Mastering Functional Programming

Declarative programming in other languages

In other modern languages, such as Haskell or Python, a similar declarative functionality is also present out of the box. For example, you can perform filtering in Python—it is built into the language, and you have a special function in Haskell to perform the same filtering. Also, the functional nature of Python and Haskell makes it easy to implement the same control structure as filtering by yourself. Both Haskell and Python support the notion of the lambda function and higher-order functions, so they can be used to implement declarative control structures.

In general, you can spot whether a language is declarative programming-friendly by looking at the capabilities it provides. Some of the features ...