Category: Link

HtDP on National Radio

HtDP was mentioned on NPR!
Thanks to David for transcribing:

Thomas, Manhattan Beach, CA – Starting a tech company
Thomas is 10 years old and he wants to start a software company with his friends! He programs in C++, Java, and Python?! Wow. Leo says he wants Thomas to learn these programs right, not just noodling with them and learning bad habits. So Leo says that Alice is a good place to start, but Leo suggests HTDP.ORG. It’s a programming book written by software professors all over the country and teaches “SCHEME,” which is a “flavor” of a programming language called LISP. Download DrScheme. This will teach you to plan, design, and organize your software ideas.

(via PLT)

Semantics Engineering with PLT Redex

Semantics Engineering with PLT Redex:

This text is the first comprehensive presentation of reduction semantics in one volume; it also introduces the first reliable and easy-to-use tool set for such forms of semantics. Software engineers have long known that automatic tool support is critical for rapid prototyping and modeling, and this book is addressed to the working semantics engineer (graduate student or professional language designer). The book comes with a prototyping tool suite to develop, explore, test, debug, and publish semantic models of programming languages. With PLT Redex, semanticists can formulate models as grammars and reduction models on their computers with the ease of paper and pencil.
The text first presents a framework for the formulation of language models, focusing on equational calculi and abstract machines, then introduces PLT Redex, a suite of software tools for expressing these models as PLT Redex models. Finally, experts describe a range of models formulated in Redex.
PLT Redex comes with the PLT Scheme implementation, available free at http://www.plt-scheme.org/. Readers can download the software and experiment with Redex as they work their way through the book.

For me this is a long, long, long goal :).

How to Test Functions that are not Exported from a Module

Paulos asked here how to unit test module functions that are not exported. Eli explained two solutions here:

; One way to do this is with `module->namespace' to get the
; namespace of the module (I think that this is how `require/expose'
; works).  Another way which is very convenient for testing is to use
; the sandbox:
 (require scheme/sandbox)
 (define e (make-module-evaluator (string->path "some-file")))
;  and at this point you have `e' bound to an evaluator that works
;  inside of your module, similarly to the repl in drscheme.

Coyotos and Genode OS

Coyotos and Genode are two operating systems about which I had never heard that were mentioned in an Ikarus Users mailing list thread that doesn’t seem to have been mirrored online.
Coyotos:

Coyotos is a secure, microkernel-based operating system that builds on the ideas and experiences of the EROS project.

Genode:

We understand the complexity of code and policy as the most fundamental security problem shared by modern general-purpose operating systems. Because of high functional demands and dynamic workloads, however, this complexity cannot be avoided. But it can be organized. Genode is a novel OS architecture that is able to master complexity by applying a strict organizational structure to all software components including device drivers, system services, and applications. The Genode OS framework is the effort to advance the Genode OS architecture as a community-driven open-source project.