From 11d9b607668d56c8deaf9062d48d9ce7aa6f5928 Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Tue, 13 May 2014 23:22:54 +0100
Subject: [PATCH] Make it harder to have an invalid SelectionList

---
 src/dynamic_selection_list.cc |  6 ++---
 src/normal.cc                 | 47 +++++++++++++++++------------------
 src/selection.cc              | 28 ++++++++++-----------
 src/selection.hh              | 16 +++++++++---
 src/selectors.cc              |  6 ++---
 5 files changed, 53 insertions(+), 50 deletions(-)

diff --git a/src/dynamic_selection_list.cc b/src/dynamic_selection_list.cc
index 4087bb0c..f49b36c7 100644
--- a/src/dynamic_selection_list.cc
+++ b/src/dynamic_selection_list.cc
@@ -19,14 +19,12 @@ DynamicSelectionList& DynamicSelectionList::operator=(SelectionList selections)
 
 void DynamicSelectionList::on_insert(const Buffer& buffer, ByteCoord begin, ByteCoord end, bool at_end)
 {
-    update_insert(begin, end, at_end);
-    set_timestamp(buffer.timestamp());
+    update();
 }
 
 void DynamicSelectionList::on_erase(const Buffer& buffer, ByteCoord begin, ByteCoord end, bool at_end)
 {
-    update_erase(begin, end, at_end);
-    set_timestamp(buffer.timestamp());
+    update();
 }
 
 }
diff --git a/src/normal.cc b/src/normal.cc
index 7ac51ad5..15068fce 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -739,7 +739,7 @@ void split_lines(Context& context, int)
 {
     auto& selections = context.selections();
     auto& buffer = context.buffer();
-    SelectionList res(context.buffer());
+    std::vector<Selection> res;
     for (auto& sel : selections)
     {
         if (sel.anchor().line == sel.cursor().line)
@@ -754,14 +754,13 @@ void split_lines(Context& context, int)
             res.push_back({line, {line, buffer[line].length()-1}});
         res.push_back({max.line, max});
     }
-    res.set_main_index(res.size() - 1);
     selections = std::move(res);
 }
 
 void join_select_spaces(Context& context, int)
 {
     auto& buffer = context.buffer();
-    SelectionList selections(buffer);
+    std::vector<Selection> selections;
     for (auto& sel : context.selections())
     {
         for (LineCount line = sel.min().line; line <= sel.max().line; ++line)
@@ -776,7 +775,6 @@ void join_select_spaces(Context& context, int)
     }
     if (selections.empty())
         return;
-    selections.sort_and_merge_overlapping();
     context.selections() = selections;
     ScopedEdition edition(context);
     insert<InsertMode::Replace>(buffer, context.selections(), " ");
@@ -801,7 +799,7 @@ void keep(Context& context, int)
         if (ex.empty())
             return;
         const Buffer& buffer = context.buffer();
-        SelectionList keep(buffer);
+        std::vector<Selection> keep;
         for (auto& sel : context.selections())
         {
             if (boost::regex_search(buffer.iterator_at(sel.min()),
@@ -823,7 +821,7 @@ void keep_pipe(Context& context, int)
                 return;
             const Buffer& buffer = context.buffer();
             auto& shell_manager = ShellManager::instance();
-            SelectionList keep(buffer);
+            std::vector<Selection> keep;
             for (auto& sel : context.selections())
             {
                 int status = 0;
@@ -844,7 +842,7 @@ void indent(Context& context, int)
     String indent = indent_width == 0 ? "\t" : String{' ', indent_width};
 
     auto& buffer = context.buffer();
-    SelectionList sels(buffer);
+    std::vector<Selection> sels;
     for (auto& sel : context.selections())
     {
         for (auto line = sel.min().line; line < sel.max().line+1; ++line)
@@ -856,7 +854,8 @@ void indent(Context& context, int)
     if (not sels.empty())
     {
         ScopedEdition edition(context);
-        insert<InsertMode::Insert>(buffer, sels, indent);
+        SelectionList selections{buffer, std::move(sels)};
+        insert<InsertMode::Insert>(buffer, selections, indent);
     }
 }
 
@@ -869,7 +868,7 @@ void deindent(Context& context, int)
         indent_width = tabstop;
 
     auto& buffer = context.buffer();
-    SelectionList sels(buffer);
+    std::vector<Selection> sels;
     for (auto& sel : context.selections())
     {
         for (auto line = sel.min().line; line < sel.max().line+1; ++line)
@@ -900,7 +899,8 @@ void deindent(Context& context, int)
     if (not sels.empty())
     {
         ScopedEdition edition(context);
-        erase(context.buffer(), sels);
+        SelectionList selections{context.buffer(), std::move(sels)};
+        erase(context.buffer(), selections);
     }
 }
 
@@ -1238,16 +1238,16 @@ void spaces_to_tabs(Context& context, int ts)
     }
 }
 
-static SelectionList compute_modified_ranges(const Buffer& buffer, size_t timestamp)
+static boost::optional<SelectionList> compute_modified_ranges(const Buffer& buffer, size_t timestamp)
 {
-    SelectionList ranges(buffer);
+    std::vector<Selection> ranges;
     for (auto& change : buffer.changes_since(timestamp))
     {
         const ByteCoord& begin = change.begin;
         const ByteCoord& end = change.end;
         if (change.type == Buffer::Change::Insert)
         {
-            ranges.update_insert(begin, end, change.at_end);
+            update_insert(ranges, begin, end, change.at_end);
             auto it = std::upper_bound(ranges.begin(), ranges.end(), begin,
                                        [](ByteCoord c, const Selection& sel)
                                        { return c < sel.min(); });
@@ -1255,7 +1255,7 @@ static SelectionList compute_modified_ranges(const Buffer& buffer, size_t timest
         }
         else
         {
-            ranges.update_erase(begin, end, change.at_end);
+            update_erase(ranges, begin, end, change.at_end);
             auto pos = begin;
             if (change.at_end)
                 pos = begin.column ? ByteCoord{begin.line, begin.column - 1}
@@ -1267,23 +1267,22 @@ static SelectionList compute_modified_ranges(const Buffer& buffer, size_t timest
         }
     }
     if (ranges.empty())
-        return ranges;
+        return {};
 
-    ranges.set_timestamp(buffer.timestamp());
-    ranges.set_main_index(ranges.size() - 1);
+    SelectionList result{buffer, std::move(ranges)};
 
     auto touches = [&](const Selection& lhs, const Selection& rhs) {
         return lhs.min() <= rhs.min() ? buffer.char_next(lhs.max()) >= rhs.min()
                                       : lhs.min() <= buffer.char_next(rhs.max());
     };
-    ranges.merge_overlapping(touches);
+    result.merge_overlapping(touches);
 
-    for (auto& sel : ranges)
+    for (auto& sel : result)
     {
         if (sel.anchor() != sel.cursor())
             sel.cursor() = buffer.char_prev(sel.cursor());
     }
-    return ranges;
+    return result;
 }
 
 void undo(Context& context, int)
@@ -1294,8 +1293,8 @@ void undo(Context& context, int)
     if (res)
     {
         auto ranges = compute_modified_ranges(buffer, timestamp);
-        if (not ranges.empty())
-            context.selections() = std::move(ranges);
+        if (ranges)
+            context.selections() = std::move(*ranges);
     }
     else if (not res)
         context.print_status({ "nothing left to undo", get_color("Information") });
@@ -1310,8 +1309,8 @@ void redo(Context& context, int)
     if (res)
     {
         auto ranges = compute_modified_ranges(buffer, timestamp);
-        if (not ranges.empty())
-            context.selections() = std::move(ranges);
+        if (ranges)
+            context.selections() = std::move(*ranges);
     }
 
     else if (not res)
diff --git a/src/selection.cc b/src/selection.cc
index 895c1f96..3dee22ec 100644
--- a/src/selection.cc
+++ b/src/selection.cc
@@ -18,7 +18,7 @@ namespace
 {
 
 template<template <bool, bool> class UpdateFunc>
-void on_buffer_change(SelectionList& sels,
+void on_buffer_change(std::vector<Selection>& sels,
                       ByteCoord begin, ByteCoord end, bool at_end, LineCount end_line)
 {
     auto update_beg = std::lower_bound(sels.begin(), sels.end(), begin,
@@ -101,14 +101,11 @@ struct UpdateErase
 
 }
 
-SelectionList::SelectionList(const Buffer& buffer)
-    : m_buffer(&buffer), m_timestamp(buffer.timestamp())
-{
-}
-
 SelectionList::SelectionList(const Buffer& buffer, Selection s, size_t timestamp)
     : m_buffer(&buffer), m_selections({ s }), m_timestamp(timestamp)
-{}
+{
+    check_invariant();
+}
 
 SelectionList::SelectionList(const Buffer& buffer, Selection s)
     : SelectionList(buffer, s, buffer.timestamp())
@@ -116,20 +113,23 @@ SelectionList::SelectionList(const Buffer& buffer, Selection s)
 
 SelectionList::SelectionList(const Buffer& buffer, std::vector<Selection> s, size_t timestamp)
     : m_buffer(&buffer), m_selections(std::move(s)), m_timestamp(timestamp)
-{}
+{
+    kak_assert(size() > 0);
+    check_invariant();
+}
 
 SelectionList::SelectionList(const Buffer& buffer, std::vector<Selection> s)
     : SelectionList(buffer, std::move(s), buffer.timestamp())
 {}
 
-void SelectionList::update_insert(ByteCoord begin, ByteCoord end, bool at_end)
+void update_insert(std::vector<Selection>& sels, ByteCoord begin, ByteCoord end, bool at_end)
 {
-    on_buffer_change<UpdateInsert>(*this, begin, end, at_end, begin.line);
+    on_buffer_change<UpdateInsert>(sels, begin, end, at_end, begin.line);
 }
 
-void SelectionList::update_erase(ByteCoord begin, ByteCoord end, bool at_end)
+void update_erase(std::vector<Selection>& sels, ByteCoord begin, ByteCoord end, bool at_end)
 {
-    on_buffer_change<UpdateErase>(*this, begin, end, at_end, end.line);
+    on_buffer_change<UpdateErase>(sels, begin, end, at_end, end.line);
 }
 
 void SelectionList::update()
@@ -137,9 +137,9 @@ void SelectionList::update()
     for (auto& change : m_buffer->changes_since(m_timestamp))
     {
         if (change.type == Buffer::Change::Insert)
-            update_insert(change.begin, change.end, change.at_end);
+            update_insert(m_selections, change.begin, change.end, change.at_end);
         else
-            update_erase(change.begin, change.end, change.at_end);
+            update_erase(m_selections, change.begin, change.end, change.at_end);
     }
     m_timestamp = m_buffer->timestamp();
 
diff --git a/src/selection.hh b/src/selection.hh
index 9b3f747a..f8727b90 100644
--- a/src/selection.hh
+++ b/src/selection.hh
@@ -57,15 +57,11 @@ static bool compare_selections(const Selection& lhs, const Selection& rhs)
 
 struct SelectionList
 {
-    SelectionList(const Buffer& buffer);
     SelectionList(const Buffer& buffer, Selection s);
     SelectionList(const Buffer& buffer, Selection s, size_t timestamp);
     SelectionList(const Buffer& buffer, std::vector<Selection> s);
     SelectionList(const Buffer& buffer, std::vector<Selection> s, size_t timestamp);
 
-    void update_insert(ByteCoord begin, ByteCoord end, bool at_end);
-    void update_erase(ByteCoord begin, ByteCoord end, bool at_end);
-
     void update();
 
     void check_invariant() const;
@@ -83,6 +79,15 @@ struct SelectionList
     Selection& operator[](size_t i) { return m_selections[i]; }
     const Selection& operator[](size_t i) const { return m_selections[i]; }
 
+    SelectionList& operator=(std::vector<Selection> list)
+    {
+        m_selections = std::move(list);
+        m_main = size()-1;
+        sort_and_merge_overlapping();
+        check_invariant();
+        return *this;
+    }
+
     using iterator = std::vector<Selection>::iterator;
     iterator begin() { return m_selections.begin(); }
     iterator end() { return m_selections.end(); }
@@ -148,6 +153,9 @@ private:
     size_t m_timestamp;
 };
 
+void update_insert(std::vector<Selection>& sels, ByteCoord begin, ByteCoord end, bool at_end);
+void update_erase(std::vector<Selection>& sels, ByteCoord begin, ByteCoord end, bool at_end);
+
 }
 
 #endif // selection_hh_INCLUDED
diff --git a/src/selectors.cc b/src/selectors.cc
index 40db98c9..2e823d9d 100644
--- a/src/selectors.cc
+++ b/src/selectors.cc
@@ -437,7 +437,7 @@ void select_whole_buffer(const Buffer& buffer, SelectionList& selections)
 void select_all_matches(const Buffer& buffer, SelectionList& selections,
                         const Regex& regex)
 {
-    SelectionList result(buffer);
+    std::vector<Selection> result;
     for (auto& sel : selections)
     {
         auto sel_end = utf8::next(buffer.iterator_at(sel.max()));
@@ -463,14 +463,13 @@ void select_all_matches(const Buffer& buffer, SelectionList& selections,
     }
     if (result.empty())
         throw runtime_error("nothing selected");
-    result.set_main_index(result.size() - 1);
     selections = std::move(result);
 }
 
 void split_selections(const Buffer& buffer, SelectionList& selections,
                       const Regex& regex)
 {
-    SelectionList result(buffer);
+    std::vector<Selection> result;
     for (auto& sel : selections)
     {
         auto begin = buffer.iterator_at(sel.min());
@@ -489,7 +488,6 @@ void split_selections(const Buffer& buffer, SelectionList& selections,
         if (begin.coord() <= sel.max())
             result.push_back({ begin.coord(), sel.max() });
     }
-    result.set_main_index(result.size() - 1);
     selections = std::move(result);
 }