Function composition

Ruby supports function composition of different Proc objects using << and >> operator, and a Proc object encapsulates a function [1].

function_composition.rb

func_1 = proc {|num| num + 2}
func_2 = proc {|num| num / num}
puts (func_1 << func_2).call(5)  # This is equivalent to the composition func_1(func_2(5))
puts (func_1 >> func_2).call(5)  # This is equivalent to the composition func_2(func_1(5))

Source code: https://github.com/yc015/Ruby-Inspect/blob/main/src/function_composition.rb

The codes above will print:

3
1

The codes above use operator << and >> to make function composition func_1(func_2(x)) and func_2(func_1(x)) where x is the input argument, 5 in this case.

Reference:
[1] https://medium.com/rubycademy/function-composition-in-ruby-d9ca64f65abb Function Composition in Ruby - Mehdi Farsi