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如何捕捉“=已在命名空间:user中引用:#'clojure.core/=,被clojure中的:#'user/=”替换?

clojure

3

ErtuÄrul Çetin · 技术社区 · 9 年前

eval fn不允许)。问题是,我需要了解用户是否覆盖了一些内置函数,例如 =

有没有办法抓住并阻止这种事情?(想法是他们不应该这样做)

代码:

(defn =
  []
  //some code)

WARNING: = already refers to: #'clojure.core/= in namespace: user, being replaced by: #'user/=

我试图得到警告信息 String 但是 with-out-str 功能不起作用。

(with-out-str
 (defn = [])) 
;=> ""

还写道 with-err-str 不带str 一点点)也不起作用。

(defmacro with-err-str
  [& body]
  `(let [s# (new java.io.StringWriter)]
     (binding [*err* s#]
       ~@body
       (str s#))))

(with-err-str
 (defn = [])) 
;=> ""

"WARNING: = already refers to: #'clojure.core/= in namespace: user, being replaced by: #'user/="

3 回复 | 直到 9 年前

1

2

skrat 9 年前

当你使用 eval :

user=> (with-err-str (eval '(defn - [] 11)))
"WARNING: - already refers to: #'clojure.core/- in namespace: user, being replaced by: #'user/-\n"
user=> (re-seq #"WARNING" (with-err-str (eval '(defn / [] 11))))
("WARNING")

defn 宏,但没有什么阻止他们使用其他clojure工具重新定义变量:

user=> (defmacro defn-safe
  #_=>   [nam & decls]
  #_=>   (if (resolve (symbol "clojure.core" (name nam)))
  #_=>     (print "Whoops")
  #_=>     (list* `defn (with-meta nam (assoc (meta nam) :private true)) decls)))
#'user/defn-safe
user=> (defn-safe foo [x] (+ x 2))
#'user/foo
user=> (foo 22)
24
user=> (defn-safe = [a b] (- a b))
Whoopsnil
user=>

https://github.com/clojure/tools.analyzer

2

Alex Miller 9 年前

clojail 处理这个(以及许多其他事情)。如果你正在寻找沙盒Clojure,我建议你看看。

3

2

ErtuÄrul Çetin 9 年前

(def before (set (vals (ns-map *ns*))))

(defn = [])

(def after (set (vals (ns-map *ns*))))

(clojure.set/difference before after)

;=> #{#'clojure.core/=}