Creates a count operator, which counts the number of emissions on the source and emits that number when the source completes.
Stream of type
using Rocket source = from([ i for i in 1:42 ]) subscribe!(source |> count(), logger()) ; # output [LogActor] Data: 42 [LogActor] Completed
count transforms an Observable that emits values into an Observable that emits a single value that represents the number of values emitted by the source Observable. If the source Observable terminates with an error, count will pass this error notification along without emitting a value first. If the source Observable does not terminate at all, count will neither emit a value nor terminate.
Counts how many values source Observable have emitted before the complete event happened
using Rocket source = from([ i for i in 1:42 ]) subscribe!(source |> count(), logger()) # output [LogActor] Data: 42 [LogActor] Completed