What is the Writer Monad in Haskell?

Can you explain what the Writer Monad is in Haskell?

The Writer Monad is a type of monad that allows you to accumulate output alongside your computations. It's useful for logging or tracking additional information.

How does it differ from other monads like Maybe or List?

Unlike Maybe, which handles computations that might fail, and List, which represents non-deterministic computations, the Writer Monad accumulates values, allowing you to combine outputs.

Can you give me a simple example of using the Writer Monad?

Sure! Here's a simple example: you can use the Writer Monad to log messages while performing calculations. For instance, writer (3, "Calculated 3") would return a value of 3 with a log message.

What are some practical applications of the Writer Monad?

It's often used in scenarios like logging, where you want to keep track of operations without altering the main computation.