pub fn new_from_input_arities(arities: Vec<usize>) -> Self {
        let mut offset = 0;
        let mut prior_arities = Vec::new();
        for input in 0..arities.len() {
            prior_arities.push(offset);
            offset += arities[input];
        }

        let input_relation = arities
            .iter()
            .enumerate()
            .flat_map(|(r, a)| std::iter::repeat(r).take(*a))
            .collect::<Vec<_>>();

        JoinInputMapper {
            arities,
            input_relation,
            prior_arities,
        }
    }
/// Creates a new `JoinInputMapper` and calculates the mapping of global context
/// columns to local context columns. Using this method saves is more
/// efficient if input arities have been pre-calculated
Creates a new `JoinInputMapper` and calculates the mapping of global context
columns to local context columns. Using this method saves is more
efficient if input arities have been pre-calculated
Creates a new ` JoinInputMapper ` and calculates the mapping of global context columns to local context columns . Using this method saves is more efficient if input arities have been pre - calculated
pub fn new_from_input_arities(arities: Vec<usize>) -> Self {
        let mut offset = 0;
        let mut prior_arities = Vec::new();
        for input in 0..arities.len() {
            prior_arities.push(offset);
            offset += arities[input];
        }
        let input_relation = arities
            .iter()
            .enumerate()
            .flat_map(|(r, a)| std::iter::repeat(r).take(*a))
            .collect::<Vec<_>>();
        JoinInputMapper {
            arities,
            input_relation,
            prior_arities,
        }
    }
pub fn new_from_input_arities ( arities : Vec < usize > ) -> Self { let mut offset = 0 ; let mut prior_arities = Vec :: new ( ) ; for input in 0 .. arities . len ( ) { prior_arities . push ( offset ) ; offset += arities [ input ] ; } let input_relation = arities . iter ( ) . enumerate ( ) . flat_map ( | ( r , a ) | std :: iter :: repeat ( r ) . take ( * a ) ) . collect :: < Vec < _ > > ( ) ; JoinInputMapper { arities , input_relation , prior_arities , } }
Creates a new `JoinInputMapper` and calculates the mapping of global context
columns to local context columns.
Creates a new ` JoinInputMapper ` and calculates the mapping of global context columns to local context columns .
arities
Vec<usize>
arities
Vec<usize>