Struct Alphabet 

pub struct Alphabet { /* private fields */ }

A validated set of ASCII code symbols.

Implementations

impl Alphabet

pub fn new(symbols: &[u8]) -> Result<Self, PolicyError>

Build an alphabet from raw bytes, validating the invariants required for unbiased generation (RFC-003 §11.1):

• at least 2 symbols,
• all symbols ASCII,
• no duplicate symbols.

Errors

Returns PolicyError if any invariant is violated.

pub fn unambiguous() -> Self

The unambiguous default alphabet (31 symbols).

pub fn len(&self) -> usize

Number of symbols in the alphabet.

pub fn is_empty(&self) -> bool

Whether the alphabet is empty. Always false for a constructed alphabet, present to satisfy clippy and API completeness.

pub fn symbols(&self) -> &[u8]

Borrow the symbols.

pub fn contains(&self, byte: u8) -> bool

Whether byte is a member of this alphabet.

pub fn unbiased_ceiling(&self) -> usize

The rejection-sampling ceiling: the largest multiple of the alphabet length that fits in a byte. Random bytes >= ceiling are discarded to avoid modulo bias (RFC-003 §4, §11.5). For the 31-symbol default this is 256 - (256 % 31) = 248.

Trait Implementations

impl Clone for Alphabet

fn clone(&self) -> Alphabet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Alphabet

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

Formats the value using the given formatter.

impl Eq for Alphabet

impl PartialEq for Alphabet

fn eq(&self, other: &Alphabet) -> 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 Alphabet