Waits for the 'mirai' to resolve if still in progress, and returns its value
directly. It is a more efficient version of and equivalent to
call_mirai(x)$data.
Arguments
- x
a 'mirai' object, or list of 'mirai' objects.
- options
(if
xis a list of mirai) a character vector comprising any combination of collection options formirai_map(), such as".flat"orc(".progress", ".stop").
Value
An object (the return value of the 'mirai'), or a list of such
objects (the same length as x, preserving names).
Details
This function will wait for the asynchronous operation(s) to complete if still in progress, blocking but interruptible.
x[] is an equivalent way to wait for and return the value of a mirai x.
Alternatively
The value of a 'mirai' may be accessed at any time at $data, and if yet to
resolve, an 'unresolved' logical NA will be returned instead.
Using unresolved() on a 'mirai' returns TRUE only if it has yet to resolve
and FALSE otherwise. This is suitable for use in control flow statements such
as while or if.
Errors
If an error occurs in evaluation, the error message is returned as a
character string of class 'miraiError' and 'errorValue'. is_mirai_error()
may be used to test for this. The elements of the original condition are
accessible via $ on the error object. A stack trace comprising a list of
calls is also available at $stack.trace.
If a daemon crashes or terminates unexpectedly during evaluation, an 'errorValue' 19 (Connection reset) is returned.
is_error_value() tests for all error conditions including 'mirai' errors,
interrupts, and timeouts.
Examples
if (FALSE) { # interactive()
# using collect_mirai()
df1 <- data.frame(a = 1, b = 2)
df2 <- data.frame(a = 3, b = 1)
m <- mirai(as.matrix(rbind(df1, df2)), df1 = df1, df2 = df2, .timeout = 1000)
collect_mirai(m)
# using x[]
m[]
# mirai_map with collection options
daemons(1, dispatcher = FALSE)
m <- mirai_map(1:3, rnorm)
collect_mirai(m, c(".flat", ".progress"))
daemons(0)
}