Future-class {future} | R Documentation |
A future is an abstraction for a value that may
available at some point in the future. A future can either be
unresolved
or resolved
, a state which can be checked
with resolved()
. As long as it is unresolved, the
value is not available. As soon as it is resolved, the value
is available via value()
.
Future(expr = NULL, envir = parent.frame(), substitute = FALSE, stdout = TRUE, globals = NULL, packages = NULL, seed = NULL, lazy = FALSE, local = TRUE, gc = FALSE, earlySignal = FALSE, label = NULL, ...)
expr |
An R expression. |
envir |
The environment from where global objects should be identified. |
substitute |
If TRUE, argument |
stdout |
If TRUE (default), then the standard output is captured,
and re-outputted when |
globals |
(optional) a logical, a character vector, or a named list
to control how globals are handled.
For details, see section 'Globals used by future expressions'
in the help for |
packages |
(optional) a character vector specifying packages to be attached in the R environment evaluating the future. |
seed |
(optional) A L'Ecuyer-CMRG RNG seed. |
lazy |
If |
local |
If TRUE, the expression is evaluated such that all assignments are done to local temporary environment, otherwise the assignments are done to the global environment of the R process evaluating the future. |
gc |
If TRUE, the garbage collector run (in the process that evaluated the future) after the value of the future is collected. Some types of futures ignore this argument. |
earlySignal |
Specified whether conditions should be signaled as soon as possible or not. |
label |
An optional character string label attached to the future. |
... |
Additional named elements of the future. |
A Future object is itself an environment.
An object of class Future
.
One function that creates a Future is future()
.
It returns a Future that evaluates an R expression in the future.
An alternative approach is to use the %<-%
infix
assignment operator, which creates a future from the
right-hand-side (RHS) R expression and assigns its future value
to a variable as a promise.