Struct TermDictionary 

pub struct TermDictionary { /* private fields */ }

A sorted, front-coded term dictionary.

Implementations

impl TermDictionary

pub fn from_map(entries: &BTreeMap<Vec<u8>, TermInfo>) -> Self

Builds a dictionary from an ordered map of terms.

A BTreeMap is required rather than accepted for convenience: it makes the sorted precondition a type-level fact, so the ordering cannot be violated by a caller iterating a hash map.

pub fn push(&mut self, term: &[u8], info: TermInfo) -> Result<(), DictError>

Appends one term. Terms must arrive sorted and unique.

Errors

Returns DictError::NotSorted or DictError::Duplicate.

pub fn len(&self) -> usize

Returns the number of terms.

pub fn is_empty(&self) -> bool

Returns true when the dictionary holds no terms.

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

Returns the front-coded bytes.

pub fn term_at(&self, index: usize) -> Option<&[u8]>

Returns the term at a flat index.

pub fn info_at(&self, index: usize) -> Option<TermInfo>

Returns the information at a flat index.

pub fn get(&self, term: &[u8]) -> Option<TermInfo>

Looks one term up exactly.

pub fn seek_exact(&self, term: &[u8]) -> Option<usize>

Returns the flat index of term, if present.

Binary-searches the materialized block heads, then walks at most one block. This is the operation task 15’s automaton-guided seek repeats.

pub fn seek_ceiling(&self, term: &[u8]) -> Option<usize>

Returns the flat index of the first term at or after term.

This is the primitive task 15’s Levenshtein walk drives: from an automaton state it computes the smallest acceptable next term and seeks here, rather than enumerating the dictionary.

pub fn prefix_range(&self, prefix: &[u8]) -> Result<Range<usize>, DictError>

Returns every flat index whose term starts with prefix.

Errors

Returns DictError::EmptyTerm for an empty prefix. An empty prefix is a full scan wearing a query’s clothes, so it is refused rather than served.

pub fn decode_terms(&self) -> Option<Vec<Vec<u8>>>

Decodes the front-coded bytes back into the term list.

Used by the golden test to prove the encoding is self-describing: the in-memory terms vector is a decode cache, not the source of truth for the persisted form.

Trait Implementations

impl Clone for TermDictionary

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 TermDictionary

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

Formats the value using the given formatter.

impl Default for TermDictionary

fn default() -> Self

Returns the “default value” for a type.