最近的Ruby for Rails读书笔记
1, 用"class <<"定义class methodclass User < ActiveRecord::Baseclass << selfdef authenticate(username, password) find_by_username(username, :conditions => )end
2, 用self.included(class)方法作为include模块的hooks
module Mdef self.included(c) puts "I have just been mixed into #{c}."endendclass Cinclude Mend
3, 用self.inherited(subclass)作为class继承的hooks
class Cdef self.inherited(subclass) puts "#{self} just got subclassed by #{subclass}"endendclass D < Cend
用self.const_missing(const)作为class缺失const的hooks
class Cdef self.const_missing(const) puts "#{const} is undefined-setting it to 1." const_set(const, 1)endendputs C::A
4, 用eval/instance_eval/class_eval(module_eval)动态执行程序
str = "hello"eval "str + ' Fred'"
5, 用Proc定义代码块
pr = Proc.new { |x| puts "Called with argument #{x}" }
6, 用lambda定义匿名方法
lam = lambda { puts "A lambda!" }lam.call
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