OS.Env
type t = string Astring.String.map
val current : unit -> (t, [> Rresult.R.msg ]) result
val set_var : string -> string option -> (unit, [> Rresult.R.msg ]) result
val req_var : string -> (string, [> Rresult.R.msg ]) result
type !'a parser = string -> ('a, Rresult.R.msg) result
val parser : string -> (string -> 'a option) -> 'a parser
val bool : bool parser
val string : string parser
val parse : string -> 'a parser -> absent:'a -> ('a, [> Rresult.R.msg ]) result
val value : ?log:Logs.level -> string -> 'a parser -> absent:'a -> 'a