Ruby 2.0: What's New, Release History & Support Lifecycle

What Is New in Ruby 2.0

Ruby 2.0 introduced significant language refinements and performance enhancements. This release focused on making Ruby more expressive and efficient for developers.

How did keyword arguments improve method definitions?

Keyword arguments are a major syntax upgrade in Ruby 2.0. They allow defining methods with named parameters, making method calls clearer and more self-documenting.

You can define required and optional keyword arguments, which eliminates the need for parsing a final options hash. This makes APIs much more intuitive to use.

Example

def establish_connection(host:, port: 3306, ssl: false)
  # Method body
end

# Clear, explicit call
establish_connection(host: "db.example.com", ssl: true)

What is the purpose of Module#prepend?

Module#prepend provides a new way to mix modules into a class that takes precedence over the class's own methods. It inserts the module before the class in the ancestor chain.

This is powerful for overriding methods while still having access to the original implementation via super. It's a cleaner alternative to alias_method_chain patterns used in earlier versions.

Example

module Logging
  def execute
    puts "Starting..."
    super
  end
end

class Worker
  prepend Logging
  def execute
    # Actual work
  end
end

How do refinements change monkey-patching?

Refinements offer a scoped and controlled alternative to global monkey-patching. They allow you to modify classes within a specific module or file scope without affecting the entire application.

This addresses a major pain point in large codebases where conflicting monkey patches could cause subtle bugs. You activate refinements with the using keyword within a module or at the top of a file.

Example

module StringRefinements
  refine String do
    def shout
      upcase + "!"
    end
  end
end

# Only active within this module
module MyModule
  using StringRefinements
  "hello".shout # => "HELLO!"
end

What performance enhancements were included?

Ruby 2.0 brought several under-the-hood performance improvements. The virtual machine and garbage collector were optimized for better execution speed and memory usage.

Lazy symbol garbage collection helps with memory consumption in long-running processes. The require method also became faster, reducing application boot time.

What syntax shortcuts were added?

New literal syntaxes made code more concise. The %i notation creates arrays of symbols without needing multiple quotes and colons.

Default source encoding was changed to UTF-8, eliminating the need for magic comments in most files. This reflects Ruby's modern, international use cases.

Example

# Old way
symbols = [:foo, :bar, :baz]

# New in Ruby 2.0
symbols = %i(foo bar baz)