Struct SubTrie 

pub struct SubTrie<'a, T> { /* private fields */ }

View over the subset of a CommandTrie whose keys share a common prefix.

Construct via CommandTrie::subtrie. Guaranteed non-empty.

Implementations

impl<'a, T> SubTrie<'a, T>

pub fn common_prefix(&self) -> &str

Longest prefix shared by every entry in the view.

pub fn extension(&self) -> &str

Bytes between the originally queried prefix and Self::common_prefix.

This is exactly what a fish-style line editor should splice into the buffer on TAB: the unambiguous auto-extension implied by what the user has typed so far. Empty when the typed prefix is already at a branch point (caller should then display the menu of completions).

pub fn is_unique(&self) -> bool

true when exactly one entry matches — the caller can commit it and stop prompting. O(1).

pub fn value(&self) -> Option<&'a T>

Value at this view’s deepest node, when that node itself holds a value (i.e. Self::common_prefix is itself a stored key). Returns None for a pure branch-point view.

pub fn unique_value(&self) -> Option<&'a T>

The single matching value when this view contains exactly one entry, else None. Combines Self::is_unique and Self::value; spares the caller a follow-up trie.get(sub.common_prefix()).

pub fn len(&self) -> usize

Number of entries in the view. Walks the subtrie.

pub fn is_empty(&self) -> bool

Always false — a SubTrie only exists when at least one entry matches.

pub fn iter(&self) -> Iter<'a, T>

Iterator over (key, value) pairs in this view, alphabetically.

Clones common_prefix into the iterator’s buffer. If you only walk the view once, prefer subtrie.into_iter(), which moves the buffer in instead.

pub fn for_each(&self, f: impl FnMut(&str, &T))

Visit every entry in the view without allocating per match.

Trait Implementations

impl<'a, T: Clone> Clone for SubTrie<'a, T>

fn clone(&self) -> SubTrie<'a, T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for SubTrie<'_, T>

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

Formats the value using the given formatter.

impl<'a, T> IntoIterator for &SubTrie<'a, T>

type Item = (String, &'a T)

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, T> IntoIterator for SubTrie<'a, T>

fn into_iter(self) -> Self::IntoIter

Moves common_prefix into the iterator’s buffer, avoiding the clone that (&subtrie).into_iter() would perform.

type Item = (String, &'a T)

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?