Hiding Things in Ruby

Borrowing IIFE concept from Javascript to limit access using closures

Transcript

1. @devpuppy Hiding Things IIFE Ruby
2. @devpuppy IIFE Immediately-Invoked Function Expression (pronounced “iffy”)
3. @devpuppy IIFE in JS var getNumber; var setNumber; (function() { var number = 0; // lives inside the scope getNumber = function() { return number; } setNumber = function(value) { return number = value; } })();
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5. @devpuppy IIFE in Ruby get_number = nil set_number = nil -> { number = 0 get_number = -> { number } set_number = ->(value) { number = value } }.()
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7. @devpuppy an Elevator in a building with no basement
8. @devpuppy class Elevator attr_accessor :floor def initialize @floor = 1 end # override setter to prevent basement def floor=(value) raise "No basement" if value.to_i < 1 @floor = value end end
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11. @devpuppy class Elevator def initialize -> { floor = 1 define_singleton_method :floor= do |value| raise "No basement" if value.to_i < 1 floor = value end define_singleton_method :floor do floor end }.() end end
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13. @devpuppy Thanks!