Retrieves global variables of an expression and their associated packages

  envir = parent.frame(),
  tweak = tweakExpression,
  globals = TRUE,
  locals = getOption("future.globals.globalsOf.locals", TRUE),
  resolve = getOption("future.globals.resolve", NULL),
  persistent = FALSE,
  maxSize = getOption("future.globals.maxSize", 500 * 1024^2),



An R expression whose globals should be found.


The environment from which globals should be searched.


(optional) A function that takes an expression and returned a modified one.


(optional) a logical, a character vector, a named list, or a Globals object. If TRUE, globals are identified by code inspection based on expr and tweak searching from environment envir. If FALSE, no globals are used. If a character vector, then globals are identified by lookup based their names globals searching from environment envir. If a named list or a Globals object, the globals are used as is.


Should globals part of any "local" environment of a function be included or not?


If TRUE, any future that is a global variables (or part of one) is resolved and replaced by a "constant" future.


If TRUE, non-existing globals (= identified in expression but not found in memory) are always silently ignored and assumed to be existing in the evaluation environment. If FALSE, non-existing globals are by default ignore, but may also trigger an informative error if option future.globals.onMissing in "error" (should only be used for troubleshooting).


The maximum allowed total size (in bytes) of globals - for the purpose of preventing too large exports / transfers happening by mistake. If the total size of the global objects are greater than this limit, an informative error message is produced. If maxSize = +Inf, then this assertion is skipped. (Default: 500 MiB).


Not used.


A named list with elements expr (the tweaked expression), globals (a named list of class FutureGlobals) and packages (a character string).

See also

Internally, globalsOf() is used to identify globals and associated packages from the expression.