MI-AFP Homework Elm #01

Homework to practice Elm language and the basics of The Elm Architecture.

Part I

The goal of this part is to practice the Elm language. There are several functions in the file src/Lib.elm waiting for your implementation. Each function has a documentation comment with a description of what it is supposed to do. There are also unit tests for these functions in tests/LibTest.elm which can help if something is unclear. You can run the tests using elm-test.

Most of the functions can be implemented using functions from elm/core modules, such as List, Maybe, String or Dict. For the last one, indexOf function, you should find appropriate package at package.elm-lang.org, install it and use it.

Part II

This part focuses on practising The Elm Architecture. The goal is to create a simple application that shows a story separated into three tabs (Introduction, Plot, Conclusion) with navigation between these tabs. When the app is opened, it should display the Introduction tab.

In the file src/Main.elm, there is already a structure for the application prepared. Your goal is to

• Define necessary messages you need for your implementation,
• Define the type for the Model and implement init function to return initial Model,
• Implement the update function to update the model correctly according to the message,
• Update view functions to
  • Dispatch messages when clicking on tabs,
  • Display correct content based on active tab,
  • Use tabStyleActive for active tab.

To open the application in the web browser, use elm reactor then navigate to http://localhost:8000 and open the Main.elm file.