From: Eli Barzilay <email@example.com> To: firstname.lastname@example.org Subject: [PLT announcement] PLT Scheme v4.2.3 Date: Tue, 01 Dec 2009 06:03:22 -0500 PLT Scheme version 4.2.3 is now available from http://plt-scheme.org/ * The unit test framework for the teaching languages provides `check-member-of’ and `check-range’ for checking "random functions", i.e., "functions" that may produce several different results for one and the same argument. * Added a new image library, `2htdp/image’. Significant changes from `htdp/image’: - copying and pasting does not introduce jaggies - `equal?’ comparisons are more efficient - added rotation & scaling - got rid of pinholes (new overlay, beside, above functions based on bounding boxes) * The `scheme/vector’ library provides common vector operations (also reprovided by `scheme’). * The `scheme/promise’ library provides several new kinds of promises with alternatives execution strategies. * New port-reading utilities: `in-port’, `port->list’, `file->list’. * A new require-macro, `path-up’, for requiring a file that is higher in the directory tree. [Note that mirror sites can take a while to catch up with the new downloads.] Feedback Welcome, -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://barzilay.org/ Maze is Life!