Struct ServiceStringAdvice 

pub struct ServiceStringAdvice {
    pub element_sep: u8,
    pub component_sep: u8,
    pub release_char: u8,
    pub decimal_mark: u8,
    pub repetition_sep: u8,
    pub segment_term: u8,
}

EDIFACT service string advice (UNA segment).

Defaults: + (element), : (component), ? (release), . (decimal mark), * (repetition separator), ' (segment terminator).

All six service characters are now first-class fields. is_valid() checks all six for mutual distinctness and printability so that a collision between the repetition separator and any other delimiter is caught at UNA parse time.

Fields

element_sep: u8

Data element separator (default +)

component_sep: u8

Component data element separator (default :)

release_char: u8

Release character (default ?)

decimal_mark: u8

Decimal notation mark (default .; UNA byte 5, ISO 9735-1 §7.1). Not used by the tokenizer for splitting, but preserved for downstream use.

repetition_sep: u8

Repetition separator (default *; UNA byte 7, ISO 9735-4 §3.1).

Some DVGW gas-market profiles and other non-default EDIFACT implementations use a non-standard repetition separator. This field is always populated from the UNA (or defaults to b'*' when no UNA is present) so that downstream code can access it without re-parsing the raw UNA bytes.

The tokenizer does not currently split on the repetition separator — that responsibility belongs to downstream consumers — but is_valid() includes it in the six-way uniqueness check to catch delimiter collisions early.

segment_term: u8

Segment terminator (default ')

Implementations

impl ServiceStringAdvice

pub fn from_bytes(input: &[u8]) -> Result<Self, EdifactError>

Parse a UNA header and validate that all six service characters (element_sep, component_sep, decimal_mark, release_char, repetition_sep, and segment_term) are mutually distinct and in the printable ASCII range 0x21–0x7E.

Returns EdifactError::InvalidUna if the invariant is violated. Falls back to ServiceStringAdvice::default when no UNA is present.

This is the safe, default constructor — always use this for input from an external source. For trusted or internal use where delimiter uniqueness is already guaranteed, use from_bytes_unchecked.

pub fn from_bytes_unchecked(input: &[u8]) -> Self

Parse a UNA header from the beginning of an EDIFACT interchange without validating delimiter uniqueness or printability.

If no UNA is present, returns ServiceStringAdvice::default.

The repetition_sep field is populated from UNA byte 7 (ISO 9735-4 §3.1) or defaults to b'*' when no UNA is present.

When to use

Use this only for trusted internal data (e.g. round-tripping data where the UNA invariant is already guaranteed) or in fuzz/property tests that intentionally explore degenerate delimiter combinations.

For any external or user-provided input, prefer from_bytes which validates delimiter uniqueness and rejects invalid bytes.

pub fn is_valid(&self) -> bool

Return true if all active service characters are mutually distinct and printable ASCII.

The five mandatory characters (element_sep, component_sep, decimal_mark, release_char, segment_term) must all be in the printable ASCII range 0x21–0x7E and mutually distinct (10 pairwise checks).

The repetition_sep field is also validated when it is not a space (0x20). A space at position 7 of the UNA is the conventional “absent” sentinel used by interchanges that do not employ repetition elements (ISO 9735-1 / ISO 9735-4 §3.1), and it is accepted without a printability or uniqueness check. Any other value must be printable ASCII and distinct from the five mandatory characters and from the configured repetition separator value.

Bytes outside 0x21–0x7E (for mandatory chars) or a non-space value outside that range (for repetition_sep) are rejected because high-bytes (>= 0x80) would incorrectly bisect multi-byte UTF-8 sequences, and DEL (0x7F) is a non-printable control character.

Trait Implementations

impl Clone for ServiceStringAdvice

fn clone(&self) -> ServiceStringAdvice

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ServiceStringAdvice

impl Debug for ServiceStringAdvice

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ServiceStringAdvice

fn default() -> Self

Returns the “default value” for a type.

impl Eq for ServiceStringAdvice

impl PartialEq for ServiceStringAdvice

fn eq(&self, other: &ServiceStringAdvice) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ServiceStringAdvice