Find the result of an evaluation in an Enumberable

Ruby allows mapping through an array to return a transformed array based on an evaluation in the block. It also allows finding a value in an array.

Ruby unfortunately does not have a single method that allows you to do both, i.e. loop through a list and return the first transformed value that meets a truthy condition.

To achieve this, we can leverage Ruby’s lazy enumerability.

my_val = 5
arr    = [->(val) { val * 3 }, ->(val) { val * 2 }, ->(val) { val * 7 }]

arr.lazy
   .map  { |my_proc|  my_proc.call(my_val) }
   .find { |proc_val| proc_val % 10 == 0 }
 # => 10 (the returned value of the second element
 # in the list. Element 3 is not processed.

Many thanks to Dylan Bridgman (@dylanbr) from the #ruby channel on the ZATech Slack for sharing this neat method.