Function count_distinct_string 

pub fn count_distinct_string<T: Integer>(window: StringAVT<'_, T>) -> usize

Counts the number of distinct string values in a string array window.

Computes the cardinality of unique strings within a windowed portion of a string array, using efficient hash-based deduplication.

Parameters

• window: String array view tuple (StringArray, offset, length) defining the count window

Returns

usize representing the count of distinct non-null string values.

Hash Algorithm

Uses either AHash (if fast_hash feature enabled) or standard HashMap for deduplication.