Functional programming (FP) is a paradigm that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. While Ruby is primarily an object-oriented language, it also offers several features that make functional programming possible and effective.
Key Concepts of Functional Programming
- Immutability: Avoiding changing the state of objects after they are created.
- First-Class and Higher-Order Functions: Treating functions as first-class citizens and using functions as arguments or return values.
- Pure Functions: Functions that have no side effects and return a value that depends only on their input.
- Function Composition: Building complex operations out of simpler functions.
Implementing Functional Programming in Ruby
- Leveraging Lambdas and Procs:
In Ruby, lambdas and procs are first-class functions that can be stored in variables, passed as arguments, or returned from other functions.
adder = ->(x, y) { x + y }
adder.call(2, 3) # => 5
- Using Immutable Data Structures:
While Ruby doesn’t enforce immutability, you can adopt a functional style by avoiding mutation of objects.