调用适用于defrecord构造函数？

Question

core=> (defrecord Puffball [id name]) 
core.Puffball 
core=> (Puffball. 149 "Urist") 
#core.Puffball{:id 149, :name "Urist"} 
core=> (apply Puffball. [149 "Urist"]) 
CompilerException java.lang.RuntimeException: java.lang.ClassNotFoundException: Puffball., compiling:(NO_SOURCE_PATH:3) 
core=> (apply Puffball [149 "Urist"]) 
ClassCastException java.lang.Class cannot be cast to clojure.lang.IFn clojure.core/apply (core.clj:600) 

如何从矢量创建马勃球？

Answer 1

在Clojure中1.3记录定义自动地引入工厂功能：

Clojure 1.3.0 
user=> (defrecord Puffball [id name]) 
user.Puffball 
user=> (apply ->Puffball [149 "Urist"]) 
#user.Puffball{:id 149, :name "Urist"} 

->Puffball是 “位置” 工​​厂功能;也有map->Puffball这是顾名思义。

Answer 2

对于那些不上的1.3.x（或需要的记录以外这样的功能），下面模拟apply用java方法和构造：

 
(defmacro applyj 
    ([mc args] `(~mc ~@args)) 
    ([mc x args] `(~mc ~x ~@args)) 
    ([mc x y args] `(~mc ~x ~y ~@args)) 
    ([mc x y z args] `(~mc ~x ~y ~z ~@args))) 

 
user=> (defrecord Puffball [id name]) 
user.Puffball 
user=> (applyj Puffball. [149 "Urist"]) 
#:user.Puffball{:id 149, :name "Urist"}