相关疑难解决方法(0)

这段代码

let rec readNLines n list =
 if n = 0 then
  list
 else 
  readNLines(n-1,readInt()::list)

以..结束

Type mismatch. Expecting a 'a but given a 'a -> 'a    
The resulting type would be infinite when unifying ''a' and
''a -> 'a' (using built-in F# compiler)

但是当最后一行改为时运行正常

  readNLines(n-1,(readInt()::list))

要么

  readNLines(n-1)(readInt()::list)

问题是:为什么？:|