CODEWITHSUNDEEP
rclosures
Davor Josipovic
Davor Josipovic

Reputation: 5504

Serialize closure without environment

I am serializing objects with the serialize function.

For example 

serialize_object <- serialize(some_object, NULL)

Now I have an issue with closures. For example:

closure <- function(){
  member <- NULL
  list(init=function(val){member <<- val})
}
closure_serialized <- serialize(closure(), NULL)

This raw object closure_serialized is huge: some 200MB. I am quite sure that also the environment in which it is made is serialized. But I don't need its environment. I only need the closure and its contents.

Am I doing something wrong? Am I initializing or defining the closure in a wrong way? How can I make it only to serialize the closure and not the rest of the environment? Serializing closures from some packages do not have this effect, and I can not find the culprit.

Upvotes: 2

Views: 262

Answers (1)

Davor Josipovic
Davor Josipovic

Reputation: 5504

This is mainly because the definition of the closure is within a function.

fn <- function(){

    # make big variables

    closure <- function(){
      member <- NULL
      list(init=function(val){member <<- val})
    }

    closure_serialized <- serialize(closure(), NULL)
}

# serialize will copy the environment within the function in closure_serialized
fn()

The serialize function will in that case copy the environment also. A "workaround" is to place the definition of the closure in the global environment.

closure <- function(){
  member <- NULL
  list(init=function(val){member <<- val})
}

fn <- function(){

    # make big variables

    closure_serialized <- serialize(closure(), NULL)
}

# serialize will not copy the global environment.
fn()

The serialize doesn't copy .GlobalEnv environment. See also here for a related topic.

Upvotes: 2

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