Struct Username 

pub struct Username { /* private fields */ }

A normalized username claim: NFC, lowercase, bounded, never address-shaped.

Construct with Username::from_str. The stored form is the normalized form, so Username::as_str is what gets hashed into a discovery tag, signed into a record, and compared against a queried name.

Ordering

Ord compares the normalized bytes. Nothing in the protocol breaks a tie on usernames — a resolution returns an unordered set of claims and the user arbitrates — so this exists for deterministic test fixtures and BTreeMap keys, not for consensus.

Implementations

impl Username

pub const MAX_BYTES: usize = 64

Maximum length of the normalized form, in bytes.

Bytes rather than characters because the bound exists to cap what goes on the wire and through a hash, and a character count says nothing about either. Matches the design record’s ≤ 64 bytes, which is far above every username policy this SDK’s apps enforce (user-service caps at 20 characters) — the ceiling is a wire bound, not a policy.

pub fn as_str(&self) -> &str

Returns the normalized username.

This is the form that is hashed, signed and published. A caller that wants the string the user typed must keep it themselves; the protocol only ever sees this one.

pub fn into_string(self) -> String

Consumes the username, returning the normalized string.

Trait Implementations

impl Clone for Username

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Username

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Username

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Re-validates on the way in.

A username arriving in a deserialized record is wire input: it has been normalized by somebody, and that somebody may be an attacker who normalized it differently on purpose. Parsing rather than accepting means a record whose username is not in canonical form fails to deserialize, instead of being compared against a queried name it can never equal.

impl Display for Username

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

Formats the value using the given formatter.

impl Eq for Username

impl FromStr for Username

type Err = UsernameError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Username

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Username

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Username

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Username

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Username

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Username