&X
Ruby procs can be tiresome. &X (read as "ampersand ex") is a gem to vastly simplify this and bring expressiveness back to your code.
You'd use &X in places where you need a simple proc, but are too lazy to
type { |some_object| some_object.property.another > 42 } yourself.
There is &:method_name, but it wouldn't work with method chains and
arguments to each one. &X tries to fill the gap here.
First, unlike &:method_name, &X can handle hashes:
people = [ {name: "Patrick"}, {name: "Jane"}, {name: "Jack"}, {name: "Donald"} ]
# &X
people.map(&X[:name])
# plain ruby
people.map { |person| person[:name] }But it does not stop there. You can also apply some predicates on objects easily:
Person = Stuct.new(:first, :age)
patrick = Person.new("Patrick", 19)
jane = Person.new("Jane", 21)
jack = Person.new("Jack", 20)
donald = Person.new("Donald", 25)
people = [patrick, jane, jack, donald]
# plain ruby
people.partition { |person| person.age > 20 }
# with &X
people.partition(&X.age > 20)You can traverse a long chain of method calls too:
# Suppose we have a Person class with +address+ property,
# which, in turn, has +city+ and +street+ properties.
# We want to find all people older than 20 living in Chicago...
# plain ruby
people.select { |person| person.age > 20 && person.address.city == "Chicago" }
# &X
people.select(&X.age > 20).select(&X.address.city == "Chicago")Installation
Add this line to your application's Gemfile:
gem 'ampersand_x'
Or install it yourself as:
$ gem install ampersand_x
License
MIT.