Identifiers

MaLo-ID, MeLo-ID, BDEW-Codenummer, EIC and OBIS as types: parsed at the boundary, check characters verified, one canonical string each.

Each identifier is a type that verifies what its scheme defines at the parse. Parse at the boundary.

MaLo-ID

The check digit is the Lok- und Waggon-Kennzeichnungsverfahren: the sum of the odd positions plus twice the sum of the even positions (not Luhn), to the next multiple of ten. It misses a ±5 change in an even position and a transposition of two digits five apart.

use metering::MaloId;

// The worked example of the BDEW Anwendungshilfe.
let malo: MaloId = "41373559241".parse().unwrap();
assert_eq!(malo.check_digit(), 1);

// A transposed pair no longer matches its check digit.
assert!("41373559214".parse::<MaloId>().is_err());

MeLo-ID

The MeLo-ID is the Zählpunktbezeichnung: country code, six-digit Netzbetreiber number, five characters of Postleitzahl, twenty assigned by the Netzbetreiber.

use metering::MeloId;

let melo: MeloId = "DE00056266802AO6G56M11SN51G21M24S".parse().unwrap();
assert_eq!(melo.country(), "DE");
assert_eq!(melo.netzbetreiber_nr(), "000562");
assert!("not a zaehlpunkt".parse::<MeloId>().is_err());

BDEW-Codenummer

The thirteenth digit follows the MaLo procedure except for a GS1 GLN, which carries GS1's own. The type accepts a code that passes either and reports which (issuer, has_bdew_check_digit).

use metering::ids::{BdewCode, Issuer};

let check = BdewCode::compute_check_digit("990098765432").unwrap();
let nb: BdewCode = format!("990098765432{check}").parse().unwrap();
assert_eq!(nb.issuer(), Issuer::Bdew);

let gln: BdewCode = "4012345000009".parse().unwrap();
assert_eq!(gln.issuer(), Issuer::Gs1);

assert!("9900987654321".parse::<BdewCode>().is_err()); // fails both

EIC

Addresses Bilanzkreise, Bilanzierungsgebiete and Regelzonen; the check character is enforced. A German Bilanzierungsgebiet names its Regelzone in position 4 (Eic::regelzone).

use metering::ids::{Eic, EicType, Regelzone};

let regelzone: Eic = "10YDE-VE-------2".parse().unwrap();
assert_eq!(regelzone.object_type(), Some(EicType::Area));
assert!("10YED-VE-------2".parse::<Eic>().is_err()); // transposed pair

assert_eq!(Regelzone::Amprion.control_area_eic().to_string(), "10YDE-RWENET---I");
assert_eq!(Eic::compute_check_character("10X---ENTSOE---"), Some('L'));

OBIS codes

A-B:C.D.E: A the medium, C the quantity and direction (1 Bezug, 2 Lieferung), D the Messart (8 Zählerstand, 29 Lastgang, 6 Maximum), E the tariff (63 is the Fehlerregister). Kind, unit, tariff and default grid derive from one reading of the code.

use metering::{Direction, ObisCode, Resolution, Unit};

let bezug: ObisCode = "1-0:1.8.0*255".parse().unwrap();
assert_eq!(bezug.to_string(), "1-0:1.8.0"); // one canonical string
assert_eq!(bezug.direction(), Some(Direction::Import));
assert_eq!(bezug.unit(), Some(Unit::KiloWattHour));
assert_eq!(bezug.as_lastgang(), Some(ObisCode::STROM_BEZUG_LASTGANG));

// A Brennwert's E names the averaging period, not a tariff.
assert_eq!(ObisCode::GAS_BRENNWERT_MONATSMITTEL.tariff(), None);
assert_eq!(ObisCode::GAS_BRENNWERT_MONATSMITTEL.default_resolution(), Some(Resolution::Month));

Display writes the reduced form — Codeliste § 2.3: "Wertegruppe F wird für die Kommunikation im deutschen Gasmarkt nicht verwendet". {:#} writes all six groups; parsing accepts both, leading zeros and surrounding whitespace. Key storage on the displayed form.