racket distribution --- which is about 1/10 the size of the main distribution --- and add only those packages that you need. * Package installation supports pre-built packages that include compiled byte code and rendered documentation, meaning packages can be installed quickly when built versions are available. All packages in the main distribution are available in pre-built form. The recent 5.92 and 5.93 releases served as release candidates for 6.0, and 6.0 includes a few additional repairs related to the package system. Further improvements to the package system are in the works, notably including package documentation on the package-catalog web site. COMPATIBILITY NOTE: PLaneT, the previous Racket package system, will remain in place for the foreseeable future, but we expect all package work to shift to the new system. Beyond the package system, this release brings a number of other changes: * Racket's HTML documentation has a new and improved look, thanks to Matthew Butterick. * The documentation includes a style guide, "How to Program Racket" http://docs.racket-lang.org/style/ * Racket's JIT compiler supports the ARM architecture. * Racket supports the Mac's Retina display mode. * The performance of the Typed Racket compiler improved by 50% on some typed programs; e.g., see http://bit.ly/1d0Ye4z * The profiler provides a new mode that uses the errortrace library to produce fine-grained profiles. * A new contract profiler reports how much time programs spend checking contracts, and which contracts are most expensive. * The math/flonum library exports fast 105-bit precision operations. * Check Syntax handles generated identifiers, especially those introduced by struct (e.g. field selectors) and Redex (e.g., e_1, e_2) * 2htdp/batch-io includes functions for dealing with html/xml in files and web sites as X-expressions plus conveniences for web-based graph traversals. * The `gen:set' generic interface extends set operations to work on user-defined types that implement set methods, as well as on other set-like built-in types, such as lists. * Picts support conversion to SVG format. * Under unix, Racket provides desktop entries (.desktop files) for its graphical executables. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.0.1
Racket version 6.0.1 is now available from http://racket-lang.org/ * A new `racket/undefined` library exports `undefined` as the value currently produced by (letrec ([x x]) x) This library anticipates a future where that expression will raise an exception. The `racket/undefined` library will continue to offer the `undefined` value as a bridge between versions and as a last resort. * The drawing and GUI libraries provide improved support for high-resolution bitmaps and their use on Retina displays. For example, `read-bitmap` includes a `#:try-@2x?` option to trigger substitutions through the usual "@2x" naming convention. * Check Syntax cooperates with Typed Racket to show arrows and other Check Syntax highlighting even when there is a type error. * Functions provided via contract-out that have first-order contracts perform better. * The contract boundary between typed/untyped modules is much less expensive. Typed Racket now avoids generating contracts for places where contracts failures cannot happen. * Occurrence typing now works better with when/unless. Example: (let ((x (read))) (unless (number? x) (error 'bad-input)) (add1 x)) * Types in Typed Racket are now pretty-printed. * Function types can now be written in prefix style, which is now preferred and is used for printing. Infix function types are still accepted for backwards compatibility. * A new `->*' type constructor is used for writing types for functions with optional and keyword arguments. The notation is similar to the matching contract combinator. * Typed Racket forms do not have a `:' suffix by default now. For example, the `struct' form replaces `struct:'. The suffixed versions are all provided for backwards compatibility. * Typed Racket now has preliminary support for classes and objects. However, it is still experimental and the APIs are subject to change. * Type aliases in Typed Racket now support recursion and mutual recursion. For example, `(define-type (MyList X) (U Null (Pair X (MyList X' is now a valid type alias. * Plot correctly renders intersecting 3D graphs and non-grid-aligned 3D rectangles. * Elements in plots output in PDF/PS format have the same relative scale as in other formats. In particular, it is not necessary to adjust `plot-font-size` to make PDF plots look the same as PNG. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.1
PLT Design Inc. announces the release of Racket version 6.1 at http://racket-lang.org/ The MAJOR INNOVATION concerns local recursive variable definitions. Instead of initializing variables with an `undefined' value, Racket raises an exception when such a variable is used before its definition. (Thanks to Claire Alvis for adapting Dybvig's "Fixing Letrec" work.) Since programs are rarely intended to produce #, raising an exception provides early and improved feedback. Module-level variables have always triggered such an exception when used too early, and this change finally gives local bindings --- including class fields --- the same meaning. This change is backwards-incompatible with prior releases of Racket. Aside from exposing a few bugs, the change will mainly affect programs that include (define undefined (letrec ([x x]) x)) to obtain the # value. In its stead, Racket provides the same value via the `racket/undefined' library (which was introduced in the previous release). Programmers are encouraged to use it in place of the pattern above to obtain the "undefined" value. The release also includes the following SMALL CHANGES: * PLUMBERS generalize the flush-on-exit capability of primitive output ports to enable arbitrary flushing actions and to give programmers control over the timing of flushes (i.e., a composable `atexit'). New functions include `current-plumber', `plumber-add-flush!', and `plumber-flush-all'. * CONTRACTS: the contract system's random testing facility has been strengthened so that it can easily find simple mistakes in contracted data structure implementations (e.g. an accidental reverse of a conditional in a heap invariant check). * REDEX: the semantics of mis-match patterns (variables followed by _!_) inside ellipses has changed in a backwards-incompatible way. This change simplifies the patterns' semantics and increases the usefulness of these patterns. * TEACHING LANGUAGES: `check-random' is an addition to the preferred unit testing framework in the teaching languages. It enables the testing of students' functions that use random-number generation. (Thanks to David Van Horn (UMaryland) for proposing this idea.) * Upgraded and normalized versions of GRAPHICS LIBRARIES and dependencies (Pango, Cairo, GLib, etc.) that are bundled with Racket on Windows and Mac OS X. For example, FreeType support is consistently enabled. * TYPED RACKET: its standard library includes contracted exports from the Racket standard library, such as the formatting combinators of `racket/format'. It also supports Racket's asynchronous channels; see the `typed/racket/async-channel' library. * SSL: The openssl library supports forward secrecy via DHE and ECDHE cipher suites (thanks to Edward Lee) and Server Name Indication (thanks to Jay Kominek). * The `mzlib/class100' library has been REMOVED. Use `racket/class' instead. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.1.1
Racket version 6.1.1 is now available from http://racket-lang.org/ * The MAC OS X YOSEMITE compatibility problems are fixed. We bundled a patched Pango text-drawing library with Racket. * The WINDOWS [32-bit] releases fixes the window-update crashes. We bundled a patched Cairo drawing library with Racket. * TYPED RACKET closes two safety holes in the exception system. The revised type system restricts `raise' to send only instances of the `exn' structure type and flat data to handlers. It also checks exception handlers properly. NOTE: Previously well-typed programs may fail to typecheck. * TYPED RACKET'S typed regions support casts and predicates. * 2HTDP/IMAGE'S notion of equality ignores an image's baseline. * The PACKAGE MANAGER supports a binary library installation mode, which allows users to install packages without source or documentation. Use the `--binary-lib' option with `raco pkg install'. * The new DRRACKET-TOOL-LIB package factors out parts of DrRacket's IDE so that they can be reused with other editors, such as Emacs. * The COMPILER'S use-before-defined analysis has been repaired for certain forms of nested `letrec', some `let' forms, and some uses of `set!' or `with-continuation-mark'. * The COMPILER performs additional bytecode optimizations. Thanks to Gustavo Massaccesi. * The CML library comes with a new `replace-evt' event constructor. Thanks to Jan Dvořák. * REDEX'S benchmark suite comes with a description of the benchmark programs. * REDEX'S metafunctions can be typeset using the "large left brace" notation for conditionals. * The CONTRACT library comes with an improved `contract-stronger?'. Its error messages note that the contract itself might be wrong. * The GUI library is DPI-aware on Windows. * The OPENSSL library supports Server Name Indication for servers. Thanks to Jay Kominek. * The SYNTAX/PARSE library allows the definition of new pattern forms via pattern expanders, similar to match expanders. Thanks to Alex Knauth. * OpenGL on Linux no longer depends on libgtkgl, and core profiles are supported (see `set-legacy?'). * The TEACHING LANGUAGES' unit test framework supports `check-satisfied', a construct for checking whether a result satisfies a predicate, e.g.: (check-satisfied (sort l) sorted?) Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.2
Racket version 6.2 is now available from http://racket-lang.org/ With this release we are taking a major step forward to get our user community even more involved than in the past. Over the past six months, we have re-organized the Racket code base into a small core code repo and many other package repos, all found on GitHub. If you have time and if you wish to get involved, please take a look at the GitHub repos and find your favorite places to learn, fix, and enhance our world. The core repo is at https://github.com/plt/racket, and the package repos are listed at https://github.com/racket/. core repo * The package manager supports a direct references to Git repositories via "git://[...]", "http://[...].git";, and "https://[...].git"; URLs. (Previously, only references to GitHub were supported.) * A `--clone` option for `raco pkg install` or `raco pkg update` facilitates Git-based package development. If a package X has a Git repository source, installing and updating the package pulls from the repository in a read-only mode. Using `raco pkg update --clone X` switches the local installation to a repository checkout that is suitable for modifying the package implementation, issuing pull requests, pushing changes, and so on. Using `raco pkg update --lookup X` switches the package back to the default installation mode. drracket * Its on-line check syntax works with graphical content. * Increased availability of DrRacket's blueboxes, including method and constructor information. * The "Open Require Path" menu item supports ".." in relative pathnames. data * Added data/enumerate, a library that supports efficient enumeration of data structures redex * Its redex-check facility uses data (in addition to random) enumeration to try to find counter-examples. * Its generate-term function accepts additional arguments to return the "i"-th member of a pattern using data/enumerate (meaning it efficiently supports very large values of "i"). * The examples collection includes Launchbury's 1993 big-step lazy semantics. htdp * 2htdp/image's polygon may be built out of bezier curves instead of just straight lines (see the docs for "pulled-point"). * 2htdp/abstraction is a teachpack for instructors and students who wish to use for/* loops, match, define-type and type-cases in ISL and ISL+. * 2htdp/universe programs can be exported using DrRacket's executable creation mechanism and they behave properly when run independently. typed-racket * Typed Racket in DrRacket displays tooltips that show the types of expressions. Tooltips are also displayed for type errors. * Typed Racket loads generated contracts only when needed. This reduces memory use and startup time for Typed Racket programs. * Typed Racket has improved support for prefab structures, future semaphores, and async channels. * Typed Racket understands when two different variables refer to the same thing, and updates types accordingly. This particularly improves the type checking of macros such as `match`. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.2.1
Racket version 6.2.1 is now available from http://racket-lang.org/ Version 6.2.1 patches the recent v6.2 release in three small ways: * For the How to Design Programs teaching languages, DrRacket offers an option to use the old style for printing the constants `true`, `false`, and `empty` instead of `#true`, `#false`, and `'()`. * The teaching languages come with some additional functions to match the August 2015 stable release of HtDP 2nd edition. * A repair to the compiler avoids an infinite loop at compile time for certain expressions that should loop forever at run time. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.4
Racket version 6.4 is now available from http://racket-lang.org/ - We fixed a security vulnerability in the web server. The existing web server is vulnerable to a navigation attack if it is also enabled to serve files statically; that is, any file readable by the web server is accessible remotely. For more information see http://blog.racket-lang.org/2016/02/racket-web-server-security-vulnerability.html - DrRacket's scrolling is faster. - Incremental garbage-collection mode can eliminate long pauses in a program. For example, incremental mode is useful for avoiding pauses in games and animations. Programs must specifically request incremental mode with `(collect-garbage 'incremental)`, but libraries such as `2htdp/universe` include the request as part of the library's implementation. - The default package catalog is an HTTPS address instead of HTTP, and package operations properly validate server certificates when using HTTPS. - Documentation may define their own categories for the manual top- level page by using strings, rather than only symbols that name pre-defined categories. - The Racket cheat sheet is included in the main distribution. - DrRacket is available in Bulgarian, thanks to Alexander Shopov. - The contract Typed Racket generates for the `Any` type is more permissive, allowing more typed/untyped programs to work without contract errors. - Redex supports binding specifications; describe which variables bind in which expressions and your metafunctions and reduction relations automatically become scope-sensitive. Thanks to Paul Stansifer for this improvement. - All `pict` functions accept `pict-convertible`s. This allows for transparent interoperability between `pict` and libraries like `2htdp/image`. - The `raco profile` and `raco contract-profile` commands provide easy access to profiling tools, without requiring program modifications. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
[Racket announcement] Racket v6.5
Racket version 6.5 is now available from http://racket-lang.org/ - Typed Racket and the `racket/contract` library generate code with lower overhead, speeding up typed/untyped interaction in a number of gradual typing programs we studied. - Macros written using `syntax-parse` automatically emit more accurate error messages. - The contract profiler captures costs from more contract combinators, including all those in the main distribution. - Hash table and set iteration, via both existing and new non-generic sequences, is more performant, up to twice as fast on microbenchmarks. - The Racket optimizer detects many more optimization opportunities, including when variables always hold numbers. - The `db` library supports single-result CALL statements in MySQL. - The `net/dns` library supports SRV records. - The `racket/unix-socket` library supports listen and accept operations. The following people contributed to this release: Adrien Tateno, Alex Knauth, Alexander Shopov, Alexis King, Andrew Kent, Asumu Takikawa, Ben Greenman, Chen Xiao, Chris Jester-Young, Daniel Feltey, Eric Dobson, Georges Dupéron, Gustavo Massaccesi, Ian Harris, Jay McCarthy, Jens Axel Søgaard, John Clements, Leandro Facchinetti, Lehi Toskin, Leif Andersen, Łukasz Dąbek, Marc Kaufmann, Matthew Flatt, Matthias Felleisen, Michael McConville, Mike Sperber, Paul Stansifer, Philippe Meunier, Robby Findler, Rodrigo Setti, Ryan Culpepper, Sam Caldwell, Sam Tobin-Hochstadt, Sorawee Porncharoenwase, Spencer Florence, Stephen Chang, Tony Garnock-Jones, Vincent St-Amour, WarGrey Gyoudmon Ju, and William J. Bowman. Feedback Welcome Racket Announcements list: http://lists.racket-lang.org/announce
