Release notes from racket

Racket v6.0.1

2014-05-08T20:13:40Z

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.

Racket v6.0

2014-02-26T22:18:28Z

Racket 6.0 has a new package system, including a catalog of
hundreds of already-available packages. Please visit

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.

Racket v5.93

2014-01-31T23:23:45Z

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.

Racket v5.92

2014-01-25T16:56:08Z

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.

Racket v5.3.6

2013-08-10T12:47:15Z

Racket v5.3.6 is a bug-fix release. It eliminates errors from v5.3.5
that people have found over the summer.

Racket v5.3.5

2013-06-18T11:00:31Z

This is a special-purpose release to match the arrival of "Realm of
Racket" in bookstores. Racket v.5.3.5 adds a single `realm'
collection to the v5.3.4 release. The new collection contains the
source code that readers of Realm may wish to use for experiments.

Racket v5.3.4

2013-05-08T16:21:58Z

Extflonums (80-bit floating-point numbers) are supported on some
x86/x86_64 platforms -- including Windows, and including platforms
where Racket is compiled to use SSE instructions for flonum
arithmetic. Thanks to Michael Filonenko.
OS X: DrRacket and all of the other apps are now signed with an
official key.
Tally Maze: a new game based an enumeration of 2d mazes.
The Optimization Coach, a DrRacket plugin, has been moved from the
Racket distribution to the Racket package repository. Install it
with: raco pkg install optimization-coach
Redex: `define-union-language' now merges productions when
languages define the same nonterminals. Thanks to William Bowman.
The srfi/19' library is now compatible with the date structure type exported by racket/base'.

Racket v5.3.3

2013-02-15T20:38:09Z

This is a bug-fix release to address a flaw in DrRacket v5.3.2
concerning interactions between the contour window and the syntax
coloring.

Racket v5.3.2

2013-02-01T03:58:47Z

Core Libraries:

The new `math' library provides functions and data structures for
working with numbers and collections of numbers. Functions include
non-elementary (such as gamma, zeta, Lambert's W), number-theoretic
(factorization, modular arithmetic), linear algebra (arithmetic,
decompositions), and statistical (expected values, order statistics,
binning). Data structures include arbitrary-precision bigfloats,
probability distributions, and multidimensional arrays.
The new file/untar', file/untgz', and `file/unzip' libraries support
unpacking widely used archive formats.
The new `lazy-require' form allows programs to delay the loading and
instantiation of helper modules until they are needed.
The new `data/bit-vector' library provides an implementation of bit
vectors (a mutable sequence of booleans) supporting popcount.
The `racket/generic' library allows the specification of default
method implementations for core datatypes.
The `openssl' library can verify hostnames and use the operating
system's certificate store to verify certificates.

Package System:

A new package system is in beta release. This system will become
Planet's successor. It differs significantly from the latter. For
details, please read the documentation at
http://docs.racket-lang.org/planet2/ and list your packages on the new
index at https://pkg.racket-lang.org/.
The `raco test' command supports testing by collection and package, in
addition to by directory and file, with the "-c" and "-p" options.

Teaching Libraries:

batch-io: the read and write functions work on Unix-style standard
input and output.

DrRacket:

DrRacket's GUI is more responsive.
The automatic parenthesis insertion mode is improved.

Scribble:

Scribble renders Markdown format files via the "--markdown"
command-line flag. Example use case: Generate documentation hosted on
GitHub or BitBucket.
Documentation cross-reference information is stored in an SQLite3
database, which means that SQLite3 is required for building Racket
documentation on Unix/Linux machines (but SQLite3 is included in
Racket distributions for Windows and Mac OS X).

Using a database for cross-reference information significantly reduces
the initial footprint of DrRacket, since DrRacket no longer needs to
load all cross-reference information.

Typed Racket:

Typed Racket programs can require `plot/typed' to draw plots. List-
and vector-accepting functions accept general sequences.
Typed Racket supports Racket's delimited continuation and continuation
mark operators.

Redex:

Added more support for `define-judgment-form', including random
generation for well-formed judgments and visualization of judgments.

Deprecation:

The following have been removed in this release:

the planet' command-line tool; use raco planet' instead.

The following has been deprecated and will be removed in the August 2013
release:

the mzlib/class100' library; use racket/class' instead.

Racket v5.3.1

2012-11-07T19:50:41Z

Racket:

The `case' form dispatches on characters, fixnums, symbols, and
keywords in logarithmic time. (Thanks to Jon Zeppieri.)
The new `racket/format' library provides new and improved
string-formatting functions.
Logging tools include improved filtering support based on the name
of a logger. A new define-logger' form simplifies the use of named loggers. Forms such as log-debug' now support string
formatting.
The for' forms now support #:break' and `#:final' clauses.
The new PLTCOMPILEDROOTS environment variable configures the
search path for compiled bytecode.

DrRacket:

Check Syntax now summarizes the documentation (i.e., the blue
boxes) for the identifier at the insertion point in the top-right
corner of the definitions window.
Check Syntax now runs continuously for programs that declare their
language within the source. This mode has been available for
several of the past releases, but now enabled by default.
DrRacket can spell-check string constants (enable this in the Edit
menu).

Typed Racket:

Typed Racket interprets the Any type as a different contract.
This may signal dynamic errors in some existing mixed
typed/untyped programs. The normal fix is to replace a use of Any
with a more specific types.
NaN is included in all of Typed Racket's floating-point types,
which makes precise floating-point types easier to use.
Typed Racket supports a `cast' operation with support for
higher-order types.
Typed Racket provides the :query-type/args' and :query-type/result' utilities to explore types at the REPL.

Miscellaneous:

The compatibility' collection provides features from Racket relatives, such as defmacro' and mutable lists. These features
are provided to ease porting code to Racket. Avoid them in modern
Racket code.
Screenshots of the widgets provided by the Racket GUI library are
included in the documentation. (Thanks to Diogo F. S. Ramos.)
FrTime was ported to racket lang. (Thanks to Patrick Mahoney.)

Deprecation:

The following has been deprecated and will be removed in the January
2013 release:

the planet' command-line tool; use raco planet' instead.

The following has been deprecated and will be removed in the August
2013 release:

the mzlib/class100' library; use racket/class' instead.