[R language study notes] - modify global variables to produce their own package of

edit global variable in my package

Scenes

Recently I'd had a package R language, mainly encapsulated some of the performance function. These features have been added to the back, a bit like framework called. This involves the problem of global variables within the package. I assume that the package name mypackage, I want to implement a number of incremental acquisition function.
Code 1

COUNT <- 1
get_sn <- function(){
	COUNT <- COUNT + 1
	return(COUNT)
}

Called multiple times mypackage::get_sn(), the results were 2, this should not be construed COUNT reason as global variables.

Code 2

COUNT <- 1
get_sn <- function(){
	COUNT <<- COUNT + 1
	return(COUNT)
}

Call mypackage::get_sn()error. The error was Error in COUNT <<- COUNT + 1 : 无法改变被锁定的联编'COUNT'的值.
I understand COUNT became defined const, it is read onlythe.
The attempt by directly modifying, mypackage::COUNT <- 100is not enough, the error is Error in mypackage::COUNT <- 1 : 找不到对象'mypackage'. Here I can only read but not write to understand, with other languages namespaceon using still some gaps.

solution

Variables can be explicitly modified by the environment.
Code 3

myenv <- new.env()
myenv$COUNT <- 1

get_sn <- function(){
  myenv$COUNT <- myenv$COUNT + 1
  return(myenv$COUNT)
}

Multiple calls mypackage::get_sn()can get incremental figures.
Here we should note in particular, mypackage::myenv$COUNT <- 100direct modifications are being given, find the object.