![IHaskell](https://raw.github.com/gibiansky/IHaskell/master/images/ihaskell-logo.png) IHaskell === IHaskell is an implementation of the [IPython](http://ipython.org) kernel protocol which allows you to use Haskell inside IPython frontends such as `qtconsole` and `notebook`. [Demo Notebook](http://gibiansky.github.io/IHaskell/demo.html) --- The project works with the IPython shell: ![IPython Console](https://raw.github.com/gibiansky/IHaskell/master/images/ihaskell-console.png) As well as the IPython browser-based notebook interface: ![IPython Notebook](https://raw.github.com/gibiansky/IHaskell/master/images/ihaskell-notebook.png) *More usage information on the [wiki](https://github.com/gibiansky/IHaskell/wiki).* Installation === If you have any trouble with installation or have other questions about IHaskell, feel free to open an issue [on Github](https://github.com/gibiansky/IHaskell/issues?direction=desc&sort=updated&state=open) or join our IRC at #ihaskell on chat.freenode.net. ZeroMQ --- IHaskell uses a library known as ZeroMQ for asynchronous communication. Make sure that ZeroMQ 4 is installed - it is a relatively recent library and thus you may have older versions installed. For Macs, you can easily install it with [Homebrew](http://brew.sh/): ```bash # For Macs with Homebrew: brew update brew install zeromq ``` On other platforms, you can easily install from source: ```bash # Compiling from source: git clone git@github.com:zeromq/zeromq4-x.git libzmq cd libzmq ./autogen.sh && ./configure && make sudo make install sudo ldconfig ``` If your own platform has a package and I haven't included instructions for it, feel free to send me an email or a PR on this README. Haskell and Cabal --- You should also have GHC and modern Cabal: ```bash ghc --numeric-version # Should be 7.6.3 cabal --version # Should be 1.18.* ``` Since IHaskell uses the GHC API for evaluation and parsing, other versions of GHC may not work. If you do not have GHC or Cabal, you should be able to install both via the [Haskell Platform](http://www.haskell.org/platform/). On Macs with Homebrew, you can do this via ```bash # Macs with Homebrew only, if you don't have GHC or Cabal brew install haskell-platform cabal update && cabal install cabal-install ``` Use `cabal install cabal-install` to update Cabal if you still have version 1.16 instead of 1.18. Also, in order to use executables which `cabal` installs, they must be in your path. Execute this in your shell or add it to your `~/.bashrc`: ```bash # If you have a ~/.cabal/bin folder: export PATH=~/.cabal/bin:$PATH # If you have a ~/Library/Haskell/bin folder on OS X: export PATH=~/Library/Haskell/bin:$PATH ``` If you are using Mac OS X 10.9 (Mavericks) you will need to compile cairo with gcc, not clang. This can be done as follows: ```bash brew install gcc48 cabal install cairo --with-gcc=gcc-4.8 ``` Compilation Tools --- Install the `happy` parser generator tool and `cpphs` preprocessor: ```bash cabal install happy cpphs ``` IHaskell Installation --- Install the IHaskell package from Hackage: ```bash cabal install ihaskell ``` Running IHaskell --- Finally, run the notebook or console interface: ```bash IHaskell notebook # Should open a browser window! IHaskell console ``` There is a test notebook in the `IHaskell` directory. To try it, run IHaskell with `IHaskell notebook --serve=IHaskell`. If you get a pip error while IHaskell is installing Python dependencies on the first run (it will look like `EOFError: EOF when reading a line`), then you can do the following after ensuring that pip >= 1.5 is installed: ```bash env PIP_EXISTS_ACTION=w IHaskell notebook ``` If it *still* doesn't work and you are using Mac OS X then `brew upgrade python`. Some older versions of Homebrew's Python have a broken version of distutils. Homebrew's version of Python 2.7.6 *does* work. **Note**: You may have some trouble due to browser caches with the notebook interface if you also use IPython's notebook interface or have used it in the past. If something doesn't work or IPython says it can't connect to the notebook server, make sure to clear the browser cache in whatever browser you're using, or try another browser. Contributing === IHaskell is a young project, and I'd love your help getting it to a stable and useful point. There's a lot to do, and if you'd like to contribute, feel free to get in touch with me via my email at andrew period gibiansky at gmail - although browsing the code should be enough to get you started, I'm more than happy to answer any questions myself. **For package maintainers:** IHaskell has an ability to display data types it knows about with a rich format based on images or HTML. In order to do so, an external package `ihaskell-something` must be created and installed. Writing these packages is simply - they must just contain instance of the `IHaskellDisplay` typeclass, defined in `IHaskell.Display`, and for a package `ihaskell-something` should have a single module `IHaskell.Display.Something`. If you have a package with interesting data types that would benefit from a rich display format, please get in contact with me (andrew dot gibiansky at gmail) to write one of these packages! A sample package is available [here](https://github.com/gibiansky/IHaskell/tree/master/ihaskell-display/ihaskell-basic). Developer Notes --- Before diving in, you should read the [brief description of IPython kernel architectures](http://andrew.gibiansky.com/blog/ipython/ipython-kernels/) and read the [complete messaging protocol specification](http://ipython.org/ipython-doc/dev/development/messaging.html). Skim the rather-lacking [Haddock documentation](http://gibiansky.github.io/IHaskell/IHaskell/). First steps: - Fork the repository on Github and clone your fork for editing. **option 1** ```bash cd /path/to/IHaskell ./build.sh ``` **option 2** ```bash cd /path/to/IHaskell cabal sandbox init cabal sandbox add-source ipython-kernel ihaskell-display/* ghc-parser cabal install IHaskell $(basename ihaskell-display/*) ``` **Loading IHaskell into GHCi for testing:** Use one of the methods below to access IHaskell files in GHCi. Once inside GHCi, you can load an IHaskell file; for example, `:load IHaskell/Config.hs`. **Using cabal repl** If you have the latest version of cabal (>v1.18.0), the simplest thing to do is ```bash cd cabal repl ``` This will hide all packages not listed in `IHaskell.cabal` **Using GHCi directly** If you don't want to use `cabal repl`, you can just call ghci which can read the `.ghci` file included in the repository for the options. ```bash cd chmod 600 .ghci # trust the .ghci file ghci ``` Then in the ghci session you can type things like: ``` :set -package setenv :load src/Hspec.hs hspec parserTests :browse IHaskell.Types ```