Struct datafrog::ValueFilter

pub struct ValueFilter<Tuple, Val, Func: Fn(&Tuple, &Val) -> bool> { /* fields omitted */ }

A treefrog leaper based on a predicate of prefix and value. Use like ValueFilter::from(|tuple, value| ...). The closure should return true if value ought to be retained. The value will be a value proposed elsewhere by an extend_with leaper.

This leaper cannot be used in isolation, it must be combined with other leapers.

Implementations

impl<'leap, Tuple, Val, Func> ValueFilter<Tuple, Val, Func> where
    Func: Fn(&Tuple, &Val) -> bool, 

pub fn from(predicate: Func) -> Self

Creates a new filter based on the prefix

Trait Implementations

impl<'leap, Tuple, Val, Func> Leaper<'leap, Tuple, Val> for ValueFilter<Tuple, Val, Func> where
    Func: Fn(&Tuple, &Val) -> bool, 

fn count(&mut self, _prefix: &Tuple) -> usize

Estimates the number of proposed values.

fn propose(&mut self, _prefix: &Tuple, _values: &mut Vec<&'leap Val>)

Populates values with proposed values.

fn intersect(&mut self, prefix: &Tuple, values: &mut Vec<&'leap Val>)

Restricts values to proposed values.