add sentence (s) object

README.asciidoc

@@ -209,6 +209,7 @@ object you want.
  * _'_: select the enclosing single quoted string
  * _w_: select the whole word
  * _W_: select the whole WORD
+ * _s_: select the sentence
 
 Registers
 ---------

src/normal.cc

@@ -523,6 +523,7 @@ void select_object(Context& context)
             { { Key::Modifiers::None, '\'' }, std::bind(select_surrounding, _1, CodepointPair{ '\'', '\'' }, flags) },
             { { Key::Modifiers::None, 'w' }, std::bind(select_whole_word<false>, _1, flags & SurroundFlags::Inner) },
             { { Key::Modifiers::None, 'W' }, std::bind(select_whole_word<true>, _1, flags & SurroundFlags::Inner) },
+            { { Key::Modifiers::None, 's' }, std::bind(select_whole_sentence, _1, flags & SurroundFlags::Inner) },
         };
 
         auto it = key_to_selector.find(key);

src/selectors.cc

@@ -383,6 +383,44 @@ Selection select_whole_word(const Selection& selection, bool inner)
 template Selection select_whole_word<false>(const Selection&, bool);
 template Selection select_whole_word<true>(const Selection&, bool);
 
+Selection select_whole_sentence(const Selection& selection, bool inner)
+{
+    BufferIterator first = selection.last();
+
+    while (not is_begin(first))
+    {
+        char cur = *first;
+        char prev = *(first-1);
+        if (is_eol(prev) and is_eol(cur))
+        {
+            ++first;
+            break;
+        }
+        else if (prev == '.' or prev == ';')
+            break;
+        --first;
+    }
+    skip_while(first, is_blank);
+
+    BufferIterator last = first;
+    while (not is_end(last))
+    {
+        char cur = *last;
+        if (cur == '.' or cur == ';' or cur == '!' or cur == '?' or
+            (is_eol(cur) and (is_end(last+1) or is_eol(*last+1))))
+            break;
+        ++last;
+    }
+    if (not inner and not is_end(last))
+    {
+        ++last;
+        skip_while(last, is_blank);
+        --last;
+    }
+
+    return Selection{first, last};
+}
+
 Selection select_whole_lines(const Selection& selection)
 {
     // no need to be utf8 aware for is_eol as we only use \n as line seperator

src/selectors.hh

@@ -27,6 +27,7 @@ Selection select_to_eol_reverse(const Selection& selection);
 
 template<bool punctuation_is_word>
 Selection select_whole_word(const Selection& selection, bool inner);
+Selection select_whole_sentence(const Selection& selection, bool inner);
 Selection select_whole_lines(const Selection& selection);
 Selection select_whole_buffer(const Selection& selection);
 Selection trim_partial_lines(const Selection& selection);