**Course Title:** Functional Programming with Haskell: From Fundamentals to Advanced Concepts **Section Title:** Haskell Deployment and Ecosystem **Topic:** Creating executables with Stack and Cabal **Topic Overview** As a functional programming enthusiast, you've made it this far in the course and learned about various aspects of Haskell. By now, you're probably eager to share your Haskell programs with others, either as executables or libraries. This topic will walk you through the process of creating executables with Stack and Cabal, two popular tools in the Haskell ecosystem. **Why Stack and Cabal?** Before we dive into the details, let's understand the importance of Stack and Cabal. Both tools help you manage dependencies, build, and package your Haskell projects. They simplify the process of creating executables and libraries, making it easier to share your work with others. **Stack vs. Cabal** While both tools perform similar tasks, there are some key differences between them: * **Stack**: A more modern and user-friendly tool that focuses on reproducibility and simplicity. It's well-suited for applications and projects that require specific versions of dependencies. * **Cabal**: A more mature tool that's been around since the early days of Haskell. It offers more flexibility and fine-grained control but can be more complicated to use. **Creating Executables with Stack** Stack uses a `stack.yaml` file to configure your project. Here's an example step-by-step guide to creating an executable with Stack: 1. Create a new directory for your project and navigate to it in your terminal/command prompt. 2. Initialize a new Stack project using the following command: ```bash stack new myproject ``` This will create a basic `myproject` directory structure with a `myproject.cabal` file. 3. In the `myproject.cabal` file, you'll find the `build-depends` section. This is where you specify the dependencies required by your project. For example, you might add `base` and `containers` to the list: ```cabal build-depends: base >= 4.14 && < 5 , containers >= 0.6.5.1 && < 0.7 ``` 4. Create a new Haskell file, e.g., `src/Main.hs`, and define your main function: ```haskell module Main where import Control.Monad (replicateM, replicateM_) import Data.Foldable (traverse_) import qualified Data.ByteString.Char8 as B main :: IO () main = print "Hello, World!" ``` This will serve as the entry point for your executable. 5. Finally, use the following command to build and run your executable: ```bash stack exec myproject-exe ``` **Creating Executables with Cabal** Cabal uses a `myproject.cabal` file to configure your project. Here's an example step-by-step guide to creating an executable with Cabal: 1. Create a new directory for your project and navigate to it in your terminal/command prompt. 2. Create a new `myproject.cabal` file with the following content: ```cabal name: myproject version: 0.1.0.0 build-type: Simple cabal-version: >= 1.10 executable myproject-exe hs-source-dirs: src ghc-options: -Wall build-depends: base >= 4.14 && < 5, containers >= 0.6.5.1 && < 0.7 main-is: Main.hs ``` This file specifies the project name, version, build type, Cabal version, and executable settings. 3. Create a new Haskell file, e.g., `src/Main.hs`, and define your main function (similar to the example in the Stack section). 4. Build your executable using the following command: ```bash cabal configure cabal build ``` This will generate an executable file in the `dist-newstyle` directory. 5. Run your executable using the following command: ```bash ./dist-newstyle/build/myproject-exe/myproject-exe ``` **Conclusion** In this topic, we explored the process of creating executables with Stack and Cabal. You learned how to configure your projects, build executables, and run them using these popular tools in the Haskell ecosystem. **Additional Resources** * [Stack documentation](https://docs.haskellstack.org/en/stable/README/) * [Cabal documentation](https://cabal.readthedocs.io/en/latest/index.html) * [Haskell Wiki: Cabal](https://wiki.haskell.org/Cabal) * [Haskell Wiki: Stack](https://wiki.haskell.org/Stack) **Practice Exercise** Try creating executables for both Stack and Cabal projects. Experiment with different dependencies, configurations, and build settings. **Ask for Help** If you have any questions or need help with this topic, please leave a comment below.