Refactor diff to make allocating a diff vector optional

The diff interface now goes through a for_each_diff function that
uses a callback for each found diff.

1 files changed, 18 insertions, 34 deletions

diff --git a/src/unit_tests.cc b/src/unit_tests.cc
index 54269074..694ad041 100644
--- a/src/unit_tests.cc
+++ b/src/unit_tests.cc
@@ -17,41 +17,25 @@ UnitTest test_utf8{[]()
 
 UnitTest test_diff{[]()
 {
-    auto eq = [](const Diff& lhs, const Diff& rhs) {
-        return lhs.mode == rhs.mode and lhs.len == rhs.len and lhs.posB == rhs.posB;
+    struct Diff{DiffOp op; int len; int posB;};
+    auto check_diff = [](StringView a, StringView b, std::initializer_list<Diff> diffs) {
+        size_t count = 0;
+        for_each_diff(a.begin(), (int)a.length(), b.begin(), (int)b.length(),
+                      [&](DiffOp op, int len, int posB) {
+                          kak_assert(count < diffs.size());
+                          auto& d = diffs.begin()[count++];
+                          kak_assert(d.op == op and d.len == len and d.posB == posB);
+                      });
+        kak_assert(count == diffs.size());
     };
-
-    {
-        auto diff = find_diff("a?", 2, "!", 1);
-        kak_assert(diff.size() == 3 and
-                   eq(diff[0], {Diff::Remove, 1, 0}) and
-                   eq(diff[1], {Diff::Add, 1, 0}) and
-                   eq(diff[2], {Diff::Remove, 1, 0}));
-    }
-
-    {
-        auto diff = find_diff("abcde", 5, "cd", 2);
-        kak_assert(diff.size() == 3 and
-                   eq(diff[0], {Diff::Remove, 2, 0}) and
-                   eq(diff[1], {Diff::Keep, 2, 0}) and
-                   eq(diff[2], {Diff::Remove, 1, 0}));
-    }
-
-    {
-        auto diff = find_diff("abcd", 4, "cdef", 4);
-        kak_assert(diff.size() == 3 and
-                   eq(diff[0], {Diff::Remove, 2, 0}) and
-                   eq(diff[1], {Diff::Keep, 2, 0}) and
-                   eq(diff[2], {Diff::Add, 2, 2}));
-    }
-
-    {
-        StringView s1 = "mais que fais la police";
-        StringView s2 = "mais ou va la police";
-
-        auto diff = find_diff(s1.begin(), (int)s1.length(), s2.begin(), (int)s2.length());
-        kak_assert(diff.size() == 11);
-    }
+    check_diff("a?", "!", {{DiffOp::Remove, 1, 0}, {DiffOp::Add, 1, 0}, {DiffOp::Remove, 1, 0}});
+    check_diff("abcde", "cd", {{DiffOp::Remove, 2, 0}, {DiffOp::Keep, 2, 0}, {DiffOp::Remove, 1, 0}});
+    check_diff("abcd", "cdef", {{DiffOp::Remove, 2, 0}, {DiffOp::Keep, 2, 0}, {DiffOp::Add, 2, 2}});
+
+    check_diff("mais que fais la police", "mais ou va la police",
+               {{DiffOp::Keep, 5, 0}, {DiffOp::Remove, 1, 0}, {DiffOp::Add, 1, 5}, {DiffOp::Keep, 1, 0},
+                {DiffOp::Remove, 1, 0}, {DiffOp::Keep, 1, 0}, {DiffOp::Add, 1, 8}, {DiffOp::Remove, 1, 0}, 
+                {DiffOp::Keep, 1, 0}, {DiffOp::Remove, 2, 0}, {DiffOp::Keep, 10, 0}} );
 }};
 
 UnitTest* UnitTest::list = nullptr;