294 papers · page 12 of 15
Protecting confidentiality of data has become increasingly important for computing systems. Information-flow techniques have been developed over the years to achieve that purpose, leading to special-purpose languages that guarantee information-flow security in programs. However, …
The Haskell definition and implementation of read is far from perfect. In the first place read is not able to handle the associativities defined for infix operators. Furthermore, it puts constraints on the way show is defined, and especially forces it to generate far more parenth…
Circular programs are a powerful technique to express multiple traversal algorithms as a single traversal function in a lazy setting. In this paper, we present a shortcut deforestation technique to calculate circular programs. The technique we propose takes as input the compositi…
We describe the design, implementation and use of HPC, a tool-kit to record and display Haskell Program Coverage. HPC includes tools that instrument Haskell programs to record program coverage, run instrumented programs, and display information derived from coverage data in vario…
In this demonstration, we present an implementation of a modular synthesizer in Haskell using Yampa. A synthesizer, be it a hardware instrument or a pure software implementation, as here, is said to be modular if it provides sound-generating and sound-shaping components that can …
We present Harpy, a Haskell library for run-time code generation of x86 machine code. Harpy provides efficient generation of machine code, a convenient domain specific language for generating code and a collection of code generation combinators.
The use of typed intermediate languages can significantly increase the reliability of a compiler. By type-checking the code produced at each transformation stage, one can identify bugs in the compiler that would otherwise be much harder to find. Also it guarantees that any proper…
We propose an extension to list comprehensions that makes it easy to express the kind of queries one would write in SQL using ORDER BY, GROUP BY, and LIMIT. Our extension adds expressive power to comprehensions, and generalises the SQL constructs that inspired it. It is easy to i…
The Glasgow Haskell Compiler (GHC) has quite sophisticated support for concurrency in its runtime system, which is written in low-level C code. As GHC evolves, the runtime system becomes increasingly complex, error-prone, difficult to maintain and difficult to add new concurrency…
Quasiquoting allows programmers to use domain specific syntax to construct program fragments. By providing concrete syntax for complex data types, programs become easier to read, easier to write, and easier to reason about and maintain. Haskell is an excellent host language for e…
This paper describes the design and construction of a Haskell source-level debugger built into the GHCi interactive environment. We have taken a pragmatic approach: the debugger is based on the traditional stop-examine-continue model of online debugging, which is simple and intui…
Generic traversals over recursive data structures are often referred to as boilerplate code. The definitions of functions involving such traversals may repeat very similar patterns, but with variations for different data types and different functionality. Libraries of operations …
We develop a Haskell library for functional-logic programming, motivated by the implementation of Wired, a relational embedded domain-specific language for describing and analysing digital circuits at the VLSI-layout level. Compared to a previous library for logic programming by …
xmonad is a tiling window manager for the X Window system, implemented, configured and dynamically extensible in Haskell. This demonstration presents the case that software dominated by side effects can be developed with the precision and efficiency we expect from Haskell by util…
It can be very difficult to debug impure code, let alone prove its correctness. To address these problems, we provide a functional specification of three central components of Peyton Jones's awkward squad: teletype IO, mutable state, and concurrency. By constructing an internal m…
We propose a development methodology for designing and prototyping high assurance microkernels, and describe our application of it. The methodology is based on rapid prototyping and iterative refinement of the microkernel in a functional programming language. The prototype provid…
Modern functional languages offer several attractive features to support development of reliable and secure software. However, in our efforts to use Haskell for systems programming tasks-including device driver and operating system construction-we have also encountered some signi…
Numerical computations are often specified in terms of operations on vectors and matrices. This is partly because it is often natural to do so; but it is also partly because, being otherwise useful, such operations have been provided very fast implementations in linear algebra li…
We introduce the new, improved version of the Haskell Equational Reasoning Assistant, which consists of an Ajax application for rewriting Haskell fragments in their context, and an API for scripting non-trivial rewrites.
With my presentation I intend to demonstrate an implementation of breakpoint combinators in GHCi. These combinators are designed to aid the debugging process of Haskell programs by halting the execution and letting the user observe variables of their choice. In contrast to the ex…