如何处理Clojurescript宏中所需的Clojurescript代码? [英] How do I deal with required Clojurescript code from Clojurescript macros?

问题描述

让我们说我有一个X.clojurescript和一个X.clojure命名空间.X.clojurescript中的所有内容都是Clojurescript代码，X.clojure中的所有内容都是Clojure代码.不幸的是，我不能直接在Clojurescript中定义宏，我必须在Clojure中定义它们，然后使用

Let us say I have a X.clojurescript and a X.clojure namespace. Everything in X.clojurescript is Clojurescript code, everything in X.clojure is Clojure code. Unfortunately, I cannot define macros directly in Clojurescript, I have to define them in Clojure and then bring them into a Clojurescript namespace using

(ns X.clojurescript.abc
  (:require-macros [X.clojure.def :as clj]))

这很好.但是，如果宏(在X.clojurere中定义)需要引用在Clojurescript命名空间(X.clojurescript)中定义的内容，该怎么办?问题在于，在解决其他命名空间时，Clojure编译器不会在我的Clojurescript命名空间(单独的目录)中查找.

This is fine. However, what if the macro (defined in X.clojure) is going to need to reference something defined in a Clojurescript namespace (X.clojurescript)? The problem is that the Clojure compiler does not look in my Clojurescript namespace (a separate directory) when resolving other namespaces.

我已经通过在Clojure代码中简单创建一个名称空间来解决这个问题，该名称空间具有与Clojurescript中存在的名称空间和所需的定义相同的名称，但这似乎有点愚蠢.因此，例如，如果我在宏中需要X.clojurescript.abc.y，我将仅在Clojure端创建一个额外的命名空间，以在我的X.clojurescript.abc的Clojure版本中定义一个虚拟y.有点愚蠢.

I have gotten around this problem by simply creating a namespace in my Clojure code that has the same namespace and needed definition as exist in Clojurescript, but this seems kind of stupid. So, for instance, if I need X.clojurescript.abc.y in my macro, I will just create an additional namespace on the Clojure side that defs a dummy y in my Clojure version of X.clojurescript.abc; kind of dumb.

我该如何处理需要引用Clojurescript方面的宏?

How do I deal with a macro that needs to refer to something on the Clojurescript side?

推荐答案

宏在定义时唯一需要特定命名空间的时间是，如果宏正在使用来自该命名空间的代码来生成符号列表，它将返回

The only time a macro needs a specific namespace at the time of definition is if the macro is using code from said namespace to generate the list of symbols it will return.

您可以在repl中遵循以下示例:

you can follow along with these examples in the repl:

(defmacro foo
  [a]
  `(bar/bar ~a))

即使bar不是定义的名称空间，foo的定义也会编译

the definition of foo will compile even though bar is not a defined namespace

(foo :a)

调用foo现在将失败，因为您尚未定义bar名称空间或功能bar

calling foo will now fail because you have not defined the bar namespace, or the function bar yet

(ns bar)
(defn bar
  [x]
  [x x])

在bar名称空间中定义bar

defines bar in the bar namespace

(ns user)
(foo :a)

=> [:a:a]

=> [:a :a]

请注意，在foo定义时，bar不需要存在.实际上，在定义foo时，甚至不需要存在名称空间.

Notice that bar does not need to exist at the time of foo's definition. In fact the namespace does not even need to exist at the time of foo's definition.

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