关于rails上的ruby：在模块中声明一个类

Declaring a class within a module

测量工作代码(在一个名为Surveyor的模块中，不能少)，试图理解它。我跑过这个包含模块中的类的部分。这和包含模块一样吗？如果没有，这样做有什么好处？谢谢。 (奖励要点：为什么我们将自己附加到课堂上，是不是已经隐含了？)

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module Surveyor
class Common
RAND_CHARS = [('a'..'z'), ('A'..'Z'), (0..9)].map{|r| r.to_a}.flatten.join
OPERATORS = %w(== != < > <= >= =~)

class << self
def make_tiny_code(len = 10)
if RUBY_VERSION <"1.8.7"
(1..len).to_a.map{|i| RAND_CHARS[rand(RAND_CHARS.size), 1] }.join
else
len.times.map{|i| RAND_CHARS[rand(RAND_CHARS.size), 1] }.join
end
end

def to_normalized_string(text)
words_to_omit = %w(a be but has have in is it of on or the to when)
col_text = text.to_s.gsub(/(<[^>]*>)|
|\t/su, ' ') # Remove html tags
col_text.downcase! # Remove capitalization
col_text.gsub!(/"|\'/u, '') # Remove potential problem characters
col_text.gsub!(/\(.*?\)/u,'') # Remove text inside parens
col_text.gsub!(/\W/u, ' ') # Remove all other non-word characters
cols = (col_text.split(' ') - words_to_omit)
(cols.size > 5 ? cols[-5..-1] : cols).join("_")
end

def equal_json_excluding_wildcards(a,b)
return false if a.nil? or b.nil?
a = a.is_a?(String) ? JSON.load(a) : JSON.load(a.to_json)
b = b.is_a?(String) ? JSON.load(b) : JSON.load(b.to_json)
deep_compare_excluding_wildcards(a,b)
end
def deep_compare_excluding_wildcards(a,b)
return false if a.class != b.class
if a.is_a?(Hash)
return false if a.size != b.size
a.each do |k,v|
return false if deep_compare_excluding_wildcards(v,b[k]) == false
end
elsif a.is_a?(Array)
return false if a.size != b.size
a.each_with_index{|e,i| return false if deep_compare_excluding_wildcards(e,b[i]) == false }
else
return (a =="*") || (b =="*") || (a == b)
end
true
end

alias :normalize :to_normalized_string

def generate_api_id
UUIDTools::UUID.random_create.to_s
end
end
end
end

what is the advantage of doing it this way?

它充当命名空间，因此具有相同名称的类不会发生冲突(因此它与mixin无关)。这是标准的。

Why are we appending self to class, is that not already implied?

这只是定义类方法的方法之一(另一种是def self.method_name)。