Function distance 

pub fn distance<T: PartialEq, U: AsRef<[T]>>(a: U, b: U) -> usize

Compute the Levenshtein distance between two sequences using identical weights for insertions/deletions and for substitutions.

Examples:

• Compute a distance in characters between two strings:

assert_eq!(distance ("abc", "aaxcc"), 3);

• Compute a distance in words between two strings:

assert_eq!(
   distance (
      "The quick brown fox".split (' ').collect::<Vec<_>>(),
      "The very quick brown cat".split (' ').collect()),
   2);

• Compute a distance between two sequences of anything:

assert_eq!(distance (vec![1, 2, 3], vec![0, 1, 3, 3, 4]), 3);