The process of writing large parallel programs is complicated by the need to specify both the parallel behaviour of the program and the algorithm that is to be used to compute its result.
What should you learn first, Lisp or Haskell? It depends entirely on your personality. One thing is certain - if you want to be a great developer eventually you'll have to learn both.
citeproc-hs is a library for automatically formatting bibliographic reference citations into a variety of styles using a macro language called Citation Style Language (CSL).
August 6, 2007 I am curious about the possibility of developing Haskell programs spontaneously with proofs about their properties and have the type checker verify the proofs for us, in a way one would do in a dependently typed language. In the exercise below, I tried to redo part of the merge-sort example in Altenkirch, McBride, and McKinna’s introduction to Epigram: deal the input list into a binary tree, and fold the tree by the function merging two sorted lists into one. The property I am going to show is merely that the length of the input list is preserved. To begin with, we define the usual type-level representation of natural numbers and lists indexed by their lengths.
One of the pleasant new features in GHC 6.10 is the long-awaited addition of view patterns. This feature is usually advertised as making it possible to pattern match against the values of an abstract type. An essential aspect of modular software design is that we don't want to expose the implementation of complex code. Someone will surely come along and start making decisions based on bits of our code that they can see, thus limiting our future room to manoeuvre. This is all amply explained on the view pattern wiki page and in the GHC User's Guide. how do they diff from f# active pats
This article is part three in a series on introductory Haskell programming. In the first article, we wrote a small program to recursively scan file-system directories and print their contents as ASCII-art trees. In the second article, we refactored the program to make its logic more reusable by separating the directory-scanning logic from the tree-printing logic. In this article, we will address a shortcoming of the refactored version: It must scan directory hierarchies completely before printing their trees, i.e., it must scan and then print, when doing both simultaneously is both more efficient and more user friendly. Recall from the previous article that our directory-printing program is factored into three pieces of logic:
1. What is a dependent type 1. ADT -- the simplest dependent-type 2. Singleton types 3. Branding: type proxies 2. Lightweight static capabilities 1. Abstract and Introduction 2. Formalization and proofs 3. Accompanying source code 3. The question of verification 4. Genuine Dependent-type systems This is a joint work with Chung-chieh Shan. We describe several approaches to lightweight dependent-type programming, letting us gain experience with dependent types on existing programming language systems All these lightweight approaches rely on type-level proxies for values, so we can statically express properties (e.g., equality, inequality) of the values that are not generally known until the run time. ``This much is clear: many programmers are already finding practical uses for the approximants to dependent types which mainstream functional languages (especially Haskell) admit, by hook or by crook.''