gl_gtin/gtin_types

Shared public GTIN types.

This module defines the public GtinError and GtinFormat types in a location that does NOT import the root gl_gtin facade. Both the facade (gl_gtin) and the sub-modules that already work in GtinError (e.g. gl_gtin/upc) import these types from here, which breaks what would otherwise be an import cycle (gl_gtin → gl_gtin/upc → gl_gtin).

The root gl_gtin module re-exports these types via type aliases (gl_gtin.GtinError, gl_gtin.GtinFormat) so the public type names are unchanged. The variant constructors are owned by this module, so consumers import them from here, e.g. import gl_gtin/gtin_types.{Gtin13, InvalidFormat}.

Types

GtinError

</>

Errors that can occur when working with GTIN codes.

pub type GtinError {
  InvalidLength(got: Int)
  InvalidCheckDigit
  InvalidCharacters
  NoGs1PrefixFound
  InvalidFormat
  InvalidKeyFormat
}

Constructors

```
InvalidLength(got: Int)
```
Input has wrong number of digits. Includes the actual length provided.
```
InvalidCheckDigit
```
Check digit does not match the calculated value.
```
InvalidCharacters
```
Input contains non-numeric characters.
```
NoGs1PrefixFound
```
GS1 prefix not found in the database.
```
InvalidFormat
```
Operation not applicable to this GTIN format.
```
InvalidKeyFormat
```
Key-specific structural failure: a GS1 key (e.g. a variable-serial Grai/Giai) whose length and check digit are plausible but whose component structure is malformed. Distinct from InvalidFormat, which remains reserved for GTIN format-conversion failures.

GtinFormat

</>

Supported GTIN formats based on digit count.

pub type GtinFormat {
  Gtin8
  Gtin12
  Gtin13
  Gtin14
}

Constructors

```
Gtin8
```
8-digit GTIN format, used for small packages outside North America
```
Gtin12
```
12-digit GTIN format (UPC-A), primarily used in North America
```
Gtin13
```
13-digit GTIN format (EAN-13), used internationally
```
Gtin14
```
14-digit GTIN format (ITF-14), used for trade items at various packaging levels