Refactor select_arguments and slightly change behaviour for non-inner

non inner argument contains the argument, preceeding whitespaces,
and eventual ending comma, except for first arguments (that
contains the whitespaces after the comma), and last argument (that
contains the comma before it).

src/selectors.cc

@@ -434,16 +434,14 @@ Selection select_indent(const Buffer& buffer, const Selection& selection, Object
 Selection select_argument(const Buffer& buffer, const Selection& selection,
                           int level, ObjectFlags flags)
 {
-    auto is_whitespace = [](Codepoint c) {
-        return c == ' ' or c == '\t' or c == '\n';
-    };
-    auto get_kind = [](Codepoint c) -> int {
+    auto get_kind = [](Codepoint c) -> char {
         switch (c)
         {
         case '(': case ')': return 1;
         case '[': case ']': return 2;
         case '{': case '}': return 3;
         case '<': case '>': return 4;
+        default: kak_assert(false); return 0;
         }
     };
     enum Class { None, Opening, Closing };
@@ -456,108 +454,99 @@ Selection select_argument(const Buffer& buffer, const Selection& selection,
         }
     };
 
-    auto pairs = std::vector<int>();
+    Vector<char> pairs;
 
-    Utf8Iterator pos = buffer.iterator_at(selection.cursor());
+    BufferIterator pos = buffer.iterator_at(selection.cursor());
     if (classify(*pos) == Closing)
         ++pos;
-    Utf8Iterator begin = pos;
-    Utf8Iterator end = begin;
-    bool fail = false;
-
-    skip_while(end, buffer.end(), [&](Codepoint cur)
+    bool first_arg = false;
+    BufferIterator begin = pos;
+    for (int lev = level; begin != buffer.begin(); --begin)
     {
-        if (cur == ',' && level == 0)
-        {
-            pairs.push_back(0);
-            return false;
-        }
-        auto c = classify(cur);
-        if (c == Opening)
-        {
-            pairs.push_back(get_kind(cur));
-            ++level;
-        }
-        else if (c == Closing)
-        {
-            --level;
-            if (pairs.empty() || pairs.back() < 0)
-            {
-                pairs.push_back(-get_kind(cur));
-                return level >= 0;
-            }
-            else if (pairs.back() == get_kind(cur))
-            {
-                pairs.pop_back();
-                return true;
-            }
-            fail = true;
-            return false;
-        }
-        return true;
-    });
-    if (fail || end == buffer.end())
-        return selection;
-
-    write_to_debug_buffer("before reverse:");
-    for (auto it = pairs.begin(); it != pairs.end(); ++it)
-        write_to_debug_buffer(format("{}", *it));
-    std::reverse(pairs.begin(), pairs.end());
-    write_to_debug_buffer("before reverse:");
-    for (auto it = pairs.begin(); it != pairs.end(); ++it)
-        write_to_debug_buffer(format("{}", *it));
-
-    --begin;
-    skip_while_reverse(begin, buffer.begin(), [&](Codepoint cur)
-    {
-        if (cur == ',' && pairs.size() == 1)
-        {
-            return false;
-        }
-        auto c = classify(cur);
+        Codepoint cur = *begin;
+        Class c = classify(cur);
         if (c == Closing)
         {
-            pairs.push_back(-get_kind(cur));
+            pairs.push_back(get_kind(cur));
+            ++lev;
         }
         else if (c == Opening)
         {
-            if (pairs.back() == 0 || pairs.back() == -get_kind(cur))
+            if (not pairs.empty())
             {
-                pairs.pop_back();
-                return !pairs.empty();
-            }
-            fail = true;
-            return false;
-        }
-        return true;
-    });
-    if (fail || begin == buffer.begin())
+                if (pairs.back() != get_kind(cur))
                     return selection;
 
+                pairs.pop_back();
+            }
+            if (lev-- == 0)
+            {
+                first_arg = true;
+                ++begin;
+                break;
+            }
+        }
+        else if (cur == ',' and lev == 0)
+        {
+            ++begin;
+            break;
+        }
+    }
+
+    kak_assert(pairs.empty());
+
+    bool last_arg = false;
+    BufferIterator end = pos;
+    for (int lev = level; end != buffer.end(); ++end)
+    {
+        Codepoint cur = *end;
+        Class c = classify(cur);
+        if (c == Opening)
+        {
+            pairs.push_back(get_kind(cur));
+            ++lev;
+        }
+        else if (c == Closing)
+        {
+            if (not pairs.empty())
+            {
+                if (pairs.back() != get_kind(cur))
+                    return selection;
+
+                pairs.pop_back();
+            }
+            if (lev-- == 0)
+            {
+                last_arg = true;
+                --end;
+                break;
+            }
+        }
+        else if (cur == ',' and lev == 0)
+        {
+            // include whitespaces *after* the comma only for first argument
+            if (first_arg and not (flags & ObjectFlags::Inner))
+            {
+                while (end + 1 != buffer.end() and is_blank(*(end+1)))
+                    ++end;
+            }
+            break;
+        }
+    }
+
     if (flags & ObjectFlags::Inner)
     {
-        ++begin;
-        skip_while(begin, end, is_whitespace);
+        if (not last_arg)
             --end;
-        skip_while_reverse(end, begin, is_whitespace);
+        skip_while(begin, end, is_blank);
+        skip_while_reverse(end, begin, is_blank);
     }
-    else
-    {
-        if (classify(*end) == Closing)
-        {
+    // get starting comma for non inner last arg
+    else if (not first_arg and last_arg)
+        --begin;
+
+    if (end == buffer.end())
         --end;
-            if (classify(*begin) == Opening)
-                ++begin;
-        }
-        else
-        {
-            ++begin;
-            skip_while(begin, end, is_whitespace);
-            ++end;
-            skip_while(end, buffer.end(), is_whitespace);
-            --end;
-        }
-    }
 
     if (flags & ObjectFlags::ToBegin and not (flags & ObjectFlags::ToEnd))
         return utf8_range(pos, begin);

src/unicode.hh

@@ -18,6 +18,11 @@ inline bool is_horizontal_blank(Codepoint c)
     return c == ' ' or c == '\t';
 }
 
+inline bool is_blank(Codepoint c)
+{
+    return c == ' ' or c == '\t' or c == '\n';
+}
+
 enum WordType { Word, WORD };
 
 template<WordType word_type = Word>

test/unit/around/argument/multi-level/selections

@@ -1 +1 @@
-(and some, blub and), 
+ (and some, blub and),

test/unit/around/argument/single-level/selections

@@ -1 +1 @@
-"something", 
+ "something",

test/unit/start-extending/argument/selections

@@ -1 +1 @@
-"somethi
+ "somethi