Call the value of a mirai, waiting for the the asynchronous operation to resolve if it is still in progress.
call_mirai(aio)a 'mirai' object.
The passed mirai (invisibly). The retrieved value is stored at $data.
This function will wait for the async operation to complete if still in progress (blocking).
A blocking call can be sent a user interrupt with e.g. ctrl+c. If the
ongoing execution in the mirai is interruptible, it will resolve into
an object of class 'miraiInterrupt' and 'errorValue'.
is_mirai_interrupt may be used to handle such cases.
If an error occurs in evaluation, the error message is returned as a
character string of class 'miraiError' and 'errorValue'.
is_mirai_error may be used to test for this.
is_error_value tests for all error conditions including
mirai errors, interrupts, and timeouts.
The mirai updates itself in place, so to access the value of a mirai
x directly, use call_mirai(x)$data.
The value of a mirai may be accessed at any time at $data, and
if yet to resolve, an 'unresolved' logical NA will be returned instead.
Using unresolved on a mirai returns TRUE only if a mirai
has yet to resolve and FALSE otherwise. This is suitable for use in
control flow statements such as while or if.
if (interactive()) {
# Only run examples in interactive R sessions
# using call_mirai()
df1 <- data.frame(a = 1, b = 2)
df2 <- data.frame(a = 3, b = 1)
m <- mirai(as.matrix(rbind(df1, df2)), .args = list(df1, df2), .timeout = 1000)
call_mirai(m)$data
# using unresolved()
m <- mirai({
res <- rnorm(n)
res / rev(res)
},
n = 1e6)
while (unresolved(m)) {
cat("unresolved\n")
Sys.sleep(0.1)
}
str(m$data)
}