R: Retrieves global variables of an expression and their...

getGlobalsAndPackages {future} | R Documentation

## 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.

[Package future version 1.8.0 Index]