Clojure：如何将clojure代码转换为可评估的字符串？它大多是工作，但列表被翻译为原始的括号，失败 [英] Clojure: How do I turn clojure code into a string that is evaluatable? It mostly works but lists are translated to raw parens, which fails

问题描述

我有一个这样的简单结构：

 （def example {：bbbbbb：xxx [1 2 3 ]：yyy'（3 5 7）}）
  

如果我把它写入文件，

  {：bbbbbb：xxx [1 2 3]：yyy（3 5 7）} 
  

这是大多数正确的，但如果我加载文件对此，它失败，因为它试图把3作为一个函数括号不再被引用，因此尝试作为一个函数求值）。

这样做的正确方法是什么？谢谢！

解决方案

如果要读回以前写为文件的Clojure数据， code>读取或读取字符串，而不是 load-file ：

 （with-open [fd（java.io.PushbackReader。
（io / reader路径/到/文件）））] 
（读取fd））
  

调用多次读取以读取连续的表单（只要您持有 Reader 打开） p>



这不涉及任何评估，除非在输入流中出现＃= 读取器宏，在这种情况下，它在读取时被评估并且被替换为读取的输出（例如（读字符串＃=（+ 1 2）） ）返回 3 ）。禁止评估＃= 前缀表单bind * read-eval * 到 false 。

I have a simple structure like this:

(def example {:bbb "bbb" :xxx [1 2 3] :yyy '(3 5 7)})

If I write this out to a file it contains

{:bbb "bbb" :xxx [1 2 3] :yyy (3 5 7)}

Which is mostly correct, but if I load-file on this, it fails because it tries to treat 3 as a function (the parens are no longer quoted, so tries to evaluate as a function).

What is the right way to do this? Thanks!

解决方案

If you want to read back a Clojure datum previously written to a file as a literal, you need to use read or read-string rather than load-file:

(with-open [fd (java.io.PushbackReader.
                (io/reader (io/file "/path/to/file")))]
  (read fd))

You can call read multiple times to read successive forms (as long as you hold the Reader open, of course).

This involves no evaluation except when the #= reader macro occurs in the input stream, in which case the form immediately following it is evaluated at read time and replaced with the result in read's output (e.g. (read-string "#=(+ 1 2)") returns 3). To prohibit evaluation of #= prefixed forms bind *read-eval* to false.

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