echo-app-cabal

A simple Haskell project created with cabal init, showcasing a clean structure with library, executable, and test suite components.

This repository accompanies two lessons from the Software Library Design and Implementation course:

• 📘 Creating a Basic Project in Haskell with Cabal

• 📘 Structuring a Haskell Project with Multiple Modules

• Lesson Language: Spanish

• Code and Repo Language: English (to improve accessibility)

The goal is to provide a minimal but well-structured foundation for learning how to organize and build Haskell projects using Cabal and GHCup, with a focus on clean architecture and modularity.

📦 Project Structure

echo-app-cabal/
├── app/                 # Executable entry point
│   └── Main.hs
├── src-lib/             # Library source code
│   └── Echo.hs
├── test/                # Test suite
│   └── Main.hs
├── echo-app-cabal.cabal # Project definition
└── LICENSE              # License (BSD-2-Clause)

🚀 Quick Start

1. Install GHCup (if not already installed)

• macOS:

  brew install ghcup

• Linux:

  curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh

• Windows (with Scoop):

  scoop install ghcup

2. Install tools

ghcup install ghc
ghcup install cabal

On Windows, you may need to manually add GHC's bin directory to your PATH. The lessons explain how to do this with PowerShell.

3. Run the app

cabal run echo-app-cabal -- "Hi Barbie!" "Hi Ken!" "Do you guys ever think about dying?"

Expected output:

Hi Barbie!
Hi Ken!
Do you guys ever think about dying?

🧪 Running Tests

cabal test

✍️ About the Lessons

This project was initialized interactively using cabal init, with both lessons guiding you through:

• Choosing project layout and .cabal specification
• Separating reusable logic into a library (src-lib)
• Configuring an executable to consume the library
• Passing arguments from the terminal
• Preparing for testing by including a test suite early

The lessons go beyond just running commands: they explain the reasoning behind each choice and how to make your project modular and extensible from the start.

📚 References

• 📘 Cabal User’s Guide
• 📘 GHCup Installation Guide
• 📘 DIBS Course – Official Website

⚖️ License

BSD-2-Clause © Ignacio Slater Muñoz