Change to use sets instead of vectors

This simplifies the editing handlers.

src/main.cpp

@@ -28,34 +28,32 @@ using namespace std;
 set<string> additions;
 string change;
 map<string, string> changes;
-vector<string> deletions;
+set<string> deletions;
 bool should_list = false;
 
-static void handle_additions(vector<string>& cur_tags) {
-    set<string> tags {cur_tags.begin(), cur_tags.end()};
+static void handle_additions(set<string>& tags) {
     tags.insert(additions.begin(), additions.end());
-    cur_tags.clear();
-    copy(tags.begin(), tags.end(), back_inserter(cur_tags));
 }
 
-static void handle_changes(vector<string>& tags) {
+static void handle_changes(set<string>& tags) {
     for (const auto& elem : changes) {
-        auto it = find(tags.begin(), tags.end(), elem.first);
+        auto it = tags.find(elem.first);
         if (it != tags.end()) {
-            *it = elem.second;
+            tags.erase(*it);
+            tags.insert(elem.second);
         }
     }
 }
 
-static void handle_deletions(vector<string>& tags) {
-    for (const string& tag : deletions) {
-        tags.erase(remove(tags.begin(), tags.end(), tag), tags.end());
-    }
+static void handle_deletions(set<string>& tags) {
+    set_difference(tags.begin(), tags.end(),
+                   deletions.begin(), deletions.end(),
+                   inserter(tags, tags.begin()));
 }
 
 static void process(const char* path) {
     const char* tagname {"user.xdg.tags"};
-    vector<string> tags;
+    set<string> tags;
     vector<char> buf(1024);
     ssize_t sz = 0;
     do {
@@ -72,24 +70,31 @@ static void process(const char* path) {
     } while (sz == -1 && errno == ERANGE);
     if (sz > 0) {
         string val(buf.data(), sz);
-        tags = sc::split(val, ",");
+        vector<string> cur_tags = sc::split(val, ",");
+        tags.insert(cur_tags.begin(), cur_tags.end());
     }
     bool edits = additions.size() > 0 || changes.size() > 0 || deletions.size() > 0;
     if (edits) {
         if (should_list) {
             cout << path << '\n';
-            cout << "  before: " << sc::io::greenf << sc::join(tags, ", ") << sc::io::reset << '\n';
+            cout << "  before: " << sc::io::greenf
+                 << sc::join(tags.begin(), tags.end(), ", ")
+                 << sc::io::reset << '\n';
         }
         handle_deletions(tags);
         handle_changes(tags);
         handle_additions(tags);
         if (should_list) {
-            cout << "   after: " << sc::io::yellowf << sc::join(tags, ", ") << sc::io::reset << '\n';
+            cout << "   after: " << sc::io::yellowf
+                 << sc::join(tags.begin(), tags.end(), ", ")
+                 << sc::io::reset << '\n';
         }
-        string joined {sc::join(tags, ",")};
+        string joined {sc::join(tags.begin(), tags.end(), ",")};
         throw_if_min1(setxattr(path, tagname, joined.c_str(), joined.size(), 0));
     } else {
-        cout << path << ": " << sc::io::yellowf << sc::join(tags, ", ") << sc::io::reset << '\n';
+        cout << path << ": " << sc::io::yellowf
+             << sc::join(tags.begin(), tags.end(), ", ")
+             << sc::io::reset << '\n';
     }
 }
 
@@ -131,7 +136,7 @@ int main(int argc, char* argv[]) {
                 }
                 case 'a': additions.insert(arg); break;
                 case 'c': change = arg; break;
-                case 'd': deletions.push_back(arg); break;
+                case 'd': deletions.insert(arg); break;
                 case 'h': print_help(); return EXIT_SUCCESS;
                 case 'i': changes.emplace(change, arg); break;
                 case 'l': should_list = true; break;