[R] signalCondition

[Hadley Wickham]

Does signalCondition() only work within try-catch blocks?

I expected:

testSignal <- function() {
    error <- simpleError("An error!")
    signalCondition(error)
}

to do the same thing as

testStop <- function() {
    error <- simpleError("An error!")
    stop(error)
}

but testSignal returns NULL without throwing an error.  Have I 
misunderstood something?

Thanks,

Hadley