module Command

: sig

Async.Command is Core.Command with additional Async functions.

include module type of Core.Std.Command with type t = Core.Std.Command.t and module Spec = Core.Std.Command.Spec

val async : ('a, unit Import.Deferred.t) basic_command

async is like Core.Command.basic, except that the main function it expects returns unit Deferred.t, instead of unit. async will also start the Async scheduler before main is run, and will stop the scheduler when main returns.

val async_basic : ('a, unit Import.Deferred.t) basic_command

async_basic is a deprecated synonym for async that will eventually go away. It is here to give code outside jane street a chance to switch over before we delete it.

val async_or_error : ('a, unit Import.Deferred.Or_error.t) basic_command

async_or_error is like async, except that the main function it expects may return an error, in which case it prints out the error message and shuts down with exit code 1.

To create an Arg_type.t that uses auto-completion and uses Async to compute the possible completions, one should use

      Arg_type.create ~complete of_string

where complete wraps its Async operations in Thread_safe.block_on_async. With this, the complete function is only called when the executable is auto-completing, not for ordinary execution. This improves performance, and also means that the Async scheduler isn't started for ordinary execution of the command, which makes it possible for the command to daemonize (which requires the scheduler to not have been started).

end