# The Haskell Tool Stack Stack is a cross-platform program for developing Haskell projects. It is aimed at Haskellers both new and experienced. It features: * Installing GHC automatically, in an isolated location. * Installing packages needed for your project. * Building your project. * Testing your project. * Benchmarking your project. #### How to install For many Un*x operating systems, all you need to do is run: curl -sSL https://get.haskellstack.org/ | sh or: wget -qO- https://get.haskellstack.org/ | sh On Windows, you can download and install the [Windows 64-bit Installer](https://get.haskellstack.org/stable/windows-x86_64-installer.exe). For detailed instructions and downloads, including many additional operating systems, check out the [install and upgrade page](install_and_upgrade.md). #### Quick Start Guide First you need to [install it (see previous section)](#how-to-install). ##### Start your new project: ```bash stack new my-project cd my-project stack setup stack build stack exec my-project-exe ``` - The `stack new` command will create a new directory containing all the needed files to start a project correctly. - The `stack setup` will download the compiler if necessary in an isolated location (default `~/.stack`) that won't interfere with any system-level installations. (For information on installation paths, please use the `stack path` command.). - The `stack build` command will build the minimal project. - `stack exec my-project-exe` will execute the command. - If you just want to install an executable using stack, then all you have to do is `stack install `. If you want to launch a REPL: ```bash stack ghci ``` Run `stack` for a complete list of commands. ##### Workflow The `stack new` command should have created the following files: ``` . ├── LICENSE ├── Setup.hs ├── app │   └── Main.hs ├── my-project.cabal ├── src │   └── Lib.hs ├── stack.yaml └── test └── Spec.hs 3 directories, 7 files ``` So to manage your library: 1. Edit files in the `src/` directory. The `app` directory should preferably contain only files related to executables. 2. If you need to include another library (for example the package [`text`](https://hackage.haskell.org/package/text)): - Add the package `text` to the file `package.yaml` in the section `dependencies: ...`. - Run `stack build` another time. - `stack build` will update my-project.cabal for you. If desired you can update the .cabal file manually and stack will use .cabal instead of package.yaml. 3. If you get an error that tells you your package isn't in the LTS. Just try to add a new version in the `stack.yaml` file in the `extra-deps` section. That was a really fast introduction on how to start to code in Haskell using `stack`. If you want to go further, we highly recommend you to read the [`stack` guide](GUIDE.md). #### How to contribute This assumes that you have already installed a version of stack, and have `git` installed. 1. Clone `stack` from git with `git clone https://github.com/commercialhaskell/stack.git`. 2. Enter into the stack folder with `cd stack`. 3. Build `stack` using a pre-existing `stack` install with `stack setup && stack build`. 4. Once `stack` finishes building, check the stack version with `stack exec stack -- --version`. Make sure the version is the latest. 5. Look for issues tagged with [newcomer friendly](https://github.com/commercialhaskell/stack/issues?q=is%3Aopen+is%3Aissue+label%3a%22newcomer+friendly%22) and [awaiting pull request](https://github.com/commercialhaskell/stack/issues?q=is%3Aopen+is%3Aissue+label%3A%22awaiting+pull+request%22) labels. Build from source as a one-liner: ```bash git clone https://github.com/commercialhaskell/stack.git && \ cd stack && \ stack setup && \ stack build ``` If you need to check your changes quickly run: ```bash stack ghci λ: :main --stack-root /path/to/root/ --stack-yaml /path/to/stack.yaml COMMAND ``` This allows you to set a special stack root (instead of `~/.stack/`) and to target your commands at a particular `stack.yaml` instead of the one found in the current directory. #### Complete guide to stack This repository also contains a complete [user guide to using stack](GUIDE.md), covering all of the most common use cases. #### Questions, Feedback, Discussion * For frequently asked questions about detailed or specific use-cases, please see [the FAQ](faq.md). * For general questions, comments, feedback and support, please write to [the stack mailing list](https://groups.google.com/d/forum/haskell-stack). * For bugs, issues, or requests, please [open an issue](https://github.com/commercialhaskell/stack/issues/new). * When using Stack Overflow, please use [the haskell-stack tag](http://stackoverflow.com/questions/tagged/haskell-stack). #### Why Stack? Stack is a build tool for Haskell designed to answer the needs of Haskell users new and experienced alike. It has a strong focus on reproducible build plans, multi-package projects, and a consistent, easy-to-learn interface, while providing the customizability and power experienced developers need. As a build tool, Stack does not stand alone. It is built on the great work provided by: * The __Glasgow Haskell Compiler__ (GHC), the premier Haskell compiler. Stack will manage your GHC installations and automatically select the appropriate compiler version for your project. * The __Cabal build system__, a specification for defining Haskell packages, together with a library for performing builds. * The __Hackage package repository__, providing more than ten thousand open source libraries and applications to help you get your work done. * The __Stackage package collection__, a curated set of packages from Hackage which are regularly tested for compatibility. Stack defaults to using Stackage package sets to avoid dependency problems. Stack is provided by a team of volunteers and companies under the auspices of the [Commercial Haskell](http://commercialhaskell.com/) group. The project was spearheaded by [FP Complete](https://www.fpcomplete.com/) to answer the needs of commercial Haskell users, and has since become a thriving open source project meeting the needs of Haskell users of all stripes. If you'd like to get involved with Stack, check out the [newcomer friendly](https://github.com/commercialhaskell/stack/issues?q=is%3Aopen+is%3Aissue+label%3a%22newcomer+friendly%22) label on the Github issue tracker. #### How to uninstall Removing ``~/.stack`` and ``/usr/local/bin/stack`` should be sufficient. You may want to delete ``.stack-work`` folders in any Haskell projects that you have built.