Struct CheckedUnigramId 

pub struct CheckedUnigramId<const N: usize>(/* private fields */);

An identifier of N bytes carrying a trailing check word, rendered as N + 1 alphabet words.

One extra word is 8 bits of CRC over the payload, so every single-word substitution and transposition is caught outright, and an arbitrary accidental mutation with probability about 255/256. Use it where a value has to prove it is the one that was issued without the original in hand.

It detects accidents, not tampering: anyone who can change the payload can recompute the check word. A hostile party calls for a keyed MAC over CheckedUnigramId::as_bytes, which this crate does not provide.

use unigram::{CheckedUnigramId, ParseError};

let id = CheckedUnigramId::from_bytes([1u8, 2, 3, 4]);
let text = id.to_string();
assert_eq!(text.split(' ').count(), 5);          // four payload words, one check
assert_eq!(CheckedUnigramId::<4>::parse(&text).unwrap(), id);

// Swap one word for another valid word: caught, where UnigramId could not.
let mangled = text.replacen("account", "action", 1);
assert!(matches!(
    CheckedUnigramId::<4>::parse(&mangled),
    Err(ParseError::ChecksumMismatch { .. })
));

Implementations

impl<const N: usize> CheckedUnigramId<N>

pub const fn from_bytes(bytes: [u8; N]) -> Self

Wrap bytes that are already in hand. The check word is derived, never stored.

pub fn try_random() -> Result<Self, Error>

Mint N bytes of fresh entropy from the OS CSPRNG.

pub fn parse(text: &str) -> Result<Self, ParseError>

Parse the canonical form and verify the check word.

pub fn recover(text: &str) -> Result<Self, ParseError>

Parse tolerantly and verify the check word.

The pairing worth noting: tolerant parsing is what lets a value survive a round trip, and the check word is what keeps that tolerance from quietly accepting a value the trip changed.

pub const fn as_bytes(&self) -> &[u8; N]

The bytes this identifier carries, without the check word.

pub const fn into_bytes(self) -> [u8; N]

Consume the identifier, yielding its bytes.

pub const fn check_byte(&self) -> u8

The check byte this payload computes.

Trait Implementations

impl<const N: usize> Clone for CheckedUnigramId<N>

fn clone(&self) -> CheckedUnigramId<N>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<const N: usize> Copy for CheckedUnigramId<N>

impl<const N: usize> Debug for CheckedUnigramId<N>

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

Formats the value using the given formatter.

impl<const N: usize> Display for CheckedUnigramId<N>

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

N payload words, then the check word, joined by single spaces.

impl<const N: usize> Eq for CheckedUnigramId<N>

impl<const N: usize> Hash for CheckedUnigramId<N>

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<const N: usize> Ord for CheckedUnigramId<N>

fn cmp(&self, other: &CheckedUnigramId<N>) -> 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.

impl<const N: usize> PartialEq for CheckedUnigramId<N>

fn eq(&self, other: &CheckedUnigramId<N>) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<const N: usize> PartialOrd for CheckedUnigramId<N>

fn partial_cmp(&self, other: &CheckedUnigramId<N>) -> 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<const N: usize> StructuralPartialEq for CheckedUnigramId<N>