Scala Monad - Full worked example [closed]

Question

Does anyone have a full worked example of a Scala monad that tackles a real-world problem and has comparisons to the same code written in Java?

Answer 1

All collections are monads (that's a general statement, not a Scala-specific one), or "have monads" depending on how strict you want to be about it. Scala also has Option as a monad, and the right and left projections of Either as well. You can see their monadic aspects at work whenever you see a for-comprehension with them.

A more subtle example of monads in Scala is the parser combinators. It is more subtle because the operators hide the monadic operations behind synonyms that look better in a grammar.