Struct ComponentRef 

pub struct ComponentRef { /* private fields */ }

Reference to a component data element within a composite data element.

Composites such as C507 (DTM date/time/period) are addressed by the identifier of their own components (2005, 2380, 2379), which is what makes code-addressed access — Segment::value_by_code and #[edifact(element = "2005")] — resolve to the right slot instead of a hand-counted index.

Fields are private to enforce the one-based position invariant.

Implementations

impl ComponentRef

pub const fn new( position: u8, data_element: &'static str, status: Status, ) -> Self

Construct a ComponentRef with compile-time position validation.

position must be ≥ 1 (one-based). In a const context a zero position is a compile-time error; at runtime it panics.

Panics

Panics if position == 0.

Example

use edifact_rs::{ComponentRef, Status};

const DTM_2005: ComponentRef = ComponentRef::new(1, "2005", Status::Mandatory);

pub const fn repeated( position: u8, data_element: &'static str, status: Status, repeat_count: u8, ) -> Self

Declare a component the composite repeats by design.

Several standard composites carry the same data element several times over: C080 PARTY NAME is 3036 five times followed by 3045, C059 STREET is 3042 four times. Spelling that out as five separate new entries made the code count as five positions, so resolve_code reported it ambiguous and the component could not be code-addressed at all — a faithful declaration was punished, and the only way to use named access was to declare the composite incompletely and disagree with the directory it claims to model.

One repeated entry is one position, so 3036 resolves to occurrence 1 — what “the party name” means in every real message — while the definition still records that five slots belong to it.

position is the first slot; the next component follows at position + repeat_count.

Panics

Panics if position == 0 or repeat_count == 0.

Example

use edifact_rs::{ComponentRef, ElementRef, SegmentDefinition, SegmentLayout, Status};

// C080 PARTY NAME: 3036 ×5, then 3045 at position 6.
static C080: &[ComponentRef] = &[
    ComponentRef::repeated(1, "3036", Status::Mandatory, 5),
    ComponentRef::new(6, "3045", Status::Conditional),
];
static NAD_ELEMENTS: &[ElementRef] = &[
    ElementRef::new(1, "3035", Status::Mandatory, 1),
    ElementRef::composite(4, "C080", Status::Conditional, 1, C080),
];
static NAD: SegmentDefinition = SegmentDefinition::new("NAD", "Name and address", NAD_ELEMENTS);

// Addressable, and it points at the first occurrence.
let path = NAD.resolve_code("3036")?;
assert_eq!((path.element, path.component), (3, Some(0)));

pub const fn repeat_count(&self) -> u8

How many consecutive slots this component occupies.

1 for a component declared with new.

pub const fn position(&self) -> u8

One-based component position within the composite.

pub const fn data_element(&self) -> &'static str

UN/EDIFACT component data element identifier.

pub const fn status(&self) -> Status

Requirement status of the component.

pub const fn with_repr(self, repr: Repr) -> Self

Attach the directory’s representation, e.g. an..35.

Without one, a definition still resolves identifiers and checks presence; with one, DirectoryValidator also checks length and character class — which is what a partner’s translator does before it rejects the file.

Example

use edifact_rs::{ComponentRef, Repr, Status};

const SENDER: ComponentRef =
    ComponentRef::new(1, "0004", Status::Mandatory).with_repr(Repr::an_up_to(35));

pub const fn repr(&self) -> Option<Repr>

The declared representation, if the definition states one.

pub const fn with_repr_by_syntax_version( self, up_to_v3: Repr, from_v4: Repr, ) -> Self

Declare a representation that changed between syntax versions.

The service directory has exactly one such position: S004 DE 0017, the date of preparation. Version 3 transfers YYMMDD (n6); version 4 widened it to CCYYMMDD (n8) to be year-2000 correct. It is the only place where version 4 is not a superset of version 3.

Declaring both keeps each version checked exactly. Collapsing them into n..8 would have accepted a six-digit date in a version 4 interchange and a seven-digit one in either — validating neither version correctly.

The syntax version comes from UNB S001 DE 0002. When it cannot be determined — validating a bare message window, say — both are accepted, because guessing would reject conformant data.

pub const fn repr_from_v4(&self) -> Option<Repr>

The representation used from syntax version 4 onward, when it differs.

Trait Implementations

impl Clone for ComponentRef

fn clone(&self) -> ComponentRef

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ComponentRef

impl Debug for ComponentRef

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

Formats the value using the given formatter.