From 60782b3dc93b7bbc38e148e85dffe2f1ad6a4542 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Tue, 18 Feb 2020 19:26:01 +1100
Subject: [PATCH] Make diff implementation able to work on different iterator
 types

---
 src/diff.hh | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/diff.hh b/src/diff.hh
index 2e719669..20fd53d1 100644
--- a/src/diff.hh
+++ b/src/diff.hh
@@ -24,8 +24,8 @@ struct Snake
     enum Op { Add, Del, RevAdd, RevDel } op;
 };
 
-template<typename Iterator, typename Equal>
-Snake find_end_snake_of_further_reaching_dpath(Iterator a, int N, Iterator b, int M,
+template<typename IteratorA, typename IteratorB, typename Equal>
+Snake find_end_snake_of_further_reaching_dpath(IteratorA a, int N, IteratorB b, int M,
                                                const int* V, const int D, const int k, Equal eq)
 {
     const bool add = k == -D or (k != D and V[k-1] < V[k+1]);
@@ -45,15 +45,16 @@ Snake find_end_snake_of_further_reaching_dpath(Iterator a, int N, Iterator b, in
     return { x, y, u, v, add ? Snake::Add : Snake::Del };
 }
 
-template<typename Iterator, typename Equal>
-Snake find_middle_snake(Iterator a, int N, Iterator b, int M,
+template<typename IteratorA, typename IteratorB, typename Equal>
+Snake find_middle_snake(IteratorA a, int N, IteratorB b, int M,
                         int* V1, int* V2, int cost_limit, Equal eq)
 {
     const int delta = N - M;
     V1[1] = 0;
     V2[1] = 0;
 
-    std::reverse_iterator<Iterator> ra{a + N}, rb{b + M};
+    std::reverse_iterator<IteratorA> ra{a + N};
+    std::reverse_iterator<IteratorB> rb{b + M};
     const int max_D = std::min((M + N + 1) / 2 + 1, cost_limit);
     for (int D = 0; D < max_D; ++D)
     {
@@ -109,9 +110,9 @@ enum class DiffOp
     Remove
 };
 
-template<typename Iterator, typename Equal, typename OnDiff>
-void find_diff_rec(Iterator a, int begA, int endA,
-                   Iterator b, int begB, int endB,
+template<typename IteratorA, typename IteratorB, typename Equal, typename OnDiff>
+void find_diff_rec(IteratorA a, int begA, int endA,
+                   IteratorB b, int begB, int endB,
                    int* V1, int* V2, int cost_limit,
                    Equal eq, OnDiff&& on_diff)
 {
@@ -172,8 +173,8 @@ struct Diff
     int posB;
 };
 
-template<typename Iterator, typename OnDiff, typename Equal = std::equal_to<>>
-void for_each_diff(Iterator a, int N, Iterator b, int M, OnDiff&& on_diff, Equal eq = Equal{})
+template<typename IteratorA, typename IteratorB, typename OnDiff, typename Equal = std::equal_to<>>
+void for_each_diff(IteratorA a, int N, IteratorB b, int M, OnDiff&& on_diff, Equal eq = Equal{})
 {
     const int max = 2 * (N + M) + 1;
     std::unique_ptr<int[]> data(new int[2*max]);