一个类别的Scoped猴子补丁

Question

我需要修补一个类，但希望该修补程序是某些模块的本地修补程序。在Ruby中，我会做：

module ArrayExtension
refine Array do
def ===(other)
self.include?(other)
end
end
end
module Foo
using ArrayExtension
def self.foo
case 2
when [1,2] then puts "bingo!"
end
end
end
Foo.foo          # => bingo!
puts [1,2] === 2 # => false

Crystal有类似的东西吗？

Answer 1

所以要重新定义===，只需重新定义它。

module Foo
def ===(other)
self.includes?(other)
end
end
class CustomArray(T) < Array(T)
include Foo
end
custom_array = CustomArray(Int32).new
custom_array << 1
custom_array << 2
puts custom_array === 1 # true
puts custom_array === 2 # true
puts custom_array === 3 # false