diff --git a/src/main.cc b/src/main.cc
index e80f5717..6aa35004 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -59,15 +59,9 @@ void register_env_vars()
         }, {
             "buflist",
             [](StringView name, const Context& context)
-            {
-                String res;
-                for (auto& buf : BufferManager::instance())
-                {
-                    if (not res.empty())
-                        res += ":";
-                    res += buf->display_name();
-                }
-                return res; }
+            { return join(transformed(BufferManager::instance(),
+                                      [](const safe_ptr<Buffer>& b)
+                                      { return b->display_name(); }), ':'); }
         }, {
             "timestamp",
             [](StringView name, const Context& context)
@@ -80,15 +74,7 @@ void register_env_vars()
         }, {
             "selections",
             [](StringView name, const Context& context)
-            { auto sels = context.selections_content();
-              String res;
-              for (size_t i = 0; i < sels.size(); ++i)
-              {
-                  res += escape(sels[i], ':', '\\');
-                  if (i != sels.size() - 1)
-                      res += ':';
-              }
-              return res; }
+            { return join(context.selections_content(), ':'); }
         }, {
             "runtime",
             [](StringView name, const Context& context)
@@ -130,24 +116,17 @@ void register_env_vars()
             "selection_desc",
             [](StringView name, const Context& context)
             { auto& sel = context.selections().main();
-                auto beg = sel.min();
-                return to_string(beg.line + 1) + "." + to_string(beg.column + 1) + "+" +
-                       to_string((int)context.buffer().distance(beg, sel.max())+1); }
+              auto beg = sel.min();
+              return to_string(beg.line + 1) + "." + to_string(beg.column + 1) + "+" +
+                     to_string((int)context.buffer().distance(beg, sel.max())+1); }
         }, {
             "selections_desc",
             [](StringView name, const Context& context)
-            {
-                String res;
-                for (auto& sel : context.selections())
-                {
+            { return join(transformed(context.selections(), [&](const Selection& sel) {
                     auto beg = sel.min();
-                    if (not res.empty())
-                        res += ':';
-                    res += to_string(beg.line + 1) + "." + to_string(beg.column + 1) + "+" +
+                    return to_string(beg.line + 1) + "." + to_string(beg.column + 1) + "+" +
                            to_string((int)context.buffer().distance(beg, sel.max())+1);
-                }
-                return res;
-            }
+                }), ':'); }
         }, {
             "window_width",
             [](StringView name, const Context& context)
diff --git a/src/normal.cc b/src/normal.cc
index 13f1fb7c..35eb4db3 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -721,7 +721,7 @@ void split_lines(Context& context, NormalParams)
     selections = std::move(res);
 }
 
-void join_select_spaces(Context& context, NormalParams)
+void join_lines_select_spaces(Context& context, NormalParams)
 {
     auto& buffer = context.buffer();
     std::vector<Selection> selections;
@@ -746,7 +746,7 @@ void join_select_spaces(Context& context, NormalParams)
     context.selections().insert(" "_str, InsertMode::Replace);
 }
 
-void join(Context& context, NormalParams params)
+void join_lines(Context& context, NormalParams params)
 {
     SelectionList sels{context.selections()};
     auto restore_sels = on_scope_end([&]{
@@ -754,7 +754,7 @@ void join(Context& context, NormalParams params)
         context.selections() = std::move(sels);
     });
 
-    join_select_spaces(context, params);
+    join_lines_select_spaces(context, params);
 }
 
 template<bool matching>
@@ -1430,8 +1430,8 @@ KeyMap keymap =
     { alt('{'), { "extend to inner object start", select_object<ObjectFlags::ToBegin | ObjectFlags::Inner, SelectMode::Extend> } },
     { alt('}'), { "extend to inner object end", select_object<ObjectFlags::ToEnd | ObjectFlags::Inner, SelectMode::Extend> } },
 
-    { alt('j'), { "join lines", join } },
-    { alt('J'), { "join lines and select spaces", join_select_spaces } },
+    { alt('j'), { "join lines", join_lines } },
+    { alt('J'), { "join lines and select spaces", join_lines_select_spaces } },
 
     { alt('k'), { "keep selections matching given regex", keep<true> } },
     { alt('K'), { "keep selections not matching given regex", keep<false> } },
diff --git a/src/string.hh b/src/string.hh
index 91df1b98..8cbd7a68 100644
--- a/src/string.hh
+++ b/src/string.hh
@@ -235,6 +235,19 @@ std::vector<StringView> split(StringView str, char separator);
 String escape(StringView str, StringView characters, char escape);
 String unescape(StringView str, StringView characters, char escape);
 
+template<typename Container>
+String join(const Container& container, char joiner)
+{
+    String res;
+    for (const auto& str : container)
+    {
+        if (not res.empty())
+            res += joiner;
+        res += escape(str, joiner, '\\');
+    }
+    return res;
+}
+
 inline String operator"" _str(const char* str, size_t)
 {
     return String(str);