文字列でメソッド呼び出しの使用例

load_config.rb

#!/usr/bin/env ruby

require 'optparse'
require 'ostruct'
require 'yaml'

mode = 'production'
 
ARGV.options do |o|
  o.on('-d', "--development") { |v| mode = 'development' }
  o.parse!
end
 
config = OpenStruct.new(File.open('config.yaml') { |f| YAML.load(f) })
server = config.method(mode).call

### case で書いた場合
case mode
when 'development'
  server = config.development
else
  server = config.production
end