Sorting methods

Type le

type le<T> = fn(T, T) -> bool

Function merge_sort

fn merge_sort<T: copy>(le: le<T>, v: ~[const T]) -> ~[T]

Merge sort. Returns a new vector containing the sorted list.

Has worst case O(n log n) performance, best case O(n), but is not space efficient. This is a stable sort.

Function quick_sort

fn quick_sort<T: copy>(compare_func: le<T>, arr: ~[mut T])

Quicksort. Sorts a mut vector in place.

Has worst case O(n^2) performance, average case O(n log n). This is an unstable sort.

Function quick_sort3

fn quick_sort3<T: copy ord eq>(arr: ~[mut T])

Fancy quicksort. Sorts a mut vector in place.

Based on algorithm presented by [Sedgewick and Bentley]/~ (http://www.cs.princeton.edu/~rs/talks/QuicksortIsOptimal.pdf). According to these slides this is the algorithm of choice for 'randomly ordered keys, abstract compare' & 'small number of key values'.

This is an unstable sort.