Function reform::sort::split_merge

Important traits for Vec<u8>

impl Write for Vec<u8>

pub fn split_merge<T: Default, F1, F2>(
    terms: &mut [T], 
    cmp: &F1, 
    merger: &F2
) -> Vec<usize> where
    F1: Fn(&T, &T) -> Ordering,
    F2: Fn(&mut T, &mut T) -> bool, 

Sorts a vector of T according to cmp, adds equal elements according to merger, and returns an index map of the (merged) elements in the proper order. We allocate the necessary vectors once and use a separate recursive routine after that. Reading the output properly is done with

let row = sort::split_merge(&mut terms, &cmp, &merger);
let mut out = vec![];
for i in 0..row.len() {
    out.push(terms[row[i]].clone());
}