294 papers · page 7 of 15
There are at present two ways to write GUIs for functional code. One is to use standard GUI toolkits, with all the benefits they bring in terms of feature completeness, choice of platform, conformance to platform-specific look-and-feel, long-term viability, etc. How- ever, such G…
We present an encoding of full linear lambda calculus in Haskell using higher order abstract syntax. By making use of promoted data kinds, multi-parameter type classes and functional dependencies, the encoding allows Haskell to do both linear type checking and linear type inferen…
The machine learning community has recently shown a lot of interest in practical probabilistic programming systems that target the problem of Bayesian inference. Such systems come in different forms, but they all express probabilistic models as computational processes using synta…
Type classes and type families are key ingredients in Haskell programming. Type classes were introduced to deal with ad-hoc polymorphism, although with the introduction of functional dependencies, their use expanded to type-level programming. Type families also allow encoding typ…
Haskell, as implemented by the Glasgow Haskell Compiler (GHC), allows expressive type-level programming. The most popular type-level programming extension is TypeFamilies, which allows users to write functions on types. Yet, using type functions can cripple type inference in cert…
Using static analysis techniques compilers for lazy functional languages can be used to identify parts of a program that can be legitimately evaluated in parallel and ensure that those expressions are executed concurrently with the main thread of execution. These techniques can p…
Systematic concurrency testing (SCT) is an approach to testing potentially nondeterministic concurrent programs. SCT avoids potentially unrepeatable results that may arise from unit testing concurrent programs. It seems to have received little attention from Haskell programmers. …
Several popular languages including Haskell and Python use the indentation and layout of code as an essential part of their syntax. In the past, implementations of these languages used ad hoc techniques to implement layout. Recent work has shown that a simple extension to context…
We report on our experience teaching a Haskell-based functional programming course to over 1100 students for two winter terms. The syllabus was organized around selected material from various sources. Throughout the terms, we emphasized correctness through QuickCheck tests and pr…
No abstract available.
Haskell, as implemented in the Glasgow Haskell Compiler (GHC), is enriched with many extensions that support type-level programming, such as promoted datatypes, kind polymorphism, and type families. Yet, the expressiveness of the type-level language remains limited. It is missing…
We propose a new programming model for web applications which is (1) seamless; one program and one language is used to produce code for both client and server, (2) client-centric; the programmer takes the viewpoint of the client that runs code on the server rather than the other …
Simple is a web framework for Haskell. Simple came out of our work on Hails, a platform for secure web applications. For Hails, we needed a flexible web framework that uses no unsafe language features and can be used to build apps outside the IO monad. Unlike many mainstream web …
The statelessness of functional computations facilitates both parallelism and fault recovery. Faults and non-uniform communication topologies are key challenges for emergent large scale parallel architectures. We report on HdpH and HdpH-RS, a pair of Haskell DSLs designed to addr…
As originally proposed, type classes provide overloading and ad-hoc definition, but can still be understood (and implemented) in terms of strictly parametric calculi. This is not true of subsequent extensions of type classes. Functional dependencies and equality constraints allow…
Many of the bugs in scientific programs have their roots in mistreatment of physical dimensions, via erroneous expressions in the quantity calculus. Now that the type system in the Glasgow Haskell Compiler is rich enough to support type-level integers and other promoted datatypes…
Most strongly typed, functional programming languages are not equipped with a reentrant garbage collector. Therefore such languages are not used for operating systems programming, where the virtues of types are most desired. We propose the use of Context-Local Heaps (CLHs) to ach…
Monads are now an everyday tool in functional programming for abstracting and delimiting effects. The link between monads and effect systems is well-known, but in their typical use, monads provide a much more coarse-grained view of effects. Effect systems capture fine-grained inf…
QuickCheck is a powerful library for automatic test-case generation. Because QuickCheck performs random testing, some of the counterexamples discovered are very large. QuickCheck provides an interface for the user to write shrink functions to attempt to reduce the size of counter…
A series of list appends or monadic binds for many monads performs algorithmically worse when left-associated. Continuation-passing style (CPS) is well-known to cure this severe dependence of performance on the association pattern. The advantage of CPS dwindles or disappears if w…