ICFP

We present a technique for integrating GHC's type-checker with an SMT solver. The technique was developed to add support for reasoning about type-level functions on natural numbers, and so our implementation uses the theory of linear arithmetic. ...

Typed functional programming and units of measure are a natural combination, as F# ably demonstrates. However, encoding statically-checked units in Haskell’s type system leads to inevitable disappointment with the usability of the resulting system. ...

A benefit of pure functional programming is that it encourages equational reasoning. However, the Haskell language has lacked direct tool support for such reasoning. Consequently, reasoning about Haskell programs is either performed manually, or in ...

We prove that the Call Arity analysis and transformation, as implemented in the Haskell compiler GHC, is safe, i.e. does not impede the performance of the program. We formalized syntax, semantics, the analysis and the transformation in the interactive ...

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 ...

Remote Procedure Calls are expensive. This paper demonstrates how to reduce the cost of calling remote procedures from Haskell by using the remote monad design pattern, which amortizes the cost of remote calls. This gives the Haskell community access ...

Extensible variants improve the modularity and expressiveness of programming languages: they allow program functionality to be decomposed into independent blocks, and allow seamless extension of existing code with both new cases of existing data types ...

This paper presents Modular Reifiable Matching (MRM): a new approach to two level types using a fixpoint of list-of-functors representation. MRM allows the modular definition of datatypes and functions by pattern matching, using a style similar to the ...

We present a rational reconstruction of extensible effects, the recently proposed alternative to monad transformers, as the confluence of efforts to make effectful computations compose. Free monads and then extensible effects emerge from the ...

A piece of functional programming folklore due to Piponi provides Löb's theorem from modal provability logic with a computational interpretation as an unusual fixed point. Interpreting modal necessity as an arbitrary Functor in Haskell, the "type" of ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Ivory is a language that enforces memory safety and avoids most undefined behaviors while providing low-level control of memory- manipulation. Ivory is embedded in a modern variant of Haskell, as implemented by the GHC compiler. The main contributions ...

Embedded languages are often compiled at application runtime; thus, embedded compile-time errors become application runtime errors. We argue that advanced type system features, such as GADTs and type families, play a crucial role in minimising such ...