au:chlipala Ur introduces richer type system features into FP. Ur is functional, pure, statically-typed, and strict. Ur supports metaprogramming based on row types. Ur/Web is standard library and associated rules for parsing and optimization. Ur/Web supports construction of dynamic web applications backed by SQL databases. The signature of the standard library is such that well-typed Ur/Web programs "don't go wrong" in a very broad sense. They also may not: * Suffer from any kinds of code-injection attacks * Return invalid HTML * Contain dead intra-application links * Have mismatches between HTML forms and the fields expected by their handlers It is also possible to use metaprogramming to build significant application pieces by analysis of type structure - demo includes an ML-style functor for building an admin interface for an arbitrary SQL table. The Ur/Web compiler also produces very efficient object code that does not use gc
Ur/Web is a DSL for programming web applications backed by SQL db. It is statically-typed and purely functional. Ur is the base language, and the web-specific features of Ur/Web (mostly) come only in the form of special rules for parsing and optimization. The Ur core looks a lot like Standard ML, with a few Haskell-isms added, and kinder, gentler versions added of many features from dependently-typed languages like the logic behind Coq. The type system is much more expressive than in ML and Haskell, such that well-typed web applications cannot "go wrong," not just in handling single HTTP requests, but across their entire lifetimes of interacting with HTTP clients. Beyond that, Ur is unusual is using ideas from dependent typing to enable very effective metaprogramming, or programming with explicit analysis of type structure. Many common web application components can be built by Ur/Web functions that operate on types
Implementing web applications in an object-oriented language such as Java using state-of-the-art frameworks produces robust software, but involves a lot of boilerplate code. (DSLs) replace boilerplate code by high-level models, from which code can be generated. This tutorial shows how to find domain-specific abstractions based on patterns in existing (reference) programs and build domain-specific languages to capture these abstraction using several DSLs for DSL engineering: SDF for syntax definition and Stratego/XT for code generation. The approach is illustrated using the design and implementation of WebDSL, a domain-specific language for web applications, which provides abstractions for data models, page definitions, access control, workflow, and styling. * WebDSL: A Case Study in Domain-Specific Language Engineering * Code Generation by Model Transformation * Domain-Specific Language Engineering. A Case Study in Agile DSL Development