Remove Cursor and move line-tracking into Iterator

src/core/Buffer-Cursor.cc

@@ -1,184 +0,0 @@
-#include "Buffer.h"
-
-bool Buffer::Cursor::is_start_of_line()
-{
-    Iterator i2 = m_iterator;
-    if (!i2.check_go_back())
-    {
-        /* Iterator cannot go backwards so it is at beginning of buffer. */
-        return true;
-    }
-    return *i2 == '\n';
-}
-
-bool Buffer::Cursor::is_end_of_line(bool allow_eol)
-{
-    if ((*m_iterator == '\n') || (!m_iterator.valid()))
-    {
-        return true;
-    }
-    if (!allow_eol)
-    {
-        Iterator i2 = m_iterator;
-        i2.go_forward();
-        if (*i2 == '\n')
-        {
-            return true;
-        }
-    }
-    return false;
-}
-
-bool Buffer::Cursor::go_start_of_line()
-{
-    bool moved = false;
-    Iterator i2 = m_iterator;
-    for (;;)
-    {
-        i2.go_back();
-        if (i2.valid() && (*i2 != '\n'))
-        {
-            moved = true;
-            m_iterator = i2;
-        }
-        else
-        {
-            break;
-        }
-    }
-    if (moved)
-    {
-        init_column();
-    }
-    return moved;
-}
-
-bool Buffer::Cursor::go_end_of_line(bool allow_eol)
-{
-    bool moved = false;
-    if (go_right(allow_eol))
-    {
-        moved = true;
-    }
-    while (go_right(allow_eol))
-    {
-        ;
-    }
-    return moved;
-}
-
-bool Buffer::Cursor::go_left()
-{
-    if (!is_start_of_line())
-    {
-        uint32_t chr = *m_iterator;
-        if (m_iterator.check_go_back())
-        {
-            if (chr == '\t')
-            {
-                calculate_column();
-            }
-            else
-            {
-                /* TODO: handle multi-column characters */
-                m_column--;
-            }
-            return true;
-        }
-    }
-    return false;
-}
-
-bool Buffer::Cursor::go_right(bool allow_eol)
-{
-    if (!is_end_of_line(allow_eol))
-    {
-        if (m_iterator.check_go_forward())
-        {
-            uint32_t chr = *m_iterator;
-            if (chr == '\t')
-            {
-                uint8_t tabstop = m_iterator.buffer()->tabstop();
-                m_column += tabstop - (m_column + 1u) % tabstop;
-            }
-            else
-            {
-                /* TODO: handle multi-column characters */
-                m_column++;
-            }
-            return true;
-        }
-    }
-    return false;
-}
-
-bool Buffer::Cursor::go_up(size_t target_column)
-{
-    Buffer::Cursor c2 = *this;
-    c2.go_start_of_line();
-    if (!c2.m_iterator.check_go_back())
-    {
-        return false;
-    }
-    c2.go_start_of_line();
-    *this = c2;
-    m_line--;
-    m_column = 0u;
-    forward_to_column(target_column);
-    return true;
-}
-
-bool Buffer::Cursor::go_down(size_t target_column)
-{
-    Buffer::Cursor c2 = *this;
-    c2.go_end_of_line(true);
-    if (!c2.m_iterator.check_go_forward())
-    {
-        return false;
-    }
-    *this = c2;
-    m_line++;
-    m_column = 0u;
-    forward_to_column(target_column);
-    return true;
-}
-
-void Buffer::Cursor::init_column()
-{
-    if (*m_iterator == '\t')
-    {
-        m_column = m_iterator.buffer()->tabstop() - 1u;
-    }
-    else
-    {
-        m_column = 0u;
-    }
-}
-
-void Buffer::Cursor::calculate_column()
-{
-    Buffer::Cursor tmp_cursor = *this;
-    tmp_cursor.go_start_of_line();
-    while (tmp_cursor < *this)
-    {
-        tmp_cursor.go_right(true);
-    }
-    m_column = tmp_cursor.m_column;
-}
-
-void Buffer::Cursor::forward_to_column(size_t target_column)
-{
-    int32_t diff = abs((int32_t)(target_column - m_column));
-    if (diff == 0)
-        return;
-    while (go_right(false))
-    {
-        int32_t new_diff = abs((int32_t)(target_column - m_column));
-        if (new_diff > diff)
-        {
-            go_left();
-            return;
-        }
-        diff = new_diff;
-    }
-}

src/core/Buffer-Iterator.cc

@@ -1,56 +1,186 @@
 #include "Buffer.h"
 
-void Buffer::Iterator::go_forward()
+bool Buffer::Iterator::is_start_of_line()
 {
     if (valid())
     {
-        m_offset += Encoding::num_bytes_in_code_point(m_buffer->encoding(), address());
-    }
-}
-
-bool Buffer::Iterator::check_go_forward()
-{
-    if (valid())
-    {
-        Buffer::Iterator i2 = *this;
-        i2.go_forward();
-        if (i2.valid())
+        if (m_offset == 0u)
+        {
+            return true;
+        }
+        const uint8_t * a = m_buffer->address(m_offset - 1u);
+        a = Encoding::beginning_of_code_point(m_buffer->encoding(), a);
+        if (Encoding::decode(m_buffer->encoding(), a) == '\n')
         {
-            m_offset = i2.m_offset;
             return true;
         }
     }
     return false;
 }
 
-void Buffer::Iterator::go_back()
+bool Buffer::Iterator::is_end_of_line(bool eol_only)
 {
     if (valid())
+    {
+        if (**this == '\n')
+        {
+            return true;
+        }
+        if (!eol_only)
+        {
+            return false;
+        }
+        Iterator i2 = *this;
+        if (!i2.go_forward())
+        {
+            return false;
+        }
+        if (*i2 == '\n')
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool Buffer::Iterator::go_back()
+{
+    if (valid() || (m_offset == m_buffer->size()))
     {
         if (m_offset == 0u)
         {
-            m_offset = 0xFFFFFFFFu;
+            m_offset = (size_t)-1;
         }
         else
         {
             const uint8_t * a = m_buffer->address(m_offset - 1u);
             const uint8_t * beginning_of_code_point = Encoding::beginning_of_code_point(m_buffer->encoding(), a);
             m_offset -= ((a - beginning_of_code_point) + 1u);
+            if (Encoding::decode(m_buffer->encoding(), address()) == '\n')
+            {
+                m_line--;
+            }
         }
+        return true;
     }
+    return false;
 }
 
-bool Buffer::Iterator::check_go_back()
+bool Buffer::Iterator::go_forward()
 {
     if (valid())
     {
-        Buffer::Iterator i2 = *this;
-        i2.go_back();
-        if (i2.valid())
+        uint8_t size;
+        uint32_t c = Encoding::decode(m_buffer->encoding(), address(), &size);
+        m_offset += size;
+        if (c == '\n')
         {
-            m_offset = i2.m_offset;
-            return true;
+            m_line++;
+        }
+        return true;
+    }
+    else if (m_offset == (size_t)-1)
+    {
+        m_offset = 0u;
+        return true;
+    }
+    return false;
+}
+
+bool Buffer::Iterator::go_start_of_line()
+{
+    bool moved = false;
+    Iterator i2 = *this;
+    i2.go_back();
+    while (i2.valid() && (*i2 != '\n'))
+    {
+        m_offset = i2.m_offset;
+        moved = true;
+        i2.go_back();
+    }
+    return moved;
+}
+
+bool Buffer::Iterator::go_end_of_line(bool allow_eol)
+{
+    bool moved = false;
+    if (go_right_in_line(allow_eol))
+    {
+        moved = true;
+    }
+    while (go_right_in_line(allow_eol))
+    {
+        ;
+    }
+    return moved;
+}
+
+bool Buffer::Iterator::go_left_in_line()
+{
+    bool moved = false;
+    Iterator i2 = *this;
+    i2.go_back();
+    if (i2.valid() && (*i2 != '\n'))
+    {
+        m_offset = i2.m_offset;
+        moved = true;
+    }
+    return moved;
+}
+
+bool Buffer::Iterator::go_right_in_line(bool allow_eol)
+{
+    if (valid() && (**this != '\n'))
+    {
+        if (allow_eol)
+        {
+            return go_forward();
+        }
+        else
+        {
+            Iterator i2 = *this;
+            i2.go_forward();
+            if (i2.valid() && (*i2 != '\n'))
+            {
+                m_offset = i2.m_offset;
+                return true;
+            }
         }
     }
     return false;
 }
+
+bool Buffer::Iterator::go_previous_line()
+{
+    uint_fast8_t eol_count = 0u;
+    Iterator i2 = *this;
+    i2.go_back();
+    size_t new_offset = 0u;
+    while (i2.valid() && ((*i2 != '\n') || (++eol_count < 2u)))
+    {
+        new_offset = i2.m_offset;
+        i2.go_back();
+    }
+    if (eol_count == 2u)
+    {
+        m_offset = new_offset;
+        return true;
+    }
+    return false;
+}
+
+bool Buffer::Iterator::go_next_line()
+{
+    Iterator i2 = *this;
+    while (i2.valid() && (*i2 != '\n'))
+    {
+        i2.go_forward();
+    }
+    i2.go_forward();
+    if (i2.valid())
+    {
+        *this = i2;
+        return true;
+    }
+    return false;
+}

src/core/Buffer.cc

@@ -112,14 +112,14 @@ bool Buffer::write_to_file(const char * filename)
 
     m_gap_buffer->compact();
 
-    Cursor start_of_line(this);
+    Iterator start_of_line(this);
     size_t bytes_written = 0u;
 
     while (start_of_line.valid())
     {
-        Cursor cursor = start_of_line;
-        cursor.go_end_of_line(true);
-        size_t len = cursor.address() - start_of_line.address();
+        Iterator iterator = start_of_line;
+        iterator.go_end_of_line(true);
+        size_t len = iterator.address() - start_of_line.address();
         if (len > 0u)
         {
             if (!file.write(start_of_line.address(), len))
@@ -128,7 +128,7 @@ bool Buffer::write_to_file(const char * filename)
             }
             bytes_written += len;
         }
-        bool moved_down = cursor.go_down(0u);
+        bool moved_down = iterator.go_next_line();
         if (moved_down || m_eol_at_eof)
         {
             if (!file.write(LineEndings::spans[m_line_endings]))
@@ -141,7 +141,7 @@ bool Buffer::write_to_file(const char * filename)
         {
             break;
         }
-        start_of_line = cursor;
+        start_of_line = iterator;
     }
 
     return true;

src/core/Buffer.h

@@ -17,15 +17,27 @@ public:
         {
             m_buffer = buffer;
             m_offset = 0u;
+            m_line = 0u;
         }
         bool valid() const
         {
             return m_offset < m_buffer->size();
         }
-        void go_forward();
-        bool check_go_forward();
-        void go_back();
-        bool check_go_back();
+        bool is_start_of_line();
+        bool is_end_of_line(bool eol_only);
+        bool go_back();
+        bool go_forward();
+        bool go_start_of_line();
+        bool go_end_of_line(bool allow_eol);
+        bool go_left_in_line();
+        bool go_right_in_line(bool allow_eol);
+        bool go_previous_line();
+        bool go_next_line();
+        void warp(ssize_t offset_offset, ssize_t line_offset)
+        {
+            m_offset += offset_offset;
+            m_line += line_offset;
+        }
         uint8_t * address() const
         {
             return m_buffer->address(m_offset);
@@ -41,58 +53,36 @@ public:
                 return 0xFFFFFFFFu;
             }
         }
+        bool operator==(const Iterator & other) const
+        {
+            return m_offset == other.m_offset;
+        }
+        bool operator!=(const Iterator & other) const
+        {
+            return m_offset != other.m_offset;
+        }
         bool operator<(const Iterator & other) const
         {
             return m_offset < other.m_offset;
         }
-        size_t offset() { return m_offset; }
-        void set_offset(size_t new_offset) { m_offset = new_offset; }
-        Buffer * buffer() const { return m_buffer; }
+        bool operator<=(const Iterator & other) const
+        {
+            return m_offset <= other.m_offset;
+        }
+        bool operator>(const Iterator & other) const
+        {
+            return m_offset > other.m_offset;
+        }
+        bool operator>=(const Iterator & other) const
+        {
+            return m_offset >= other.m_offset;
+        }
+        size_t line() const { return m_line; }
 
     protected:
         Buffer * m_buffer;
         size_t m_offset;
-    };
-
-    class Cursor
-    {
-    public:
-        Cursor(Buffer * buffer)
-            : m_iterator(buffer)
-        {
-            m_line = 0u;
-            init_column();
-        }
-        bool is_start_of_line();
-        bool is_end_of_line(bool allow_eol);
-        bool go_start_of_line();
-        bool go_end_of_line(bool allow_eol);
-        bool go_left();
-        bool go_right(bool allow_eol);
-        bool go_up(size_t target_column);
-        bool go_down(size_t target_column);
-        bool operator<(const Cursor & other) const
-        {
-            return m_iterator < other.m_iterator;
-        }
-        bool operator==(const Cursor & other) const
-        {
-            return (m_line == other.m_line) && (m_column == other.m_column);
-        }
-        uint32_t operator*() const { return *m_iterator; }
-        uint8_t * address() const { return m_iterator.address(); }
-        bool valid() const { return m_iterator.valid(); }
-        size_t line() const { return m_line; }
-        size_t column() const { return m_column; }
-        void calculate_column();
-
-    protected:
-        Iterator m_iterator;
         size_t m_line;
-        size_t m_column;
-
-        void init_column();
-        void forward_to_column(size_t target_column);
     };
 
     Buffer();
@@ -100,9 +90,9 @@ public:
     Buffer(const uint8_t * data, size_t data_length);
     bool write_to_file(const char * filename);
 
-    std::shared_ptr<Cursor> add_cursor()
+    std::shared_ptr<Iterator> add_iterator()
     {
-        return std::make_shared<Cursor>(this);
+        return std::make_shared<Iterator>(this);
     }
     auto get_string() { return m_gap_buffer->get_string(); }
     size_t size() const { return m_gap_buffer->size(); }