Racket v5.1.1
posted by Eli Barzilay
Racket version 5.1.1 is now available from http://racket-lang.org/
-
The new
racket/stream
library providesstream-first
,stream-rest
, a lazystream-cons
, and so on. Streams are a subtype of sequences, so they work infor
forms. Some sequence generators, such asin-range
, now produce streams. Aracket/sequence
library replaces the oldracket/stream
library. -
The new
racket/syntax
library contains facilities useful for writing macros. The newsyntax/srcloc
andsyntax/location
libraries provide support for manipulating source locations. -
The
racket/gui
library now supports multi-column list boxes and scrolling panels. -
The new
ffi/file
library is useful for writing foreign library bindings that cooperate with Racket’s security guard mechanism. -
Generators from the
racket/generator
library can now have formal arguments that are used when the generator is fired up. -
Single-precision floating-point support is now enabled by default. Single-precision floats print differently from their default double-precision counterparts, new primitives convert between the two precisions, and new reader syntax supports single-precision literals.
-
JIT improvements include a small change to aid x86 branch prediction on function-call returns, which can speed up some programs significantly.
-
Typed Racket:
-
The numeric tower has been entirely overhauled. TR programs can now use more precise types than before, and check more numeric properties, such as sign or range properties.
-
Fixnum optimizations have been improved and should apply more broadly.
-
The performance of the typechecker has been improved. In particular, dispatch on large union types should typecheck much faster than before.
-
The Stepper can now step through Lazy Racket programs.
-
The
racket/future
library includesfsemaphore
values, thefuture
primitive no longer freezes futures (so a future can spawn new futures), andfuture
log messages are more informative. -
PLaneT development links are now version-specific.
-
The
2htdp/image
library now includesoverlay/align
,underlay/align
,overlay/align/offset
andunderlay/align/offset
. -
The network protocol for universes in
2htdp/universe
has changed, so that v5.1.1 is incompatible with earlier versions. -
The “DrScheme” application (which simply ran DrRacket in the last few releases) has been removed. The “MrEd” GUI executables for Windows and Mac OS X have also been removed, although the “mred” console executable remains for Unix and Mac OS X to support old scripts.
Are there plans to include a windows x86_64 version at some point? Thanks!
— deforce, 16 July 2011
Yes, we now have a Windows x86_64 build. You can try a nightly build (http://pre.racket-lang.org/installers) or wait for the next version which should be out very soon.
— Eli Barzilay, 17 July 2011