blocks|key|3149186|text|Ruby有Marshal类，它有一个可以调用的dump方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3149187|看看这里：|3149188|http://rubylearning.com/satishtalim/object_serialization.html|offset|length|3149189|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|1P|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@$F|R|G|S|1|T]]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|E]]]]

Ruby has the Marshal class that has a dump method that you can call.
Take a look here:
<a href="http://rubylearning.com/satishtalim/object_serialization.html" rel="nofollow noreferrer">http://rubylearning.com/satishtalim/object_serialization.html</a>

blocks|key|363316|text|请查看this+question的答案。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|363317|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/23970/how-do-i-marshall-a-lambda-proc-in-ruby^0|3|D|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Check out the answers to <a href="https://stackoverflow.com/questions/23970/how-do-i-marshall-a-lambda-proc-in-ruby">this question</a>.

blocks|key|363335|text|使用Ruby2Ruby|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|363336|def+save_for_later(&block)
++return+nil+unless+block_given?

++c+=+Class.new
++c.class_eval+do
++++define_method+:serializable,+&block
++end
++s+=+Ruby2Ruby.translate(c,+:serializable)
++s.sub(/%5Edef+\S%2B$([%5E$]*)\)/,+'lambda+{+%7C\1%7C').sub(/end$/,+'}')
end

x+=+40
s+=+save_for_later+{+%7Cy%7C+x+%2B+y+}
#+=>+"lambda+{+%7Cy%7C\n++(x+%2B+y)\n}"
g+=+eval(s)
#+=>+#<Proc:0x4037bb2c@(eval):1>
g.call(2)+
#+=>+42|code-block|syntax|javascript|363337|这很棒，但它不会关闭自由变量(如x)，并将它们与lambda一起序列化。|CODE|363338|对于serialize+variables，您也可以遍历local_variables并序列化它们。然而，问题在于save_for_later中的local_variables只访问上述代码中的c和s+--即序列化代码的本地变量，而不是调用者。因此，不幸的是，我们必须将局部变量及其值的获取推送给调用者。|363339|也许这是一件好事，因为一般来说，在一段Ruby代码中找到所有自由变量都是undecidable。另外，理想情况下，我们还会保存global_variables和所有加载的类以及它们被覆盖的方法。这似乎不切实际。|363340|使用这种简单的方法，您将获得以下内容：|363341|def+save_for_later(local_vars,+&block)
++return+nil+unless+block_given?

++c+=+Class.new
++c.class_eval+do
++++define_method+:serializable,+&block
++end
++s+=+Ruby2Ruby.translate(c,+:serializable)
++locals+=+local_vars.map+{+%7Cvar,val%7C+"#{var}+=+#{val.inspect};+"+}.join
++s.sub(/%5Edef+\S%2B$([%5E$]*)\)/,+'lambda+{+%7C\1%7C+'+%2B+locals).sub(/end$/,+'}')
end

x+=+40
s+=+save_for_later(local_variables.map{+%7Cv%7C+[v,eval(v)]+})+{+%7Cy%7C+x+%2B+y+}
#+=>+"lambda+{+%7Cy%7C+_+=+40;+x+=+40;\n++(x+%2B+y)\n}"

#+In+a+separate+run+of+Ruby,+where+x+is+not+defined...
g+=+eval("lambda+{+%7Cy%7C+_+=+40;+x+=+40;\n++(x+%2B+y)\n}")
#+=>+#<Proc:0xb7cfe9c0@(eval):1>
g.call(2)
#+=>+42

#+Changing+x+does+not+affect+it.
x+=+7
g.call(3)
#+=>+43|363342|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/503583/how-do-you-access-the-symbol-table-in-ruby|1|http://en.wikipedia.org/wiki/Undecidable^0|0|B|0|0|G|1|0|S|F|1L|E|21|F|2P|1|2R|1|2|J|0|0|1R|G|10|B|1|0|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|18|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|19|8|@$9|1A|A|1B|B|M]]|D|@]|E|$]]|$1|N|3|O|5|6|7|1C|8|@$9|1D|A|1E|B|M]|$9|1F|A|1G|B|M]|$9|1H|A|1I|B|M]|$9|1J|A|1K|B|M]|$9|1L|A|1M|B|M]]|D|@$9|1N|A|1O|1|1P]]|E|$]]|$1|P|3|Q|5|6|7|1Q|8|@$9|1R|A|1S|B|M]]|D|@$9|1T|A|1U|1|1V]]|E|$]]|$1|R|3|S|5|6|7|1W|8|@]|D|@]|E|$]]|$1|T|3|U|5|H|7|1X|8|@]|D|@]|E|$I|J]]|$1|V|3|-4|5|6|7|1Y|8|@]|D|@]|E|$]]]|W|$X|$5|Y|Z|10|E|$11|12]]|13|$5|Y|Z|10|E|$11|14]]]]

Use Ruby2Ruby

<pre><code>def save_for_later(&amp;block)
 return nil unless block_given?

 c = Class.new
 c.class_eval do
 define_method :serializable, &amp;block
 end
 s = Ruby2Ruby.translate(c, :serializable)
 s.sub(/^def \S+$([^$]*)\)/, 'lambda { |\1|').sub(/end$/, '}')
end

x = 40
s = save_for_later { |y| x + y }
# =&gt; "lambda { |y|\n (x + y)\n}"
g = eval(s)
# =&gt; #&lt;Proc:0x4037bb2c@(eval):1&gt;
g.call(2) 
# =&gt; 42
</code></pre>

This is great, but it does not close over free variables (like <code>x</code>) and serialize them along with the lambda.

To <a href="https://stackoverflow.com/questions/503583/how-do-you-access-the-symbol-table-in-ruby">serialize variables</a> also, you can iterate over <code>local_variables</code> and serialize them as well. The problem, though, is that <code>local_variables</code> from within <code>save_for_later</code> accesses only <code>c</code> and <code>s</code> in the code above -- i.e. variables local to the serialization code, not the caller. So unfortunately, we must push the grabbing of local variables and their values to the caller.

Maybe this is a good thing, though, because in general, finding all free variables in a piece of Ruby code is <a href="http://en.wikipedia.org/wiki/Undecidable" rel="nofollow noreferrer">undecidable</a>. Plus, ideally we would also save <code>global_variables</code> and any loaded classes and their overridden methods. This seems impractical.

Using this simple approach, you get the following:

<pre><code>def save_for_later(local_vars, &amp;block)
 return nil unless block_given?

 c = Class.new
 c.class_eval do
 define_method :serializable, &amp;block
 end
 s = Ruby2Ruby.translate(c, :serializable)
 locals = local_vars.map { |var,val| "#{var} = #{val.inspect}; " }.join
 s.sub(/^def \S+$([^$]*)\)/, 'lambda { |\1| ' + locals).sub(/end$/, '}')
end

x = 40
s = save_for_later(local_variables.map{ |v| [v,eval(v)] }) { |y| x + y }
# =&gt; "lambda { |y| _ = 40; x = 40;\n (x + y)\n}"

# In a separate run of Ruby, where x is not defined...
g = eval("lambda { |y| _ = 40; x = 40;\n (x + y)\n}")
# =&gt; #&lt;Proc:0xb7cfe9c0@(eval):1&gt;
g.call(2)
# =&gt; 42

# Changing x does not affect it.
x = 7
g.call(3)
# =&gt; 43
</code></pre>

blocks|key|363371|text|使用+|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|363372|这将适用于Ruby+1.8或1.9。|363373|def+save_for_later(&block)
++block.to_source
end

x+=+40
s+=+save_for_later+{%7Cy%7C+x+%2B+y+}
#+=>+"proc+{+%7Cy%7C+(x+%2B+y)+}"
g+=+eval(s)
#+=>+#<Proc:0x00000100e88450@(eval):1>
g.call(2)+
#+=>+42|code-block|syntax|javascript|363374|有关捕获自由变量，请参阅my+other+answer。|363375|sourcify更新：现在您还可以使用serializable_proc+gem，它使用，并捕获局部变量、实例变量、类变量和全局变量。|363376|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/199603/how-do-you-stringize-serialize-ruby-code/199803#199803|1|https://github.com/ngty/serializable_proc^0|0|2|0|0|0|C|F|0|0|18|N|J|H|1|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|13|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|14|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|15|8|@]|D|@$9|16|A|17|1|18]]|E|$]]|$1|O|3|P|5|6|7|19|8|@$9|1A|A|1B|B|C]]|D|@$9|1C|A|1D|1|1E]]|E|$]]|$1|Q|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]|Y|$5|T|U|V|E|$W|Z]]]]

Use <a href="https://github.com/ngty/sourcify" rel="nofollow noreferrer">sourcify</a>

This will work on Ruby 1.8 or 1.9.

<pre><code>def save_for_later(&amp;block)
 block.to_source
end

x = 40
s = save_for_later {|y| x + y }
# =&gt; "proc { |y| (x + y) }"
g = eval(s)
# =&gt; #&lt;Proc:0x00000100e88450@(eval):1&gt;
g.call(2) 
# =&gt; 42
</code></pre>

See <a href="https://stackoverflow.com/questions/199603/how-do-you-stringize-serialize-ruby-code/199803#199803">my other answer</a> for capturing free variables.

Update:
Now you can also use the <a href="https://github.com/ngty/serializable_proc" rel="nofollow noreferrer">serializable_proc</a> gem, which uses sourcify, and captures local, instance, class, and global variables.

I want to be able to write a lambda/Proc in my Ruby code, serialize it so that I can write it to disk, and then execute the lambda later. Sort of like...

<pre><code>x = 40
f = lambda { |y| x + y }
save_for_later(f)
</code></pre>

Later, in a separate run of the Ruby interpreter, I want to be able to say...

<pre><code>f = load_from_before
z = f.call(2)
z.should == 42
</code></pre>

Marshal.dump does not work for Procs. I know Perl has <a href="http://search.cpan.org/~yves/Data-Dump-Streamer-2.08-40/lib/Data/Dump/Streamer.pm" rel="nofollow noreferrer">Data::Dump::Streamer</a>, and in Lisp this is trivial. But is there a way to do it in Ruby? In other words, what would be the implementation of <code>save<code>_</code>for<code>_</code>later</code>?

Edit: <a href="https://stackoverflow.com/questions/199603/how-do-you-stringize-serialize-ruby-code/199803#199803">My answer below</a> is nice, but it does not close over free variables (like <code>x</code>) and serialize them along with the lambda. So in my example ...

<pre><code>x = 40
s = save_for_later { |y| x + y }
# =&gt; "lambda { |y|\n (x + y)\n}"
</code></pre>

... the string output does not include a definition for <code>x</code>. Is there a solution that takes this into account, perhaps by serializing the symbol table? Can you access that in Ruby?

Edit 2: I updated my answer to incorporate serializing local variables. This seems acceptable.

How do you stringize/serialize Ruby code?

解释器

Perl

我希望能够在Ruby代码中编写一个lambda/Proc，序列化它，这样我就可以将它写到磁盘上，然后再执行lambda。有点像..。x = 40f = lambda { |y| x + y }save_for_later(f)稍后，在Ruby解释器的单独运行中，我希望能够说...f = load_from_before...

问如何串行化/序列化Ruby代码？
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