Defines a 'chain' operation to apply a function that takes a simple value and outputs a new Chainable to a value inside a Chainable.

Something that is Chainable also needs to be Appliable.

Fruit Salad Example

There is one problem we haven't covered yet: What if you have an operation that itself returns a bowl?

Say we have a 'blend' operation, that takes an apple, and returns a bowl with apple juice.

If we would just map 'blend' over a bowl of apples, we would end up putting all the bowls of apple juice inside our original bowl.

This is clearly not what we want. Instead, we want to combine the results together back into a single bowl.

The implementation that tells how to do this, is called chain. For bowls, it would be 'put/pour contents of resulting bowl back into original bowl and forget about the other bowl.'

In Other Environments

• in Haskell, chain is known by the name bind, or >>=.