Understanding lambda functions

Most functional languages have a concept of a lambda function. It is an anonymous function defined inline. It can be assigned to a variable if needed. For example, consider that we need a function that accepts a cookie with user session data, in the context of a web application. Its job is to print a greeting to the user to the standard output. However, before printing, we need to decorate the user's name in a certain way. To complicate matters further, we also have a database of users who hold PhDs and, if they do, we need to refer to them as Dr. Here is how it can be done in Scala:

1. We define the dummy Cookie class for our example:

case class Cookie(name: String, gender: String)

2. We define the greeting method. The job of the method is to extract the data from the cookie object, and apply the modifier to the user's name based on their gender.
3. After that, greet the user. This method does not know how exactly to modify the name. The modifier logic is abstracted away...