modifyList
Recursively Modify Elements of a List
Description
Recursively modifies elements of list, including the nested list. Elements are identified by their names. 
Usage
modifyList(x, val, keep.null = FALSE)
Arguments
  
| x | a list object to be modified. | 
  | val | a list object that has components to replace the elements in x. | 
  | keep.null | a logical value.  If FALSE (the default), NULL values in val
cause the corresponding element of x to be removed.  If TRUE,
such elements are set to NULL. | 
 
Details
Recursively finds elements in a list. Elements are identified by their names. 
-  If elements of var exist in x, modifyList modifies the existing element.
-  If elements of var do not exist in x, modifyList adds elements to the list x.
Value
returns the modification of the list x with the modified elements that are identified by their names.
See Also
Examples
orig.list <- list(a = 1, b = list(b1 = 2, b2 = TRUE), c = list("iii"))
modifyList(orig.list,
    list(a = 3, b = list(b3 = "new b3", b2 = FALSE), c = FALSE))
modifyList(orig.list,
    list(b = list(b1 = NULL), c = NULL))
modifyList(orig.list,
    list(b = list(b1 = NULL), c = NULL), keep.null = TRUE)