NAME options.rb DESCRIPTION options.rb simplifies the common idiom of dealing with keyword options in ruby functions. it also deals correctly with symbol vs string keywords and prevents many subtle programming errors that can arise from doing so incorrectly. options.rb doesn't hack ruby's core with one exception: the method Array#options. SYNOPSIS require 'options' def method(*args, &block) args, options = Options.parse(args) a = args.shift b = args.shift force = options.getopt(:force, default = false) verbose = options.getopt([:verbose, :VERBOSE]) foo, bar = options.getopt(:foo, :bar) end INSTALL gem install options SAMPLES <========< samples/a.rb >========> ~ > cat samples/a.rb require 'options' # options.rb makes it super easy to deal with keyword options in a safe and # easy way. # def method(*args) args, options = Options.parse(args) force = options.getopt(:force, default=false) p force end method(:foo, :bar, :force => true) method('force' => true) ~ > ruby samples/a.rb true true <========< samples/b.rb >========> ~ > cat samples/b.rb require 'options' # options.rb avoids common mistakes made handling keyword arguments # def broken(*args) options = args.last.is_a?(Hash) ? args.pop : {} if options[:force] puts 'forcing' else puts 'broken' end end def nonbroken(*args) args, options = Options.parse(args) if options.getopt(:force) puts 'nonbroken' end end broken('force' => true) nonbroken('force' => true) def fubar(*args) options = args.last.is_a?(Hash) ? args.pop : {} verbose = options[:verbose] || true if verbose if options[:verbose] puts 'verbosely' else puts 'fubar' end end end def nonfubar(*args) args, options = Options.parse(args) verbose = options.getopt(:verbose) if verbose puts 'verbosely' else puts 'nonfubar' end end fubar(:verbose => false) nonfubar(:verbose => false) ~ > ruby samples/b.rb broken nonbroken fubar nonfubar <========< samples/c.rb >========> ~ > cat samples/c.rb require 'options' # options.rb hacks ruby core in exactly one way - the method Array#options # def method(*args) options = args.options p :args => args p :options => options end method(:a, :b, :k => :v) def method2(*args) options = args.options.pop p :args => args p :options => options end method2(:a, :b, :k => :v) ~ > ruby samples/c.rb {:args=>[:a, :b, {:k=>:v}]} {:options=>{:k=>:v}} {:args=>[:a, :b]} {:options=>{:k=>:v}} <========< samples/d.rb >========> ~ > cat samples/d.rb require 'options' # options.rb makes it easy to provide good error messages when people # misuse a method. # def method(*args) args, options = Options.parse(args) options.validate(:force) force = options.getopt(:force, default=false) p force end method(:foo, :bar, :force => true) ~ > ruby samples/d.rb true