Yet Another Variation of Myers for generic containers (for example std::Vec)
This is an implementation of a quasi-Myers algorithm to determine the differences between two generic containers. Its usage is quite simple, for example:
let mut a: Vec<String> = vec!["A", "W", "E", "S", "O", "M", "O"]
.iter()
.map(|s| s.to_string())
.collect();
let b: Vec<String> = vec!["S", "T", "R", "A", "N", "G", "E", "S", "O", "M", "O"]
.iter()
.map(|s| s.to_string())
.collect();
// Create the diff (vector of moves)
let moves = crate::yavom::myers(&a, &b);The return value moves is a vector of Move objects. You can apply moves to the array as follows:
moves.iter().for_each(|m| { crate::yavom::apply_move(m, &mut a); });
// now a's contents are the same as b'sYou can serialize / deserialize Move objects as you deem necessary. To do so please consider the following definitions (found in diff.h):
pub enum OP {
INSERT,
DELETE,
_DELETE,
}
pub struct Point(pub i64, pub i64);
pub struct Move<K>(pub OP, pub Point, pub Point, pub Option<Vec<K>>);The Vec field stores the values to be inserted. For example:
let ops = myers_unfilled(&a, &b);
let mut patch = vec![];
for o in ops {
let Move(op, s, t, _) = o;
match op {
yavomrs::yavom::OP::INSERT => {
let from = s.1 as usize;
let to = (s.1 count) as usize;
let insert_position = s.1;
let values = &new[from..to];
// TODO Serialize INSERT of values at insert_position
}
yavomrs::yavom::OP::DELETE => {
let count = t.0 - s.0;
let delete_position = s.1;
// TODO Serialize DELETE of count values starting from delete_position
}
yavomrs::yavom::OP::_DELETE => {
let Point(count, start) = s;
// TODO Serialize DELETE of count values starting from start
}
}
}
If you are interested in knowning how many moves will be necessary but do not want to generate complete moves (with complete insert data), you can use the myers_unfilled function:
let mut moves = crate::yavom::myers_unfilled(&a, &b);
eprintln!("{} moves", moves.len());Subsequently you can fill the insertion data:
crate::yavom::myers_fill(&b, &mut moves);This code is Copyright (C) 2022 Amos Brocco ([email protected])
BSD 3-Clause License