Struct FilterFold 

pub struct FilterFold<L, S, F, P>
where
    F: Fold<L, S>,
    P: Fn(&L) -> bool,
{ /* private fields */ }

Filter fold — only process entries matching a predicate.

Implementations

impl<L, S, F, P> FilterFold<L, S, F, P>

where F: Fold<L, S>, P: Fn(&L) -> bool,

pub fn new(inner: F, predicate: P) -> Self

Create a filter fold.

Trait Implementations

impl<L, S, F, P> Fold<L, S> for FilterFold<L, S, F, P>

where F: Fold<L, S>, P: Fn(&L) -> bool,

fn initial(&self, context: &FoldContext) -> S

Get the initial state before any entries are processed.

fn step(&self, state: S, entry: &L, context: &FoldContext) -> S

Process a single entry and return the new state.

fn finalize(&self, state: S, context: &FoldContext) -> S

Finalize the state after all entries are processed.

fn derive<'a, I>(&self, entries: I, context: &FoldContext) -> FoldOutcome<S>

where Self: Sized, I: IntoIterator<Item = &'a L>, L: 'a,

Derive state from an iterator of entries.

fn derive_filtered<'a, I, F>( &self, entries: I, context: &FoldContext, filter: F, ) -> FoldOutcome<S>

where Self: Sized, I: IntoIterator<Item = &'a L>, L: 'a, F: Fn(&L) -> bool,

Derive state with a filter.