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v6.18fc2f555 · ·
Racket v6.1 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 #<undefined>, 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 #<undefined> 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.
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v6.0.134c24ef1 · ·
Racket v6.0.1 * 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. -
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v6.0b9bea2d7 · ·
Racket v6.0 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. -
v5.93b090e3fd · ·
Racket v5.93 Version 5.93 repairs a few problems with the recent v5.92 release (in preparation for a v6.0 release): * fixed a low-level concurrency problem with the GUI library for Mac OS X, which especially affected 32-bit builds; * fixed GRacket-based launchers (such as `drracket`) in a Unix-style installation; * expanded the list of recognized OpenSSL library versions; * fixed small CSS problems and inconsistencies (relative to v5.3.6) in the new Scribble style as used by the Racket documentation; and * added the version number back to the "racket" directory within the source distribution bundle.
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v5.9287548795 · ·
Racket v5.92 Racket 5.92 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. Recent releases included the "beta" versions of the package system. Racket version 5.92 incorporates many improvements suggested by these preliminary experiences: * 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. Further improvements 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. -
v5.3.6ded0c4a8 · ·
Racket v5.3.6 Racket v5.3.6 is a bug-fix release. It eliminates errors from v5.3.5 that people have found over the summer.