When using value() internally for collection the results, use stdout …

…= FALSE to avoid spurious outputs. When all backends moved to implementing result(), we'll use that instead of value()

R/ClusterFuture-class.R

@@ -239,7 +239,7 @@ resolved.ClusterFuture <- function(x, timeout = 0.2, ...) {
   } else {
     ## stop("Not yet implemented: ", paste(sQuote(class(node)), collapse = ", "))
     warning(sprintf("resolved() is not yet implemented for workers of class %s. Will use value() instead and return TRUE", sQuote(class(node)[1])))
-    value(x, signal = FALSE)
+    value(x, stdout = FALSE, signal = FALSE)
     res <- TRUE
   }
 

R/Future-class.R

@@ -313,7 +313,7 @@ result.Future <- function(future, ...) {
     ## BACKWARD COMPATIBILITY:
     ## For now, it is value() that collects the results.  Later we want
     ## all future backends to use result() to do it. /HB 2018-02-22
-    value(future, signal = FALSE)
+    value(future, stdout = FALSE, signal = FALSE)
   }
 
   result <- future$result

R/FutureRegistry.R

@@ -23,7 +23,7 @@ FutureRegistry <- local({
         ##     This, this may result in a call to
         ##     FutureRegistry(..., action = "remove").
         tryCatch({
-          value(future, signal = FALSE)
+          value(future, stdout = FALSE, signal = FALSE)
         }, FutureError = function(ex) {
           mdebug(sprintf("Detected a %s while FutureRegistry collecting results: %s",
                  class(ex)[1], paste(capture.output(print(ex)), collapse = "\n")))

R/stdout_OP.R

@@ -7,6 +7,8 @@
 #' @param fassignment The future assignment, e.g.
 #'        \code{x \%<-\% \{ expr \}}.
 #'
+#' @param capture If TRUE, the standard output will be captured, otherwise not.
+#'
 #' @export
 `%stdout%` <- function(fassignment, capture) {
   fassignment <- substitute(fassignment)