Internal data structures are initialized.On Windows 95/NT, the registry is also queried for Hugs option settings. The variable HUGSFLAGS holds these options. Options in the environment are processed.When Hugs starts, the interpreter performs the following tasks: These options are distinguished by a leading + or - and are used to customize the behavior of the interpreter. Hugs uses options to set system parameters. (This manual assumes that Hugs has already been successfully installed on your system.) On Windows, Hugs may be started by selecting it from the start menu or by double clicking on a file with the. On Unix machines, the Hugs interpreter is usually started with a command line of the form: hugs. Presumably if you're using a system which isn't otherwise supported, you know enough about your system to be able to run configure scripts and make things by hand. For source first gunzip the file, then untar it. ![]() For RPMs use whatever RPM installation program you know best.From there, just follow the on-screen instructions. Simply choose "Run This Program" and the installation will begin automatically. For Windows when you click on the "msi" file to download,.Once you've downloaded Hugs, installation differs depending on your platform, however, installation for Hugs is more or less identical to installation for any program on your platform. From that page, you can download the appropriate version of Hugs for your computer. If you go there, there is a link titled "downloading" which will send you to the download page. Hugs supports almost all of the Haskell 98 standard (it lacks some of the libraries), as well as a number of advanced/experimental extensions, including: multi-parameter type classes, extensible records, rank-2 polymorphism, existentials, scoped type variables, and restricted type synonyms. It may have changed - see the Haskell website for up-to-date information. However, that is a fair amount to download and install, so if you had to go with just one, I'd get GHC, since it contains both a compiler and interactive environment.įollowing is a description of how to download and install each of these as of the time this tutorial was written. I tend to use GHC to compile (primarily because I'm most familiar with it) and the Hugs interactive environment, since it is much faster. I, personally, have all of them installed and use them for different purposes. NHC - less used and no interactive environment, but produces smaller and often faster executables than does GHC supports Haskell98 and some extensions.It also allows compiled objects to be loaded and tested. GHC - interactive environment is slower than Hugs to load, but allows function definitions in the environment (in Hugs you have to put them in a file) implements all of Haskell 98 and extensions good support for interfacing with other languages in a sense the "de facto" standard.Hugs - very fast to load files, slow to run them implements almost all of Haskell 98 (the standard) and most extensions built-in support for module browsing cannot create stand-alones written in C works on almost every platform built-in graphics library.I've tried to make a list of some of the differences in the following list but of course this is far from exhaustive: GHC is both an interpreter (like Hugs) and a compiler which will produce stand-alone programs. Hugs is exclusively an interpreter, meaning that you cannot compile stand-alone programs with it, but can test and debug programs in an interactive environment. If the term "data race" is familiar to you, I don't need to convince you any more.There are three well known Haskell systems: Hugs, GHC and NHC. In fact I was virtually pushed into functional programming by the necessities of concurrency. This is a nice thing in general, but it's a real life saver once you decide to write concurrent or parallel programs. ![]() ![]() ![]() For instance, it gives you full control over side effects. This is technically true, in the sense that Haskell is able to reduce all imperative programming to pure functions, but in practice Haskell is the best imperative language that there is. This is not true, and you'll find no high math in this series of tutorials.Īnother myth is that you can't do imperative programming in Haskell. One such myth is that you have to know advanced mathematics (category theory in particular) to be a good Haskell programmer. There are many myths about functional programming, and Haskell in particular, that have no basis in reality. Since I came from an imperative background - I can write some mean C++ code - I'm familiar with the potential obstacles in embracing Haskell. If you have some familiarity with functional programming, that's even better. The prerequisite for this series of tutorials is some knowledge of imperative programming, whether C++, Java, Pascal, you name it. A gentle introduction to Haskell for beginners.
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