Monad_Pattern

Monad

• It is a concept of functional programming
• They are containers that allow us to handle the effects outside the function’s scope, preserving the function’s purity.
• They enable us to focus on the main scenario and handle the corner cases outside of the main logic.
• Examples:
  • Optional
  • Stream or List
  • Future or Promise
  • Mono or CompletableFuture
  • Either
• References
  • https://www.youtube.com/watch?v=C2w45qRc3aU
  • https://java-design-patterns.com/patterns/monad/
  • https://www.baeldung.com/java-monads
  • https://en.wikipedia.org/wiki/Monad_(functional_programming)

Monad

• Monadic Type
• Operations
  • Unit — Type converter to Monadic Type
  • Bind — Can be chained together to give another Monads

Example

• Monadic Type: Optional<T>
• Operations:
  • Unit: Optional.ofNullable(x): converts x to Optional
  • Bind: flatMap(T -> Optional<U>) returns another Optional

If flatMap monadic, Is map also monadic?