Lambda the Ultimate

Higher-Order Perl is about functional programming techniques in Perl. It's about how to write functions that can modify and manufacture other functions.

Why would you want to do that? Because that way your code is more flexible and more reusable. Instead of writing ten similar functions, you write a general pattern or framework that can generate the functions you want; then you generate just the functions you need according to the pattern. The program doesn't need to know in advance which functions are necessary; it can generate them as needed. Instead of writing the complete program yourself, you get the computer to write it for you.

The book was published on the 8th of March, and the text will likely appear soon on the web site and will remain freely available.

Could we have a way to change the comment viewing options (temporarily) just for one thread (a la Slashdot)?

Another request would be a direct to a post in the thread view. Sometimes I'm reading a thread and want to bookmark a specially insighful post, but I can't just open the post in another tab/window and bookmark it, I have to change the view to collapsed, find the post again, click on it and then bookmark it. It's a habit I acquired while reading the old LtU.

Metaphor is a strongly-typed, multi-stage, object-oriented programming language. Metaphor is based on a subset of C# and is extended with multi-stage programming constructs in the style of MetaML or MetaOCaml. Metaphor is implemented as a compiler on the .NET CLR.

Metaphor features a static type system for object-oriented reflection operations (i.e. run-time type analysis). This allows the reflection system to be safely incorporated into the language’s staging constructs and thus allows the generation of code based on the structure of types.

Ωmega is a new programming language by Tim Sheard which is descended from Haskell and adds new facilities for defining static type constraints, such as allowing "users to write functions at the level of types, and then use those functions in the type of functions at value level". It also has "equality qualified types". See also Programming with Static Invariants in Omega and the manual for more information. Mentioned previously (in passing) on LtU.

MetaKlaim - a Type Safe Multi-stage Language for Global Computing

This paper describes the design and the semantics of MetaKlaim, an higher order distributed process calculus equipped with staging mechanisms. MetaKlaim integrates MetaML (an extension of SML for multi-stage programming) and Klaim (a Kernel Language for Agents Interaction and Mobility), to permit interleaving of meta-programming activities (like assembly and linking of code fragments), dynamic checking of security policies at administrative boundaries and “traditional” computational activities on a wide area network (like remote communication and code mobility). MetaKlaim exploits a powerful type system (including polymorphic types ´a la system F) to deal with highly parameterized mobile components and to dynamically enforce security policies: types are metadata which are extracted from code at run-time and are used to express trustiness guarantees. The dynamic type checking ensures that the trustiness guarantees of wide are network applications are maintained whenever computations interoperate with potentially untrusted components.