Applicative functors

Applicative functors are a concept in programming that allow you to apply functions wrapped inside a context (like a container or a computational effect) to values similarly wrapped. They enable combining multiple independent computations where both the functions and inputs are within these contexts, such as optional values, lists, or asynchronous operations. This pattern ensures that the context—like handling missing data or execution delays—is preserved throughout, making code more modular and expressive. In essence, applicative functors provide a structured way to apply functions to contextualized data without unpacking or losing the effect's meaning.