sig
type path_elem = [ `Field of string | `Index of int ]
type path = Ag_util.Validation.path_elem list
val string_of_path : Ag_util.Validation.path -> string
type error = {
error_path : Ag_util.Validation.path;
error_msg : string option;
}
val error :
?msg:string -> Ag_util.Validation.path -> Ag_util.Validation.error
val string_of_error : Ag_util.Validation.error -> string
end