What is the point of the "method" method in Ruby?

Question

In Ruby, there is the "method" method, which creates a method object that you can then treat as a Proc. This is useful if you wish to do metaprogramming:

def foobar(method_as_a_string)
   2.method(method_as_a_string).call(2)
end

foobar("+")
=> 4

foobar("-")
=> 0

However, normally, if you want to do such meta-programming, you would use send instead of method...

def foobar(method_as_a_string)
   2.send(method_as_a_string, 2)
end

foobar("+")
=> 4

foobar("-")
=> 0

What is the point of the "method" method then in Ruby?

Answer 1

You can pass a method result to a block, and it will call the method passing the iteratee as arguments.

For example, this wouldn't work:

[1,2,3].each(&:puts)

because it's calling 1.puts, 2.puts, etc. But this would:

[1,2,3].each(&method(:puts))

Another example:

arr, result = [1,2,3], []
arr.each &result.method(:push)
result # => [1,2,3]

Another useful thing is using it to find the source location of a method:

Someclass.method(:some_method).source_location
# => this will give you the file & line where it's defined

This is a very helpful trick when you're working with gems and want to quickly glance at their source code

Answer 2

A Method object provides for all sorts of introspection and metaprogramming, including:

1. Getting the arity or parameters for the method
2. Getting the source code location for the method, which is useful in debugging or when writing tools that interact or inspect the source of the application that's running
3. Getting the receiver of the method

How and what you use those powers for is up to you.

---

For Cary, below:

"cat".method(:count).receiver
# => "cat"