Struct Counter 

pub struct Counter { /* private fields */ }

Hash-based counter: accumulates (key_tuple → count) without building an intermediate DataFrame. Purpose-built for FAERS drug×event counting.

Implementations

impl Counter

pub fn new(key_names: Vec<String>) -> Self

Create a new counter for the given key columns.

pub fn increment(&mut self, key: Vec<String>)

Increment the count for a key combination.

pub fn increment_by(&mut self, key: Vec<String>, n: u64)

Increment by a specific amount.

pub fn len(&self) -> usize

Number of unique key combinations.

pub fn is_empty(&self) -> bool

Whether no counts have been accumulated.

pub fn get(&self, key: &[String]) -> u64

Get the count for a specific key combination.

pub fn iter(&self) -> impl Iterator<Item = (&Vec<String>, &u64)>

Iterate over all (key, count) pairs.

pub fn total(&self) -> u64

Total count across all keys.

pub fn into_dataframe(self) -> Result<DataFrame, DataFrameError>

Convert the counter into a DataFrame with key columns + a “count” column.

Each unique key combination becomes a row. The last column is always “count”.

pub fn from_dataframe( df: &DataFrame, group_cols: &[&str], ) -> Result<Self, DataFrameError>

Build a counter from a DataFrame by counting rows grouped by specified columns.

pub fn filter_min_count(&self, min_count: u64) -> Self

Filter the counter, keeping only entries where count >= min_count.

Trait Implementations

impl Clone for Counter

fn clone(&self) -> Counter

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Counter

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

Formats the value using the given formatter.