We provide a type t deconstructing this string into its components. Functions to_string and of_string print and parse strings according to the AWS specification.
Additionally, we provide functions for constructing ARNs specific to a service, e.g. s3. These are more convenient because certain services don't require or disallow certain components of a general ARN, so these functions ask for only what is needed. Also, ARNs may have additional requirements for a given service, which these functions may enforce (though we don't yet).