Use vim-range style (1-index based) when possible (#1841)

https://github.com/nvim-treesitter/nvim-treesitter/pull/1829
half fixed incremental selection for the vim parser,
but other bugs still remain (infinite selection and skip selecting the
root node).

Problems can be replicated with these two files:

(missing selecting the root node)

```vim
set scrolloff=7
set scrolloff=7
```

(infinite loop)

```vim
set scrolloff=7
```

The main problem is that we try to map
the current selection range to a TS range,
but the TS range of a node could include the EOL/EOL marks
so it's impossible to know when to change the vim range
to match the TS range, is more easy to transform the
TS range to a vim range and do the comparison.

lua/nvim-treesitter/incremental_selection.lua

@@ -17,9 +17,9 @@ function M.init_selection()
   ts_utils.update_selection(buf, node)
 end
 
---- Get a ts compatible range of the current visual selection.
+--- Get the range of the current visual selection.
 --
--- The range of ts nodes start with 0 and the ending range is exclusive.
+-- The range start with 1 and the ending is inclusive.
 local function visual_selection_range()
   local _, csrow, cscol, _ = unpack(vim.fn.getpos "'<")
   local _, cerow, cecol, _ = unpack(vim.fn.getpos "'>")
@@ -27,33 +27,23 @@ local function visual_selection_range()
   local start_row, start_col, end_row, end_col
 
   if csrow < cerow or (csrow == cerow and cscol <= cecol) then
-    start_row = csrow - 1
-    start_col = cscol - 1
-    end_row = cerow - 1
+    start_row = csrow
+    start_col = cscol
+    end_row = cerow
     end_col = cecol
   else
-    start_row = cerow - 1
-    start_col = cecol - 1
-    end_row = csrow - 1
+    start_row = cerow
+    start_col = cecol
+    end_row = csrow
     end_col = cscol
   end
 
-  -- The last char in ts is equivalent to the EOF in another line.
-  local last_row = vim.fn.line "$"
-  local last_col = vim.fn.col { last_row, "$" }
-  last_row = last_row - 1
-  last_col = last_col - 1
-  if end_row == last_row and end_col == last_col then
-    end_row = end_row + 1
-    end_col = 0
-  end
-
   return start_row, start_col, end_row, end_col
 end
 
 local function range_matches(node)
   local csrow, cscol, cerow, cecol = visual_selection_range()
-  local srow, scol, erow, ecol = node:range()
+  local srow, scol, erow, ecol = ts_utils.get_vim_range { node:range() }
   return srow == csrow and scol == cscol and erow == cerow and ecol == cecol
 end
 
@@ -66,7 +56,7 @@ local function select_incremental(get_parent)
     -- Initialize incremental selection with current selection
     if not nodes or #nodes == 0 or not range_matches(nodes[#nodes]) then
       local root = parsers.get_parser():parse()[1]:root()
-      local node = root:named_descendant_for_range(csrow, cscol, cerow, cecol)
+      local node = root:named_descendant_for_range(csrow - 1, cscol - 1, cerow - 1, cecol)
       ts_utils.update_selection(buf, node)
       if nodes and #nodes > 0 then
         table.insert(selections[buf], node)
@@ -84,14 +74,14 @@ local function select_incremental(get_parent)
         -- Keep searching in the main tree
         -- TODO: we should search on the parent tree of the current node.
         local root = parsers.get_parser():parse()[1]:root()
-        parent = root:named_descendant_for_range(csrow, cscol, cerow, cecol)
-        if not parent or parent == node then
+        parent = root:named_descendant_for_range(csrow - 1, cscol - 1, cerow - 1, cecol)
+        if not parent or root == node or parent == node then
           ts_utils.update_selection(buf, node)
           return
         end
       end
       node = parent
-      local srow, scol, erow, ecol = node:range()
+      local srow, scol, erow, ecol = ts_utils.get_vim_range { node:range() }
       local same_range = (srow == csrow and scol == cscol and erow == cerow and ecol == cecol)
       if not same_range then
         table.insert(selections[buf], node)

lua/nvim-treesitter/ts_utils.lua

@@ -175,6 +175,29 @@ function M.highlight_node(node, buf, hl_namespace, hl_group)
   M.highlight_range({ node:range() }, buf, hl_namespace, hl_group)
 end
 
+--- Get a compatible vim range (1 index based) from a TS node range.
+--
+-- TS nodes start with 0 and the end col is ending exclusive.
+-- They also treat a EOF/EOL char as a char ending in the first
+-- col of the next row.
+function M.get_vim_range(range, buf)
+  local srow, scol, erow, ecol = unpack(range)
+  srow = srow + 1
+  scol = scol + 1
+  erow = erow + 1
+
+  if ecol == 0 then
+    -- Use the value of the last col of the previous row instead.
+    erow = erow - 1
+    if not buf or buf == 0 then
+      ecol = vim.fn.col { erow, "$" } - 1
+    else
+      ecol = #api.nvim_buf_get_lines(buf, erow - 1, erow, false)[1]
+    end
+  end
+  return srow, scol, erow, ecol
+end
+
 function M.highlight_range(range, buf, hl_namespace, hl_group)
   local start_row, start_col, end_row, end_col = unpack(range)
   vim.highlight.range(buf, hl_namespace, hl_group, { start_row, start_col }, { end_row, end_col })
@@ -185,17 +208,7 @@ end
 --   "blockwise" or "<C-v>" (as a string with 5 characters or a single character)
 function M.update_selection(buf, node, selection_mode)
   selection_mode = selection_mode or "charwise"
-  local start_row, start_col, end_row, end_col = M.get_node_range(node)
-
-  if end_row == vim.fn.line "$" then
-    end_col = #vim.fn.getline "$"
-  end
-
-  -- Convert to 1-based indices
-  start_row = start_row + 1
-  start_col = start_col + 1
-  end_row = end_row + 1
-  end_col = end_col + 1
+  local start_row, start_col, end_row, end_col = M.get_vim_range({ M.get_node_range(node) }, buf)
 
   vim.fn.setpos(".", { buf, start_row, start_col, 0 })
 
@@ -205,14 +218,7 @@ function M.update_selection(buf, node, selection_mode)
   ---- command to enter blockwise mode
   local mode_string = vim.api.nvim_replace_termcodes(v_table[selection_mode] or selection_mode, true, true, true)
   vim.cmd("normal! " .. mode_string)
-
-  -- Convert exclusive end position to inclusive
-  if end_col == 1 then
-    local previous_col = vim.fn.col { end_row - 1, "$" } - 1
-    vim.fn.setpos(".", { buf, end_row - 1, previous_col, 0 })
-  else
-    vim.fn.setpos(".", { buf, end_row, end_col - 1, 0 })
-  end
+  vim.fn.setpos(".", { buf, end_row, end_col, 0 })
 end
 
 -- Byte length of node range