Exploring Elixir 1.18's Enhancements in Type Checking

Elixir 1.18 ships with enhancements to the type system, specifically adding type checking for function calls and gradual inference for patterns and return types. This development allows for better compiler feedback when changing return values in functions. For instance, when a function's return value is altered, like changing from :error to {:error, :invalid_week}, users can receive warnings if they forget to update pattern matches in dependent modules. This notable improvement helps catch potential errors before code is deployed to production. However, limitations remain, particularly when dealing with dynamic argument passing to functions, which can obscure the compiler's ability to infer the expected return values accurately. Overall, these updates represent a significant step forward in Elixir's type system functionality.