Create a sequential controller.

The sequential controller runs tasks on the same R process where the controller object exists. Tasks run sequentially rather than in parallel.

Usage

crew_controller_sequential(
  reset_globals = TRUE,
  reset_packages = FALSE,
  reset_options = FALSE,
  garbage_collection = FALSE
)

Arguments

reset_globals

TRUE to reset global environment variables between tasks, FALSE to leave them alone.

reset_packages

TRUE to detach any packages loaded during a task (runs between each task), FALSE to leave packages alone. In either case, the namespaces are not detached.

reset_options

TRUE to reset global options to their original state between each task, FALSE otherwise. It is recommended to only set reset_options = TRUE if reset_packages is also TRUE because packages sometimes rely on options they set at loading time. for this and other reasons, reset_options only resets options that were nonempty at the beginning of the task. If your task sets an entirely new option not already in options(), then reset_options = TRUE does not delete the option.

garbage_collection

TRUE to run garbage collection after each task task, FALSE to skip.

See also

Other sequential controllers: crew_class_controller_sequential

Examples

if (identical(Sys.getenv("CREW_EXAMPLES"), "true")) {
controller <- crew_controller_sequential()
controller$push(name = "task", command = sqrt(4))
controller$pop()
}