hese are Haskell translations of Ninety-Nine Lisp Problems, which are themselves translations of Ninety-Nine Prolog Problems. If you want to work on one of these, put your name in the block so we know someone's working on it. Then, change n in your block to the appropriate problem number, and fill in the <Problem description>,<example in Haskell>,<solution in haskell> and <description of implementation> fields. Then be sure to update the status on this page to indicate that we have a solution!
12 hours ago by matijap29
Introductory tutorials, teaching you Haskell, how to use the School, and some common libraries
12 hours ago by matijap29
Lazy implementqtion of bytestringsToVectors by newhoggy · Pull Request #9 · haskell-works/hw-prim · GitHub
RT : Serendipity is when you make a function lazy for streaming and you find it runs twice as fast.
yesterday by etorreborre
Declarative equations, compositional strategies: solving differential systems with lazy splines
A simple Haskell encoding of Euler’s method of integration is presented. From this encoding, a general solver for continuous differential equations is developed, by way of lazy splines. Various
refinement strategies are introduced to improve accuracy. The result is a declarative, compositional library for solving differential
equations.
2 days ago by doneata
What Sequential Games, the Tychonoff Theorem, and the Double-Negation Shift have in Common
This is a tutorial for mathematically inclined functional programmers, based on previously published, peered reviewed theoretical work. We discuss a higher-type functional, written here in the functional programming language Haskell, which

1. optimally plays sequential games,
2. implements a computational version of the Tychonoff Theorem from topology, and
3. realizes the Double-Negation Shift from logic and proof theory.

The functional makes sense for finite and infinite (lazy) lists, and in the binary case it amounts to an operation that is available in any (strong) monad.

In fact, once we define this monad in Haskell, it turns out that this amazingly versatile functional is already available in Haskell, in the standard prelude, called sequence, which iterates this binary operation. Therefore Haskell proves that this functional is even more versatile than anticipated, as the function sequence was introduced for other purposes by the language designers, in particular the iteration of a list of monadic effects (but effects are not what we discuss here).

Checkout related resources as well:
http://www.cs.bham.ac.uk/~mhe/papers/msfp2010/
article  pdf  programming  haskell  mathematics  logic
2 days ago by doneata
A novel representation of lists and its applications to the function "reverse"
A representation of lists as first-class functions is proposed. Lists represented in this way can be appended together in constant time, and can be converted back into ordinary lists in time proportional to their length. Programs which construct lists using append can often be improved by using this representation. For example, naive reverse can be made to run in linear time, and the conventional ‘fast reverse’ can then be derived easily. Examples are given in KRC (Turner, 1982), the notation being explained as it is introduced. The method can be compared to Sleep and Holmström's proposal (1982) to achieve a similar effect by a change to the interpreter.