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#![allow(clippy::inline_always)]
use std::hash::Hash;
// -----------------------------------------------------------------------------
impl<K: Hash + Ord> crate::simple::search_index::SearchIndex<K> {
/// This search function will return keys as the search results. Each
/// resulting key can then be used to retrieve the full record from its
/// collection. _This search method only accepts a single keyword as the
/// search string._ Search keywords must be an exact match.
///
/// Search only supports exact keyword matches and does not use fuzzy
/// matching. Consider providing the `autocomplete` feature to your users as
/// an ergonomic alternative to fuzzy matching.
///
/// Note: This function is lower-level and for internal use only. It does
/// not observe any settings such as _case-sensitivity_ or _maximum
/// results_. These constraints should be observed at higher levels.
#[inline]
#[allow(clippy::map_unwrap_or)] // `map_or_else` is illegible
pub(crate) fn internal_keyword_search(
&self,
keyword: &str,
) -> impl Iterator<Item = &K> {
// Attempt to get matching keys for the search keyword from BTreeMap:
self.b_tree_map
.get(keyword)
// Return an iterator over the keys for the keyword:
.map(|keys| keys
// Iterate over all matching keys and only return
// `maximum_keys_per_keyword` number of keys:
.iter()
// Only return `maximum_keys_per_keyword` number of keys.
.take(self.maximum_keys_per_keyword)
)
// If there are no keys for the keyword, then return an empty
// iterator. The `empty_b_tree_set` allows us to trick the compiler
// into returning an empty iterator.
.unwrap_or_else(|| self.empty_b_tree_set
.iter()
.take(self.maximum_keys_per_keyword))
} // fn
} // impl