matter_codec/
tag.rs

1//! Matter TLV tag forms.
2//!
3//! All five tag forms from the Matter Core Specification §A.2 are
4//! represented here. The wire format has separate 2-byte / 4-byte
5//! sub-variants for `CommonProfile`/`ImplicitProfile` and 6-byte /
6//! 8-byte sub-variants for `FullyQualified`; the public enum collapses
7//! those under a single variant per form, and the writer picks the
8//! minimum-width sub-variant from the value.
9
10/// A Matter TLV tag.
11///
12/// The enum is marked `#[non_exhaustive]` so adding hypothetical future
13/// variants is not a breaking change for downstream `match` expressions.
14#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
15#[non_exhaustive]
16pub enum Tag {
17    /// No tag bytes follow the control octet.
18    Anonymous,
19
20    /// One tag byte follows, carrying the context-specific tag number.
21    Context(u8),
22
23    /// A common-profile tag number. The writer emits 2 bytes if the value
24    /// fits in `u16`, otherwise 4 bytes.
25    CommonProfile(u32),
26
27    /// An implicit-profile tag number. The writer emits 2 bytes if the
28    /// value fits in `u16`, otherwise 4 bytes.
29    ImplicitProfile(u32),
30
31    /// A fully-qualified tag. Vendor and profile are always 2 bytes each
32    /// on the wire; the writer emits 2 bytes for `tag` if it fits in
33    /// `u16`, otherwise 4 bytes.
34    FullyQualified {
35        /// 16-bit vendor identifier.
36        vendor: u16,
37        /// 16-bit profile identifier within the vendor.
38        profile: u16,
39        /// Tag number within the profile.
40        tag: u32,
41    },
42}
matter_codec/tag.rs

matter_codec/
tag.rs
