如何在Ruby中模拟Java类注释？
(我们有答案,概括一下
http://bens.me.uk/2009/java-style-annotations-in-ruby)
解决方法
这几个星期前改编自
a piece of code I wrote in an answer to another question,虽然它当然不是原创的.毕竟,这是众所周知的Ruby惯用语,多年来一直在使用,至少从耙子的描述法开始.
module Annotations
def annotations(meth=nil)
return @__annotations__[meth] if meth
@__annotations__
end
private
def method_added(m)
(@__annotations__ ||= {})[m] = @__last_annotation__ if @__last_annotation__
@__last_annotation__ = nil
super
end
def method_missing(meth,*args)
return super unless /\A_/ =~ meth
@__last_annotation__ ||= {}
@__last_annotation__[meth[1..-1].to_sym] = args.size == 1 ? args.first : args
end
end
class Module
private
def annotate!
extend Annotations
end
end
这里有一个小例子：
class A annotate! _hello color: 'red',ancho: 23 _goodbye color: 'green',alto: -123 _foobar color: 'blew' def m1; end def m2; end _foobar color: 'cyan' def m3; end end
当然,没有一个testuite,Ruby代码将不会完成：
require 'test/unit'
class TestAnnotations < Test::Unit::TestCase
def test_that_m1_is_annotated_with_hello_and_has_value_red
assert_equal 'red',A.annotations(:m1)[:hello][:color]
end
def test_that_m3_is_annotated_with_foobar_and_has_value_cyan
assert_equal 'cyan',A.annotations[:m3][:foobar][:color]
end
def test_that_m1_is_annotated_with_goodbye
assert A.annotations[:m1][:goodbye]
end
def test_that_all_annotations_are_there
annotations = {
m1: {
hello: { color: 'red',ancho: 23 },goodbye: { color: 'green',alto: -123 },foobar: { color: 'blew' }
},m3: {
foobar: { color: 'cyan' }
}
}
assert_equal annotations,A.annotations
end
end