Buffer: insert and erase go back to taking iterators, and return iterators

9 files changed, 95 insertions, 103 deletions

diff --git a/src/buffer.cc b/src/buffer.cc
index 1b95fe9c..f46049de 100644
--- a/src/buffer.cc
+++ b/src/buffer.cc
@@ -412,12 +412,12 @@ void Buffer::check_invariant() const
 #endif
 }
 
-void Buffer::do_insert(const BufferCoord& pos, const String& content)
+BufferCoord Buffer::do_insert(const BufferCoord& pos, const String& content)
 {
     kak_assert(is_valid(pos));
 
     if (content.empty())
-        return;
+        return pos;
 
     ++m_timestamp;
     ByteCount offset = this->offset(pos);
@@ -489,9 +489,10 @@ void Buffer::do_insert(const BufferCoord& pos, const String& content)
 
     for (auto listener : m_change_listeners)
         listener->on_insert(*this, begin, end);
+    return begin;
 }
 
-void Buffer::do_erase(const BufferCoord& begin, const BufferCoord& end)
+BufferCoord Buffer::do_erase(const BufferCoord& begin, const BufferCoord& end)
 {
     kak_assert(is_valid(begin));
     kak_assert(is_valid(end));
@@ -501,19 +502,25 @@ void Buffer::do_erase(const BufferCoord& begin, const BufferCoord& end)
     String suffix = m_lines[end.line].content.substr(end.column);
     Line new_line = { m_lines[begin.line].start, prefix + suffix };
 
+    BufferCoord next;
     if (new_line.length() != 0)
     {
         m_lines.erase(m_lines.begin() + (int)begin.line, m_lines.begin() + (int)end.line);
         m_lines[begin.line] = std::move(new_line);
+        next = begin;
     }
     else
+    {
         m_lines.erase(m_lines.begin() + (int)begin.line, m_lines.begin() + (int)end.line + 1);
+        next = is_end(begin) ? end_coord() : BufferCoord{begin.line, 0};
+    }
 
     for (LineCount i = begin.line+1; i < line_count(); ++i)
         m_lines[i].start -= length;
 
     for (auto listener : m_change_listeners)
         listener->on_erase(*this, begin, end);
+    return next;
 }
 
 void Buffer::apply_modification(const Modification& modification)
@@ -547,32 +554,33 @@ void Buffer::apply_modification(const Modification& modification)
     }
 }
 
-void Buffer::insert(BufferCoord pos, String content)
+BufferIterator Buffer::insert(const BufferIterator& pos, String content)
 {
-    kak_assert(is_valid(pos));
+    kak_assert(is_valid(pos.coord()));
     if (content.empty())
-        return;
+        return pos;
 
-    if (is_end(pos) and content.back() != '\n')
+    if (pos == end() and content.back() != '\n')
         content += '\n';
 
     if (not (m_flags & Flags::NoUndo))
-        m_current_undo_group.emplace_back(Modification::Insert, pos, content);
-    do_insert(pos, content);
+        m_current_undo_group.emplace_back(Modification::Insert, pos.coord(), content);
+    return {*this, do_insert(pos.coord(), content)};
 }
 
-void Buffer::erase(BufferCoord begin, BufferCoord end)
+BufferIterator Buffer::erase(BufferIterator begin, BufferIterator end)
 {
-    if (is_end(end) and (begin.column != 0 or begin == BufferCoord{0,0}))
-        end = { line_count() - 1, m_lines.back().length() - 1};
+    // do not erase last \n except if we erase from the start of a line
+    if (end == this->end() and (begin.coord().column != 0 or begin == this->begin()))
+        --end;
 
     if (begin == end)
-        return;
+        return begin;
 
     if (not (m_flags & Flags::NoUndo))
-        m_current_undo_group.emplace_back(Modification::Erase, begin,
-                                          string(begin, end));
-    do_erase(begin, end);
+        m_current_undo_group.emplace_back(Modification::Erase, begin.coord(),
+                                          string(begin.coord(), end.coord()));
+    return {*this, do_erase(begin.coord(), end.coord())};
 }
 
 bool Buffer::is_modified() const
diff --git a/src/buffer.hh b/src/buffer.hh
index 26fa584a..61b9179e 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -100,8 +100,8 @@ public:
 
     bool set_name(String name);
 
-    void insert(BufferCoord pos, String content);
-    void erase(BufferCoord begin, BufferCoord end);
+    BufferIterator insert(const BufferIterator& pos, String content);
+    BufferIterator erase(BufferIterator begin, BufferIterator end);
 
     size_t         timestamp() const { return m_timestamp; }
 
@@ -160,8 +160,6 @@ public:
 
     void check_invariant() const;
 private:
-    friend class BufferIterator;
-
     struct Line
     {
         ByteCount start;
@@ -179,8 +177,8 @@ private:
     };
     LineList m_lines;
 
-    void do_insert(const BufferCoord& pos, const String& content);
-    void do_erase(const BufferCoord& begin, const BufferCoord& end);
+    BufferCoord do_insert(const BufferCoord& pos, const String& content);
+    BufferCoord do_erase(const BufferCoord& begin, const BufferCoord& end);
 
     String  m_name;
     Flags   m_flags;
diff --git a/src/commands.cc b/src/commands.cc
index b46b1b63..4e62a65f 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -60,9 +60,8 @@ Buffer* open_fifo(const String& name , const String& filename, Context& context)
         constexpr size_t buffer_size = 1024 * 16;
         char data[buffer_size];
         ssize_t count = read(watcher.fd(), data, buffer_size);
-        buffer->insert(buffer->back_coord(),
-                       count > 0 ? String(data, data+count)
-                                  : "*** kak: fifo closed ***\n");
+        buffer->insert(buffer->end()-1, count > 0 ? String(data, data+count)
+                                                  : "*** kak: fifo closed ***\n");
         ClientManager::instance().redraw_clients();
         if (count <= 0)
         {
diff --git a/src/editor.cc b/src/editor.cc
index 81abd0e4..5d2e4a81 100644
--- a/src/editor.cc
+++ b/src/editor.cc
@@ -44,43 +44,31 @@ void Editor::erase()
     }
 }
 
-static BufferCoord prepare_insert(Buffer& buffer, const Selection& sel,
-                                  InsertMode mode)
+static BufferIterator prepare_insert(Buffer& buffer, const Selection& sel,
+                                     InsertMode mode)
 {
     switch (mode)
     {
     case InsertMode::Insert:
-        return sel.min();
+        return buffer.iterator_at(sel.min());
     case InsertMode::Replace:
-    {
-        BufferCoord pos = sel.min();
-        Kakoune::erase(buffer, sel);
-        return pos;
-    }
+        return Kakoune::erase(buffer, sel);
     case InsertMode::Append:
     {
         // special case for end of lines, append to current line instead
-        auto& pos = std::max(sel.first(), sel.last());
-        if (pos.column == buffer[pos.line].length() - 1)
-            return pos;
-        else
-            return buffer.char_next(pos);
+        auto pos = buffer.iterator_at(sel.max());
+        return *pos == '\n' ? pos : utf8::next(pos);
     }
     case InsertMode::InsertAtLineBegin:
-        return sel.min().line;
+        return buffer.iterator_at(sel.min().line);
     case InsertMode::AppendAtLineEnd:
-        return {sel.max().line, buffer[sel.max().line].length() - 1};
+        return buffer.iterator_at({sel.max().line, buffer[sel.max().line].length() - 1});
     case InsertMode::InsertAtNextLineBegin:
-        return sel.max().line+1;
+        return buffer.iterator_at(sel.max().line+1);
     case InsertMode::OpenLineBelow:
+        return buffer.insert(buffer.iterator_at(sel.max().line + 1), "\n");
     case InsertMode::OpenLineAbove:
-    {
-        auto line = mode == InsertMode::OpenLineAbove ?
-            sel.min().line : sel.max().line + 1;
-        buffer.insert(line, "\n");
-        return line;
-    }
-
+        return buffer.insert(buffer.iterator_at(sel.min().line), "\n");
     }
     kak_assert(false);
     return {};
@@ -92,13 +80,13 @@ void Editor::insert(const String& str, InsertMode mode)
 
     for (auto& sel : m_selections)
     {
-        BufferCoord pos = prepare_insert(*m_buffer, sel, mode);
-        m_buffer->insert(pos, str);
-        if (mode == InsertMode::Replace and not m_buffer->is_end(pos))
+        auto pos = prepare_insert(*m_buffer, sel, mode);
+        pos = m_buffer->insert(pos, str);
+        if (mode == InsertMode::Replace and pos != m_buffer->end())
         {
-            sel.first() = pos;
+            sel.first() = pos.coord();
             sel.last()  = str.empty() ?
-                 pos : m_buffer->advance(pos, str.byte_count_to(str.char_length() - 1));
+                 pos.coord() : (pos + str.byte_count_to(str.char_length() - 1)).coord();
         }
         avoid_eol(*m_buffer, sel);
     }
@@ -114,14 +102,14 @@ void Editor::insert(const memoryview<String>& strings, InsertMode mode)
     for (size_t i = 0; i < selections().size(); ++i)
     {
         auto& sel = m_selections[i];
-        BufferCoord pos = prepare_insert(*m_buffer, sel, mode);
+        auto pos = prepare_insert(*m_buffer, sel, mode);
         const String& str = strings[std::min(i, strings.size()-1)];
-        m_buffer->insert(pos, str);
-        if (mode == InsertMode::Replace and not m_buffer->is_end(pos))
+        pos = m_buffer->insert(pos, str);
+        if (mode == InsertMode::Replace and pos != m_buffer->end())
         {
-            sel.first() = pos;
-            sel.last()  = str.empty() ?
-                 pos : m_buffer->advance(pos, str.byte_count_to(str.char_length() - 1));
+            sel.first() = pos.coord();
+            sel.last()  = (str.empty() ?
+                           pos : pos + str.byte_count_to(str.char_length() - 1)).coord();
         }
         avoid_eol(*m_buffer, sel);
     }
@@ -462,27 +450,24 @@ IncrementalInserter::IncrementalInserter(Editor& editor, InsertMode mode)
         BufferCoord first, last;
         switch (mode)
         {
-        case InsertMode::Insert:  first = sel.max(); last = sel.min(); break;
+        case InsertMode::Insert:
+            first = sel.max();
+            last = sel.min();
+            break;
         case InsertMode::Replace:
-        {
-            Kakoune::erase(buffer, sel);
-            first = last = sel.min();
+            first = last = Kakoune::erase(buffer, sel).coord();
             break;
-        }
         case InsertMode::Append:
-        {
             first = sel.min();
-            last  = sel.max();
+            last = sel.max();
             // special case for end of lines, append to current line instead
             if (last.column != buffer[last.line].length() - 1)
                 last = buffer.char_next(last);
             break;
-        }
 
         case InsertMode::OpenLineBelow:
         case InsertMode::AppendAtLineEnd:
-            first = BufferCoord{sel.max().line, buffer[sel.max().line].length() - 1};
-            last  = first;
+            first = last = BufferCoord{sel.max().line, buffer[sel.max().line].length() - 1};
             break;
 
         case InsertMode::OpenLineAbove:
@@ -540,30 +525,32 @@ IncrementalInserter::~IncrementalInserter()
 
 void IncrementalInserter::insert(String content)
 {
-    Buffer& buffer = m_editor.buffer();
+    auto& buffer = m_editor.buffer();
     for (auto& sel : m_editor.m_selections)
     {
         m_editor.filters()(buffer, sel, content);
-        buffer.insert(sel.last(), content);
+        buffer.insert(buffer.iterator_at(sel.last()), content);
     }
 }
 
 void IncrementalInserter::insert(const memoryview<String>& strings)
 {
+    auto& buffer = m_editor.buffer();
     for (size_t i = 0; i < m_editor.m_selections.size(); ++i)
     {
         size_t index = std::min(i, strings.size()-1);
-        m_editor.buffer().insert(m_editor.m_selections[i].last(),
-                                 strings[index]);
+        buffer.insert(buffer.iterator_at(m_editor.m_selections[i].last()),
+                      strings[index]);
     }
 }
 
 void IncrementalInserter::erase()
 {
+    auto& buffer = m_editor.buffer();
     for (auto& sel : m_editor.m_selections)
     {
-        BufferCoord pos = sel.last();
-        m_editor.buffer().erase(m_editor.buffer().char_prev(pos), pos);
+        auto pos = buffer.iterator_at(sel.last());
+        buffer.erase(pos-1, pos);
     }
 }
 
diff --git a/src/filters.cc b/src/filters.cc
index 61d98bca..02be6767 100644
--- a/src/filters.cc
+++ b/src/filters.cc
@@ -31,7 +31,7 @@ void cleanup_whitespaces(Buffer& buffer, Selection& selection, String& content)
             --whitespace_start;
         ++whitespace_start;
         if (whitespace_start != position)
-            buffer.erase(whitespace_start.coord(), position.coord());
+            buffer.erase(whitespace_start, position);
     }
 }
 
@@ -81,10 +81,10 @@ struct RegexFilter
                 {
                     String suffix(it+1, content.end());
                     content = String(content.begin(), it-1);
+                    buffer.insert(position, suffix);
 
                     auto& first = selection.first();
                     auto& last = selection.last();
-                    buffer.insert(last, suffix);
                     if (first == last)
                         first = buffer.advance(first, -suffix.length());
                     last = buffer.advance(last, -suffix.length());
diff --git a/src/input_handler.cc b/src/input_handler.cc
index 6dc74390..283b86ea 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -613,9 +613,8 @@ public:
             if (offset >= beg_offset and offset + end_offset < buffer_len and
                 std::equal(pos - beg_offset, pos, begin))
             {
-                auto beg = buffer.advance(sel.last(), -beg_offset);
-                buffer.erase(beg, buffer.advance(sel.last(), end_offset));
-                buffer.insert(beg, candidate);
+                pos = buffer.erase(pos - beg_offset, pos + end_offset);
+                buffer.insert(pos, candidate);
             }
         }
 
diff --git a/src/normal.cc b/src/normal.cc
index a0fba585..fb5306e7 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -474,9 +474,9 @@ void join_select_spaces(Context& context)
         SelectionList res = select_all_matches(buffer, sel, Regex{"(\n\\h*)+"});
         // remove last end of line if selected
         kak_assert(std::is_sorted(res.begin(), res.end(),
-              [](const Selection& lhs, const Selection& rhs)
-              { return lhs.min() < rhs.min(); }));
-        if (not res.empty() and buffer.is_end(buffer.char_next(res.back().max())))
+                   [](const Selection& lhs, const Selection& rhs)
+                   { return lhs.min() < rhs.min(); }));
+        if (not res.empty() and res.back().max() == buffer.back_coord())
             res.pop_back();
         return res;
     });
@@ -713,7 +713,7 @@ void align(Context& context)
     for (auto& sel : selections)
     {
         CharCount padding = max_col - get_column(sel.last());
-        buffer.insert(sel.last(), String{ ' ', padding });
+        buffer.insert(buffer.iterator_at(sel.last()), String{ ' ', padding });
     }
 }
 
diff --git a/src/selection.hh b/src/selection.hh
index c7e5e2c3..fb5f20dd 100644
--- a/src/selection.hh
+++ b/src/selection.hh
@@ -45,9 +45,10 @@ inline String content(const Buffer& buffer, const Range& range)
     return buffer.string(range.min(), buffer.char_next(range.max()));
 }
 
-inline void erase(Buffer& buffer, const Range& range)
+inline BufferIterator erase(Buffer& buffer, const Range& range)
 {
-    return buffer.erase(range.min(), buffer.char_next(range.max()));
+    return buffer.erase(buffer.iterator_at(range.min()),
+                        utf8::next(buffer.iterator_at(range.max())));
 }
 
 using CaptureList = std::vector<String>;
diff --git a/src/unit_tests.cc b/src/unit_tests.cc
index 52f11ea1..00f54eb3 100644
--- a/src/unit_tests.cc
+++ b/src/unit_tests.cc
@@ -13,16 +13,16 @@ void test_buffer()
     Buffer buffer("test", Buffer::Flags::None, { "allo ?\n", "mais que fais la police\n",  " hein ?\n", " youpi\n" });
     kak_assert(buffer.line_count() == 4);
 
-    BufferCoord pos = {0,0};
-    kak_assert(buffer.byte_at(pos) == 'a');
-    pos = buffer.advance(pos, 6);
-    kak_assert(pos == BufferCoord{0 COMMA 6});
-    pos = buffer.next(pos);
-    kak_assert(pos == BufferCoord{1 COMMA 0});
-    pos = buffer.prev(pos);
-    kak_assert(pos == BufferCoord{0 COMMA 6});
-    pos = buffer.advance(pos, 1);
-    kak_assert(pos == BufferCoord{1 COMMA 0});
+    BufferIterator pos = buffer.begin();
+    kak_assert(*pos == 'a');
+    pos += 6;
+    kak_assert(pos.coord() == BufferCoord{0 COMMA 6});
+    ++pos;
+    kak_assert(pos.coord() == BufferCoord{1 COMMA 0});
+    --pos;
+    kak_assert(pos.coord() == BufferCoord{0 COMMA 6});
+    pos += 1;
+    kak_assert(pos.coord() == BufferCoord{1 COMMA 0});
     buffer.insert(pos, "tchou kanaky\n");
     kak_assert(buffer.line_count() == 5);
 
@@ -30,17 +30,17 @@ void test_buffer()
     kak_assert(str == "youpi");
 
     // check insert at end behaviour: auto add end of line if necessary
-    pos = buffer.back_coord();
+    pos = buffer.end()-1;
     buffer.insert(pos, "tchou");
-    kak_assert(buffer.string(pos, buffer.end_coord()) == "tchou\n");
+    kak_assert(buffer.string(pos.coord(), buffer.end_coord()) == "tchou\n");
 
-    pos = buffer.back_coord();
-    buffer.insert(buffer.end_coord(), "kanaky\n");
-    kak_assert(buffer.string(buffer.next(pos), buffer.end_coord()) == "kanaky\n");
+    pos = buffer.end()-1;
+    buffer.insert(buffer.end(), "kanaky\n");
+    kak_assert(buffer.string((pos+1).coord(), buffer.end_coord()) == "kanaky\n");
 
     buffer.commit_undo_group();
-    buffer.erase(buffer.next(pos), buffer.end_coord());
-    buffer.insert(buffer.end_coord(), "mutch\n");
+    buffer.erase(pos+1, buffer.end());
+    buffer.insert(buffer.end(), "mutch\n");
     buffer.commit_undo_group();
     buffer.undo();
     kak_assert(buffer.string(buffer.advance(buffer.end_coord(), -7), buffer.end_coord()) == "kanaky\n");