Representations do not necessarily describe the resource, or portray a likeness of the resource, or represent the resource in other senses of the word "represent". Representations of a resource may be sent or received using interaction protocols. These protocols in turn determine the form in which representations are conveyed on the Web. Just as it is important to reuse existing URI schemes whenever possible, there are significant benefits to using media typed octet streams for representations even in the unusual case where a new URI scheme and associated protocol is to be defined.
It is a purely functional languagewhich means that functions generally have no side effects. A distinct construct exists to represent side effects, orthogonal to the type of functions. A pure function can return a side effect that is subsequently executed, modeling the impure functions of other languages.
Haskell has a strongstatic type system based on Hindley—Milner type inference. Its principal innovation in this area is type classes, originally conceived as a principled way to add overloading to the language,  but since finding many more uses.
Monads are a general framework that can model different kinds of computation, including error handling, nondeterminismparsing and software transactional memory.
Monads are defined as ordinary datatypes, but Haskell provides some syntactic sugar for their use. Haskell has an open, published specification,  and multiple implementations exist. Its main implementation, the Glasgow Haskell Compiler GHCis both an interpreter and native-code compiler that runs on most platforms.
GHC is noted for its rich type system incorporating recent innovations such as generalized algebraic data types and type families.
The Computer Language Benchmarks Game also highlights its high-performance implementation of concurrency and parallelism.
An implementation of an algorithm similar to quick sort over lists, where the first element is taken as the pivot: GHC is also distributed with the Haskell platform. It is implemented using attribute grammars and is currently used mostly for research on generated type systems and language extensions.
Jhc, a Haskell compiler written by John Meacham, emphasizes speed and efficiency of generated programs and exploring new program transformations. Ajhc is a fork of Jhc. Implementations no longer actively maintained include: It was once one of the implementations used most widely, alongside the GHC compiler,  but has now been mostly replaced by GHCi.
It also comes with a graphics library. The York Haskell Compiler Yhc was a fork of nhc98, with the goals of being simpler, more portable and efficient, and integrating support for Hat, the Haskell tracer.
It was supplanted by Hugs see above. Helium is a newer dialect of Haskell. The focus is on making learning easier via clearer error messages.
It currently lacks full support for type classes, rendering it incompatible with many Haskell programs. Applications[ edit ] Darcs is a revision control system written in Haskell, with several innovative features, such as more precise control of patches to apply.
Cabal is a tool for building and packaging Haskell libraries and programs.
Pandoc is a tool to convert one markup format into another. The Shake build system, aiming to be reliable, robust, and fast. Cryptola language and toolchain for developing and verifying cryptography algorithms, is implemented in Haskell.Dependent Types in Practical (Extended Abstract) Programming* Hongwei Xi Department of Computer Science and Engineering Oregon Graduate Institute of Science and Technology grupobittia.com Frank Pfenning Department of Computer Science Carnegie Mellon University [email protected] Abstract We present an approach to enriching the type system of ML with a restricted form of dependent types, .
We believe that if dependent types are to be taken seriously in practical programming, and if programmers are to be encouraged to increase conﬁdence in program correctness through the type system, there must be more support at the type level for reasoning about invariants.
MASTERS THESIS "How applicable is Python as first computer language for teaching programming ever-changing needs of society that becomes increasingly dependent on technology. The reform is some of them are too simple to be practical, others are practical but hard to learn as a first programming skill.
Moreover, the most used ones among. In this paper, we show how Miquel’s Implicit Calculus of Constructions (ICC) can be used as a programming language featuring dependent types. Since this system has an undecidable type-checking, we introduce a more verbose variant, called ICC* which.
Jul 13, · 1 The concept of dependent types General. Wikipedia; Dependent Types in Programming abstract in APPSEM' Do we need dependent types? by Daniel Fridlender and Mia Indrika, Type theory. Simon Thompson: Type Theory and Functional Programming.
Norell, U.: Towards a practical programming language based on dependent type theory. PhD thesis, Chalmers University of Technology and Göteborg University () Google Scholar Sheard, T.: Putting Curry-Howard to work.