Scala Functional Programming Patterns

Referential transparency

To understand referential transparency, let's first consider the following description:

Let me tell you a bit about India's capital, New Delhi. The Indian capital houses the Indian Parliament. The Indian capital is also home to Gali Paranthe Wali, where you get to eat the famous parathas.

We can also say the following instead:

Let me tell you a bit about India's capital, New Delhi. New Delhi houses the Indian Parliament. New Delhi is also home to Gali Paranthe Wali, where you get to eat the famous parathas.

Here, we substituted New Delhi with the Indian capital, but the meaning did not change. This is how we would generally express ourselves.

The description is referentially transparent with the following commands:

scala> def ...