future (version 1.3.0)

getGlobalsAndPackages: Retrieves global variables of an expression and their associated packages

Description

Retrieves global variables of an expression and their associated packages

Usage

getGlobalsAndPackages(expr, envir = parent.frame(), tweak = tweakExpression,
  globals = TRUE, resolve = getOption("future.globals.resolve", FALSE),
  persistent = FALSE, ...)

Arguments

expr

An R expression whose globals should be found.

envir

The environment from which globals should be searched.

tweak

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

globals

(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.

resolve

If TRUE, any future that is a global variables (or part of one) is resolved and replaced by a "constant" future. persistent 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 ignored, but may also trigger an informative error if option future.globals.onMissing == "error".

…

Not used.

Value

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

See Also

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