Rubinius 在哪里实现了 mixin？

Question

Rubinius 源代码中负责包含模块的代码在哪里？（具体而言，将模块放置为对象类的超类。）

Answer 1

如果您查看Module#include 的文档，您会发现它委托给Module#append_features：

在每个参数上以相反的顺序调用Module.append_features。

Module#append_features 的文档反过来（非常简要地）描述了默认 Ruby 混合算法的工作原理：

当这个模块包含在另一个模块中时，Ruby 在这个模块中调用append_features，并将mod 中的接收模块传递给它。 Ruby 的默认实现是将此模块的常量、方法和模块变量添加到 mod，如果此模块尚未添加到 mod 或其祖先之一。另见Module#include。

如果您查看Rubinius sourcecode 中的Module#append_features，您会发现它是Module#include_into 的别名：

# Called when this Module is being included in another Module.
# This may be overridden for custom behaviour. The default
# is to add constants, instance methods and module variables
# of this Module and all Modules that this one includes to +klass+.
#
# See also #include.
#
alias_method :append_features, :include_into

所以，最后，Module#include_into 是真正的交易：

# Add all constants, instance methods and module variables
# of this Module and all Modules that this one includes to +klass+
#
# This method is aliased as append_features as the default implementation
# for that method. Kernel#extend calls this method directly through
# Module#extend_object, because Kernel#extend should not use append_features.
def include_into(klass)
  ...

您的具体问题：

正好将模块作为对象类的超类

在this loop回复：

k = klass.direct_superclass
while k
  if k.kind_of? Rubinius::IncludedModule
    # Oh, we found it.
    if k == mod
      # ok, if we're still within the directly included modules
      # of klass, then put future things after mod, not at the
      # beginning.
      insert_at = k unless superclass_seen
      add = false
      break
    end
  else
    superclass_seen = true
  end

  k = k.direct_superclass
end

关注insert_at。