设置，让，宏，螺母 [英] set, let, macros, nuts

问题描述

我正在尝试从html内容构建快速目录. (简而言之)

I am trying to build a quick toc from an html content. (to make it short)

代码简直太简单了:

(defn toc [content]
 (doseq [i (take 5 (iterate inc 1))] 
   (let [h  (str "h" i)]
    (println ($ content h)))))

其中 content 是html内容， $ 是 clojure-soup

where content is the html content, and $ is a macro required from clojure-soup

而

($ content "h1")

起作用，并返回所有标签的列表.

works, and returns a list of all the tags.

简单:

($ content (str "h" 1))

我不会做任何事情.

我如何强制

(str "h" 1) 

要在之前正确评估 宏被称为?

奖励原因:)

推荐答案

如果您暗示$是宏，则这是不可能的:这根本不是宏的工作方式.宏需要在编译时扩展为某种东西，并且只能扩展一次.您具有运行时数据，例如h的各种值，但是无法在编译时使用它.对我来说，听起来$应该是一个函数.

This is not possible if, as you imply, $ is a macro: it's simply not how macros work. The macro needs to expand into something, at compile time, and it can only do so once. You have run-time data, like the various values of h, but there is no way to use that at compile-time. To me it sounds like $ should have been a function.

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