972 5 Trying to understand metaclasses trying to understand metaclasses 2011-03-23 00:12:24 2011-03-23 00:18:43 {{{ class A def self.aa puts 'a' end class << self def ab puts 'b' end end end def mets(x); puts x.methods.select{|m| m=~/^a.$/}.sort.join(', '); end def imets(x); puts x.instance_methods.select{|m| m=~/^a.$/}.sort.join(', '); end a = A.new def A.ac puts 'c' end class A def self.ad puts 'd' end end class << a def self.ae puts 'e' end end class << A def af puts 'f' end end mets A mets a.eigenclass imets a.metaclass imets A.eigenclass imets a.eigenclass.eigenclass }}} Conclusion: Class methods defined in A are not A methods; they're A eigenclass methods (= A instance metaclass methods). Instance methods defined in A are A methods or A instance eigenclass methods? => Answer: A methods. 1 0 0 0 0 language Ruby 1 language English 1