List Storage Generator

This is a function that will generate an object that can serve as persistant storage for pre-computed values. Each object contains a list called .this_list embedded within the enviroment it was created in.

Usage

.list_store()

Value

a list with five functions the all operate on the internal .this_list list object:

• get() returns the value of .this_list

• update(value) updates .this_list with a modified list value. Useful for adding several pieces of information at once.

• set(key, value) sets a given key (vector, with each element representing a level of nesting) to a particular value (can be a vector or list). If the key is NULL, .this_list is replaced with value

• clear() sets .this_list to NULL

• copy() creates an independent copy of the object for modification.

Examples

if (FALSE) {
  # note: asNamespace() gives access to internal functions. This is for
  # demonstration purposes only. There is no guarantee for these functions to
  # work.
  global_list <- asNamespace("sandpaper")$.list_store()
  global_list$set(key = NULL, list(a = 1, b = list(2)))
  global_list$set(key = "c", "three")
  global_list$get()
  global_list$update(list(c = "THREE", d = global_list$get()))
  global_list$get()
}