This gem redefines Ruby's unary +
operator to turn null objects into nil. By default, the unary +
operator is rarely¹ used by Ruby, so overloading it is not so dangerous as it might have sounded to you when you read it.
Every object that returns true for null?
is considered a null object.
¹ (Ruby 2.3 introduced +
for String: It will return an unfrozen version of the string)
Add to your Gemfile:
gem "null_plus"
class NullObject
def null?
true
end
end
null = NullObject.new
+nil #=> nil
+null #=> nil
+"some object" #=> "some object"
# Useful for settings defaults or checking conditions:
if +null
fail # will not run
end
value = +null || 42 #=> 42
Pay attention to proper operator precedence when chaining method class:
class NullObject
def null?
true
end
end
null = NullObject.new
+null.class #=> NullObject
(+null).class #=> NilClass
Copyright (C) 2015 Jan Lelis https://janlelis.com. Released under the MIT license.