add some awesome enhanced RI functionality for irb

.irbrc

@@ -50,3 +50,92 @@ if ENV.include?('RAILS_ENV') && !Object.const_defined?('RAILS_DEFAULT_LOGGER')
   require 'logger'
   RAILS_DEFAULT_LOGGER = Logger.new(STDOUT)
 end
+
+# The below adds nice ri documentation via obj.ri_* with completion,
+# and supports the old Wirble way with `r 'String#count` and completion
+# as well. Courtesy:
+#
+#   http://eigenclass.org/hiki/irb+ri+completion
+#
+# The author recommends FastRI because RI is so slow.
+module Kernel
+  def r(arg)
+    puts `ri "#{arg}"`
+  end
+  private :r
+end
+
+class Object
+  def puts_ri_documentation_for(obj, meth)
+    case self
+    when Module
+      candidates = ancestors.map{|klass| "#{klass}::#{meth}"}
+      candidates.concat(class << self; ancestors end.map{|k| "#{k}##{meth}"})
+    else
+      candidates = self.class.ancestors.map{|klass|  "#{klass}##{meth}"}
+    end
+    candidates.each do |candidate|
+      #puts "TRYING #{candidate}"
+      # desc = `fri '#{candidate}'`
+      # unless desc.chomp == "nil"
+      # uncomment to use ri (and some patience)
+      desc = `ri -T '#{candidate}' 2>/dev/null`
+      unless desc.empty?
+        puts desc
+        return true
+      end
+    end
+    false
+  end
+  private :puts_ri_documentation_for
+
+  def method_missing(meth, *args, &block)
+    if md = /ri_(.*)/.match(meth.to_s)
+      unless puts_ri_documentation_for(self,md[1])
+        "Ri doesn't know about ##{meth}"
+      end
+    else
+      super
+    end
+  end
+
+  def ri_(meth)
+    unless puts_ri_documentation_for(self,meth.to_s)
+      "Ri doesn't know about ##{meth}"
+    end
+  end
+end
+
+RICompletionProc = proc{|input|
+  bind = IRB.conf[:MAIN_CONTEXT].workspace.binding
+  case input
+  when /(\s*(.*)\.ri_)(.*)/
+    pre = $1
+    receiver = $2
+    meth = $3 ? /\A#{Regexp.quote($3)}/ : /./ #}
+    begin
+      candidates = eval("#{receiver}.methods", bind).map do |m|
+        case m
+        when /[A-Za-z_]/; m
+        else # needs escaping
+          %{"#{m}"}
+        end
+      end
+      candidates = candidates.grep(meth)
+      candidates.map{|s| pre + s }
+    rescue Exception
+      candidates = []
+    end
+  when /([A-Z]\w+)#(\w*)/ #}
+    klass = $1
+    meth = $2 ? /\A#{Regexp.quote($2)}/ : /./
+    candidates = eval("#{klass}.instance_methods(false)", bind)
+    candidates = candidates.grep(meth)
+    candidates.map{|s| "'" + klass + '#' + s + "'"}
+  else
+    IRB::InputCompletor::CompletionProc.call(input)
+  end
+}
+#Readline.basic_word_break_characters= " \t\n\"\\'`><=;|&{("
+Readline.basic_word_break_characters= " \t\n\\><=;|&"
+Readline.completion_proc = RICompletionProc