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如何从地图填充Clojure记录？

[英]How to populate a Clojure record from a map?

原文 2012-05-25 18:01:15 5 1 data-structures/ clojure/ record

Is there something like struct-map for records? 是否有类似struct-map的记录？ If not, should I use a struct (the docs discourage use of structs)? 如果没有，我是否应该使用结构（文档不鼓励使用结构）？

Maybe I am doing the wrong thing completely? 也许我完全在做错事？ I have a rather complex function which currently takes a map of options. 我有一个相当复杂的功能，目前带有选项图。 I am trying to clarify what option values are acceptable/used (by replacing it with a record). 我试图弄清楚哪些选项值可以接受/使用（通过将其替换为记录）。 And now I want to interface that to code that has this information in maps (and which contain a superset of the data in the record). 现在，我想将其与映射中具有此信息的代码进行接口（并且在记录中包含数据的超集）。

1 个解决方案

It's not recommended to use records simply for "documentation" - plain old maps are more flexible, simpler, and easier. 不建议仅将记录用于“文档”-普通的旧地图更灵活，更简单，更容易。 For documentation, you can merely add a docstring, or a comment, or create a function like (defn make-whatever [thing1 thing2]) . 对于文档，您仅可以添加文档字符串或注释，或创建类似(defn make-whatever [thing1 thing2])的函数。

If you still want a record, you have a couple choices depending on whether you're using clojure version 1.3 or higher. 如果仍然需要记录，则可以选择两种方式，具体取决于您使用的是Clojure 1.3版还是更高版本。 If so, (defrecord Whatever ...) also defines a map->Whatever function, and a ->Whatever function that takes positional args. 如果是这样，则(defrecord Whatever ...)还定义了map->Whatever函数，以及一个带有位置参数的->Whatever函数。 If not, you can write (into (Whatever. nil nil nil) some-map) (passing the right number of nils for the record type). 如果没有，则可以写入(into (Whatever. nil nil nil) some-map) 。nil (into (Whatever. nil nil nil) some-map) （为记录类型传递正确数量的nil）。