Crate alcs

Implementation of An all-substrings common subsequence algorithm

Given two strings s1 and s2, it is possible construct, in O(|s1|*|s2|) time and O(|s1|+|s2|) space, a structure that can be queried to find the length of all Longest Common Subsequences between s1 and all possible substrings of s2, each query requiring constant time.

Some accessor functions are provided to retrieve the matrices and the vectors defined in the paper

# Example

extern crate alcs;
 use alcs::Alcs;

 fn main() {
    let a = "word";
    let b = "hello world";
    let va = a.chars().collect::<Vec<char>>();
    let vb = b.chars().collect::<Vec<char>>();
    let alcs = Alcs::new(&va, &vb);
    for i in 0..b.len() {
        for (i, j, cij) in alcs.suffix(i) {
            println!(r#"LCS between "{}" and "{}" has length {}"#,a,&b[i..j],cij);
        }
     }
 }

Output:

LCS between "word" and "h" has length 0
 LCS between "word" and "he" has length 0
 LCS between "word" and "hel" has length 0
 ...
 LCS between "word" and " world" has length 4
 LCS between "word" and "w" has length 1
 LCS between "word" and "wo" has length 2
 LCS between "word" and "wor" has length 3
 ...
 LCS between "word" and "d" has length 1

Also, it is defined a trait that allows to fuzzy search a string:

extern crate alcs;
 use alcs::FuzzyStrstr;

 fn main() {
    let tsh = 0.7;
    let tests = [
        ("he.llo.wor.ld.!", "world"),
        ("he.llo.word", "world"),
        ("hello world", "word"),
        ("hello world", "banana"),
    ];
    for &(h, n) in &tests {
        match h.fuzzy_find_str(n, tsh) {
            None => {
                println!(r#""{}" does not contain "{}""#, h, n);
            }
            Some((score, sub)) => {
                println!(r#""{}" contains "{}" ("{}") with score {}"#, h, n, sub, score);
            }
        }
    }
 }

Output:

"he.llo.wor.ld.!" contains "world" ("wor.ld") with score 0.8333333
 "he.llo.word" contains "world" ("word") with score 0.8
 "hello world" contains "word" ("world") with score 0.8
 "hello world" does not contain "banana"

Structs

Alcs
AlcsIterator

Traits

FuzzyStrstr

Functions

alcs	Constructs the vectors IG, VG, DG0
alcs_mat	Constructs the matrices ih, iv, and the vectors IG, VG, DG0
compute_ig_vg_dg_from_ih_mat	Constructs the vectors DG0 and VG using the matrix ih
compute_mat_ih_iv	Constructs the full matrices i_h and i_v
compute_vec_ig	Constructs the vector IG
compute_vg_dg_from_ig	Constructs the vectors DG0 and VG using IG