Ruby Metaprogramming的一次公司分享活动

主要介绍了Ruby Metaprogramming的机制和方法。主要包括：
Introspection
Dynamic dispatch/Dynamic method
Ghost Method
Ruby Alias and AOP
Object/Class Extension
Eval/Class Eval/Instance Eval/Module Eval
Ruby Object Model
Singleton class/Metaclass/Eigenclasses
Hook Method
Module and Class Mixin Extension
Block、Callable Object and Functional programming
Domain Specific Language

另附带两段代码没往ppt写：
Open class and sexy api:

#!/usr/bin/ruby

class Numeric
    def weeks
        return 7 * self.days
    end
    
    def days
        return 24 * self.hours 
    end

    def hours
        return 60 * self.minutes
    end

    def minutes
        return 60 * self.seconds
    end

    def seconds
        return self
    end

    def ago
        return Time.now - self
    end

    def after
        return Time.new + self
    end
end

p 3.minutes.ago
p 3.days.ago
p 3.days.after

class macro:

class Object
    def self.my_attr_accessor(sym)
        class_eval <<EOF
            def #{sym}
                instance_variable_get(:@#{sym})
            end

            def #{sym}=(value)
                instance_variable_set(:@#{sym},value)
            end
EOF
    end
end

class A
    my_attr_accessor :a

    def initialize(a)
        @a = a
    end
end

a_ins = A.new(1)
a_ins.a = 22

puts a_ins.a

附件有ppt