Parsing FIT Files and Code Generation Using Elixir

Garmin developed a format called Flexible and Interoperable Data Transfer (FIT) used for storing activity data. Despite having many parsers available in different languages, the author decided to implement one in Elixir due to the powerful binary pattern matching capabilities of Erlang. Their initial approach using Elixir's Inspect protocol to convert data structures into strings for code generation proved to be suboptimal for debugging and function references. By leveraging Elixir's macros, the author achieved more readable and maintainable code generation, allowing for syntax validation and better integration with other Elixir code, including function calls and module creation. Ultimately, they improved their FIT file parser to be more reliable and plan to release it as an open-source library.