我希望能够在我的Ruby代码中编写lambda/Proc,将其序列化以便我可以将其写入磁盘,然后再执行lambda.有点像......
x = 40
f = lambda { |y| x + y }
save_for_later(f)
后来,在另一个Ruby解释器的运行中,我想能够说...
f = load_from_before
z = f.call(2)
z.should == 42
Marshal.dump不适用于Procs.我知道Perl有Data :: Dump :: Streamer,而在Lisp中这是微不足道的.但有没有办法在Ruby中做到这一点？换句话说,实施什么？save_for_later
编辑:我的答案很好,但它不会关闭自由变量(如x)并将它们与lambda序列化.所以在我的例子中......
x = 40
s = save_for_later { |y| x + y }
# => "lambda { |y|\n (x + y)\n}"
...字符串输出不包含的定义x.是否有一个解决方案考虑到这一点,可能是通过序列化符号表？你可以在Ruby中访问它吗？
编辑2:我更新了我的答案,以结合序列化局部变量.这似乎可以接受.
我正在尝试使用rails应用程序中的以下代码在会话中存储值
session[:key] = value
我得到以下错误
TypeError (no _dump_data is defined for class Proc):
activesupport (3.2.9) lib/active_support/message_verifier.rb:53:in `dump'
activesupport (3.2.9) lib/active_support/message_verifier.rb:53:in `generate'
actionpack (3.2.9) lib/action_dispatch/middleware/cookies.rb:300:in `[]='
actionpack (3.2.9) lib/action_dispatch/middleware/session/cookie_store.rb:67:in `set_cookie'
rack (1.4.1) lib/rack/session/abstract/id.rb:330:in `commit_session'
rack (1.4.1) lib/rack/session/abstract/id.rb:206:in `context'
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/cookies.rb:341:in `call'
activerecord (3.2.9) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.9) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
actionpack (3.2.9) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.9) lib/active_support/callbacks.rb:405:in `
任何帮助都非常感谢.