Racket v6.2 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`.