Question

我们怎样才能找出读者宏的作用？

例如，我知道正则表达式#"abc"与(re-pattern "abc")相同。

但是以下内容：(macroexpand #"abc" )会产生#"abc"，那么我怎样才能从读者特殊形式转到＆＃34;正常＆＃34;功能形式？

Answer 1

您可以使用read-string

了解读者扩展到的内容

(read-string "`(rest ~f)")
=>
(clojure.core/seq
 (clojure.core/concat (clojure.core/list (quote clojure.core/rest)) (clojure.core/list f)))
(read-string "#(x %&)")
=> (fn* [& rest__92046#] (x rest__92046#))
(read-string "`(~@x)")
=> (clojure.core/seq (clojure.core/concat x))
(read-string "`(~x)")
=> (clojure.core/seq (clojure.core/concat (clojure.core/list x)))
(read-string "'map")
=> (quote map)
(read-string "#'map")
=> (var map)
(read-string "@x")
=> (clojure.core/deref x)
(binding [*print-meta* true]
  (pr-str (read-string "(def ^:foo x 'map)")))
=> "(def ^{:foo true} x (quote map))"
(read-string "#\"x\"")
=> #"x"

在您的特定情况下：正则表达式以同样的方式打印给您，因为that's how it's printed in clojure。

(class #"abc")
=> java.util.regex.Pattern

Clojure扩展读者宏

1 个答案: