unipipes 0.3.1

A small collection of `UniPipe` implementations.
Documentation 
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use std::mem;

use unipipe::{Output, UniPipe, unipipe};

pub struct ChunkWhile<TItem, TPredicate>
where
    TPredicate: FnMut(&mut [TItem], &TItem) -> bool,
{
    chunk: Vec<TItem>,
    predicate: TPredicate,
}

#[unipipe(iterator, try_iterator, stream, try_stream)]
impl<TItem, TPredicate> ChunkWhile<TItem, TPredicate>
where
    TPredicate: FnMut(&mut [TItem], &TItem) -> bool,
{
    pub fn new(predicate: TPredicate) -> Self {
        Self {
            chunk: Vec::new(),
            predicate,
        }
    }
}

impl<TItem, TPredicate> UniPipe for ChunkWhile<TItem, TPredicate>
where
    TPredicate: FnMut(&mut [TItem], &TItem) -> bool,
{
    type Input = TItem;
    type Output = Vec<TItem>;

    fn next(&mut self, input: Option<Self::Input>) -> Output<Self::Output> {
        if let Some(input) = input {
            if self.chunk.is_empty() || (self.predicate)(&mut self.chunk, &input) {
                self.chunk.push(input);

                None
            } else {
                let output = mem::take(&mut self.chunk);

                self.chunk.push(input);

                Some(output)
            }
        } else {
            if self.chunk.is_empty() {
                None
            } else {
                Some(mem::take(&mut self.chunk))
            }
        }
        .into()
    }
}