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use std::collections::hash_map::Entry;
use std::collections::HashMap;
use std::hash::Hash;
use {myers, Diff, Replace};
#[derive(Debug)]
struct I<'a, A: 'a> {
p: &'a [A],
i: usize,
}
#[cfg(test)]
impl<'a, A: std::fmt::Debug + 'a> std::fmt::Debug for I<'a, A> {
fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(fmt, "{:?}", self.p[self.i])
}
}
impl<'a, 'b, A: 'a, B: PartialEq<A> + 'b> PartialEq<I<'a, A>> for I<'b, B> {
fn eq(&self, b: &I<'a, A>) -> bool {
self.p[self.i] == b.p[b.i]
}
}
fn unique<A: Hash + Eq>(p: &[A]) -> Vec<I<A>> {
let mut aa = HashMap::new();
for (i, a) in p.iter().enumerate() {
match aa.entry(a) {
Entry::Vacant(e) => {
e.insert(Some(i));
}
Entry::Occupied(mut e) => {
let e = e.get_mut();
if e.is_some() {
*e = None
}
}
}
}
let mut v: Vec<_> = aa
.into_iter()
.filter_map(|(_, x)| x)
.map(|i| I { p, i })
.collect();
v.sort_by(|a, b| a.i.cmp(&b.i));
v
}
pub fn diff<
A: Hash + Eq, B: Hash + Eq + PartialEq<A>, D: Diff,
>(
d: &mut D,
a: &[A],
b: &[B],
) -> Result<(), D::Error> {
let au = unique(a);
let bu = unique(b);
struct Patience<'a, 'b, 'd, A: 'a, B: 'b, D: Diff + 'd> {
current_a: usize,
current_b: usize,
a: &'a [A],
b: &'b [B],
d: &'d mut D,
au: &'a [I<'a, A>],
bu: &'b [I<'b, B>],
}
impl<
'a,
'b,
'd,
A: 'a, B: 'b + PartialEq<A>, D: Diff + 'd,
> Diff for Patience<'a, 'b, 'd, A, B, D>
{
type Error = D::Error;
fn equal(&mut self, old: usize, new: usize, len: usize) -> Result<(), D::Error> {
for (old, new) in (old..old + len).zip(new..new + len) {
let a0 = self.current_a;
let b0 = self.current_b;
while self.current_a < self.au[old].i
&& self.current_b < self.bu[new].i
&& self.b[self.current_b] == self.a[self.current_a]
{
self.current_a += 1;
self.current_b += 1;
}
if self.current_a > a0 {
self.d.equal(a0, b0, self.current_a - a0)?
}
let a = &self.a[self.current_a..self.au[old].i];
let b = &self.b[self.current_b..self.bu[new].i];
myers::diff_offsets(self.d, a, b, self.current_a, self.current_b)?;
self.current_a = self.au[old].i;
self.current_b = self.bu[new].i;
}
Ok(())
}
fn finish(&mut self) -> Result<(), D::Error> {
let a = &self.a[self.current_a..];
let b = &self.b[self.current_b..];
myers::diff_offsets(self.d, a, b, self.current_a, self.current_b)?;
self.d.finish()
}
}
let mut d = Replace::new(Patience {
current_a: 0,
current_b: 0,
a,
b,
d,
au: &au,
bu: &bu,
});
myers::diff(&mut d, &au, &bu)?;
Ok(())
}
#[test]
fn patience() {
let a: &[usize] = &[11, 1, 2, 2, 3, 4, 4, 4, 5, 47, 19];
let b: &[usize] = &[10, 1, 2, 2, 8, 9, 4, 4, 7, 47, 18];
struct D {}
impl Diff for D {
type Error = ();
fn equal(&mut self, o: usize, n: usize, len: usize) -> Result<(), ()> {
println!("equal {:?} {:?} {:?}", o, n, len);
Ok(())
}
fn delete(&mut self, o: usize, len: usize) -> Result<(), ()> {
println!("delete {:?} {:?}", o, len);
Ok(())
}
fn insert(&mut self, o: usize, n: usize, len: usize) -> Result<(), ()> {
println!("insert {:?} {:?} {:?}", o, n, len);
Ok(())
}
fn replace(&mut self, o: usize, l: usize, n: usize, nl: usize) -> Result<(), ()> {
println!("replace {:?} {:?} {:?} {:?}", o, l, n, nl);
Ok(())
}
}
let mut d = Replace::new(D {});
diff(&mut d, a, b).unwrap();
}