refacto/feat: better handling of parser updates

features:
- node_movement is moving between scopes.
- add selection initialization from normal mode
- add a decremental selection

improvements:
- attach to buffer to run tree parsing on change
- run state update on CursorMoved
- the buffer state is:
```
{
  cursor_pos = { row=row, col=col },
  current_node = node_under_cursor,
  selection = {
      range = nil, -- activates when starting a selection
      nodes = {} -- filling up when starting an incremental selection
  },
  parser = parser, -- parser for current buffer
}
```
- refacto all the modules reliant on parsing the tree, update the current nodes, get the current nodes...

fixes:
- fix has_parser to look for .so libraries
- fix should select the whole file when selection root in selection

14 files changed, 554 insertions, 332 deletions

diff --git a/README.md b/README.md
index afedbc400..2c5a3ce71 100644
--- a/README.md
+++ b/README.md
@@ -89,25 +89,27 @@ in your `init.vim`:
 lua <<EOF
 require'nvim-treesitter.configs'.setup {
     highlight = {
-        enable = true,                 -- false will disable the whole extension
-        disable = { 'c', 'rust' },     -- list of language that will be disabled
+        enable = true,                    -- false will disable the whole extension
+        disable = { 'c', 'rust' },        -- list of language that will be disabled
     },
-    incremental_selection = {             -- this enables incremental selection
+    incremental_selection = {
         enable = true,
         disable = { 'cpp', 'lua' },
         keymaps = {                       -- mappings for incremental selection (visual mappings)
-          node_incremental = "<leader>e", -- "grn" by default,
-          scope_incremental = "<leader>f" -- "grc" by default
+          init_selection = 'gnn',         -- maps in normal mode to init the node/scope selection
+          node_incremental = "grn",       -- increment to the upper named parent
+          scope_incremental = "grc",      -- increment to the upper scope (as defined in locals.scm)
+          scope_decremental = "grm",      -- decrement to the previous scope
         }
     },
-    node_movement = {                     -- this enables cursor movement in node hierarchy
+    node_movement = {                     -- allows cursor movement in node hierarchy
         enable = true,
         disable = { 'cpp', 'rust' },
-        keymaps = {                       -- mappings for node movement (normal mappings)
-          move_up = "<a-k>",              -- default is to move with alt key hold
-          move_down = "<a-j>",
-          move_left = "<a-h>",
-          move_right = "<a-l>",
+        keymaps = {                       -- mappings for scope movement (normal mappings)
+          parent_scope = "<a-k>",         -- default is to move with alt key hold
+          child_scope = "<a-j>",
+          next_scope = "<a-h>",
+          previous_scope = "<a-l>",
         }
     },
     ensure_installed = 'all' -- one of 'all', 'language', or a list of languages
@@ -134,7 +136,7 @@ Some of these features are :
   - [x] Incremental selection
   - [ ] Syntax based code folding
   - [x] Consistent syntax highlighting (the api is not quite stable yet)
-  - [x] Cursor movement in node hierachy
+  - [x] Cursor movement in scope hierachy
   - [x] Statusline indicator (`require'nvim-treesitter'.statusline(size)`)
 
 You can find the roadmap [here](https://github.com/nvim-treesitter/nvim-treesitter/projects/1).
diff --git a/doc/nvim-treesitter.txt b/doc/nvim-treesitter.txt
index 084936bad..9c66b0a57 100644
--- a/doc/nvim-treesitter.txt
+++ b/doc/nvim-treesitter.txt
@@ -31,25 +31,27 @@ By default, everything is disabled. To enable support for features, in your `ini
   lua <<EOF
   require'nvim-treesitter.configs'.setup {
     highlight = {
-        enable = true,                 -- false will disable the whole extension
-        disable = { 'c', 'rust' },     -- list of language that will be disabled
+        enable = true,                    -- false will disable the whole extension
+        disable = { 'c', 'rust' },        -- list of language that will be disabled
     },
-    incremental_selection = {             -- this enables incremental selection
+    incremental_selection = {
         enable = true,
         disable = { 'cpp', 'lua' },
         keymaps = {                       -- mappings for incremental selection (visual mappings)
-          node_incremental = "<leader>e", -- "grn" by default,
-          scope_incremental = "<leader>f" -- "grc" by default
+          init_selection = 'gnn',         -- maps in normal mode to init the node/scope selection
+          node_incremental = "grn",       -- increment to the upper named parent
+          scope_incremental = "grc",      -- increment to the upper scope (as defined in locals.scm)
+          scope_decremental = "grm",      -- decrement to the previous scope
         }
     },
     node_movement = {                           -- this cursor movement in node hierachy
         enable = true,
         disable = { 'cpp', 'rust' },
-        keymaps = {                       -- mappings for node movement (normal mappings)
-          move_up = "<a-k>",              -- default is to move with alt key hold
-          move_down = "<a-j>",
-          move_left = "<a-h>",
-          move_right = "<a-l>",
+        keymaps = {                       -- mappings for scope movement
+          parent_scope = "<a-k>",         -- default is to move with alt key hold
+          child_scope = "<a-j>",
+          next_scope = "<a-h>",
+          previous_scope = "<a-l>",
         }
     },
     ensure_installed = 'all' -- one of 'all', 'language', or a list of languages
diff --git a/lua/nvim-treesitter.lua b/lua/nvim-treesitter.lua
index 90b5468a3..5c0dfac75 100644
--- a/lua/nvim-treesitter.lua
+++ b/lua/nvim-treesitter.lua
@@ -1,15 +1,14 @@
 local api = vim.api
+
 local install = require'nvim-treesitter.install'
-local locals = require'nvim-treesitter.locals'
 local utils = require'nvim-treesitter.utils'
 local info = require'nvim-treesitter.info'
 local configs = require'nvim-treesitter.configs'
+local state = require'nvim-treesitter.state'
 
 local M = {}
 
--- This function sets up everythin needed for a given language
--- this is the main interface through the plugin
-function M.setup(lang)
+function M.setup()
   utils.setup_commands('install', install.commands)
   utils.setup_commands('info', info.commands)
   utils.setup_commands('configs', configs.commands)
@@ -18,33 +17,34 @@ function M.setup(lang)
     for _, mod in pairs(configs.available_modules()) do
       if configs.is_enabled(mod, ft) then
         local cmd = string.format("lua require'nvim-treesitter.%s'.attach()", mod)
-        api.nvim_command(string.format("autocmd FileType %s %s", ft, cmd))
+        api.nvim_command(string.format("autocmd NvimTreesitter FileType %s %s", ft, cmd))
       end
     end
+    local cmd = string.format("lua require'nvim-treesitter.state'.attach_to_buffer(%s)", ft)
+    api.nvim_command(string.format('autocmd NvimTreesitter FileType %s %s', ft, cmd))
   end
+
+  state.run_update()
 end
 
 function M.statusline(indicator_size)
-  local indicator_size = indicator_size or 1000
-  local expr = require"nvim-treesitter.utils".expression_at_point()
-  local current_node =
-    require'nvim-treesitter.node_movement'.current_node[api.nvim_get_current_buf()]
-
-  local indicator = ""
-  while expr and (#indicator + #(expr:type()) + 5) < indicator_size do
-
-    local prefix = ""
-    if expr:parent() then
-      prefix = "->"
-    end
+  local indicator_size = indicator_size or 100
+  local bufnr = api.nvim_get_current_buf()
+  local buf_state = state.get_buf_state(bufnr)
+  if not buf_state then return "" end
 
+  local current_node = buf_state.current_node
+  if not current_node then return "" end
 
-    if expr == current_node then
-      indicator = string.format("%s[%s]%s", prefix, expr:type(), indicator)
-    else
-      indicator = prefix .. expr:type() .. indicator
-    end
+  local expr = current_node:parent()
+  local prefix = ""
+  if expr then
+    prefix = "->"
+  end
 
+  local indicator = current_node:type()
+  while expr and (#indicator + #(expr:type()) + 5) < indicator_size do
+    indicator = expr:type() .. prefix .. indicator
     expr = expr:parent()
   end
 
diff --git a/lua/nvim-treesitter/configs.lua b/lua/nvim-treesitter/configs.lua
index 9695da5af..31f01a72a 100644
--- a/lua/nvim-treesitter/configs.lua
+++ b/lua/nvim-treesitter/configs.lua
@@ -1,6 +1,8 @@
 local api = vim.api
+
 local queries = require'nvim-treesitter.query'
-local parser_utils = require'nvim-treesitter.parsers'
+local utils = require'nvim-treesitter.utils'
+
 local parsers = {}
 
 parsers.javascript = {
@@ -218,28 +220,28 @@ local config = {
       enable = false,
       disable = {},
       keymaps = {
+        init_selection="gnn",
         node_incremental="grn",
-        scope_incremental="grc"
+        scope_incremental="grc",
+        node_decremental="grm"
       },
-      is_supported = function() return true end
+      is_supported = function(ft)
+        return queries.get_query(ft, 'locals')
+      end
     },
     node_movement = {
       enable = false,
       disable = {},
-      is_supported = function() return true end,
+      is_supported = function(ft)
+        return queries.get_query(ft, 'locals')
+      end,
       keymaps = {
-        move_up = "<a-k>",
-        move_down = "<a-j>",
-        move_left = "<a-h>",
-        move_right = "<a-l>",
+        parent_scope = "<a-k>",
+        child_scope = "<a-j>",
+        next_scope = "<a-l>",
+        previous_scope = "<a-h>",
       },
-    },
-    -- folding = {
-    --   enable = false,
-    --   disable = {},
-    --   keymaps = {},
-    --   is_supported = function() return false end
-    -- }
+    }
   },
   ensure_installed = nil
 }
@@ -279,12 +281,12 @@ local function enable_all(mod, ft)
     end
   end
   if ft then
-    if parser_utils.has_parser(ft) then
+    if utils.has_parser(ft) then
       enable_mod_conf_autocmd(mod, ft)
     end
   else
     for _, ft in pairs(M.available_parsers()) do
-      if parser_utils.has_parser(ft) then
+      if utils.has_parser(ft) then
         enable_mod_conf_autocmd(mod, ft)
       end
     end
@@ -364,7 +366,7 @@ M.commands = {
 -- @param mod: module (string)
 -- @param ft: filetype (string)
 function M.is_enabled(mod, ft)
-  if not M.get_parser_configs()[ft] or not parser_utils.has_parser(ft) then
+  if not M.get_parser_configs()[ft] or not utils.has_parser(ft) then
     return false
   end
 
@@ -378,6 +380,7 @@ function M.is_enabled(mod, ft)
   for _, parser in pairs(module_config.disable) do
     if ft == parser then return false end
   end
+
   return true
 end
 
@@ -393,11 +396,15 @@ function M.setup(user_data)
         config.modules[mod].disable = data.disable
       end
       if config.modules[mod].keymaps and type(data.keymaps) == 'table' then
-        config.modules[mod].keymaps = data.keymaps
+        for f, map in pairs(data.keymaps) do
+          if config.modules[mod].keymaps[f] then
+            config.modules[mod].keymaps[f] = map
+          end
+        end
       end
     elseif mod == 'ensure_installed' then
       config.ensure_installed = data
-      require'nvim-treesitter/install'.ensure_installed(data)
+      require'nvim-treesitter.install'.ensure_installed(data)
     end
   end
 end
diff --git a/lua/nvim-treesitter/health.lua b/lua/nvim-treesitter/health.lua
index 7ba1cae65..a1852162e 100644
--- a/lua/nvim-treesitter/health.lua
+++ b/lua/nvim-treesitter/health.lua
@@ -55,8 +55,6 @@ function locals_health(lang)
   end
 end
 
-
--- TODO(vigoux): Maybe we should move each check to be perform in its own module
 function M.checkhealth()
   -- Installation dependency checks
   health_start('Installation')
diff --git a/lua/nvim-treesitter/highlight.lua b/lua/nvim-treesitter/highlight.lua
index 9cf259639..c1981aff8 100644
--- a/lua/nvim-treesitter/highlight.lua
+++ b/lua/nvim-treesitter/highlight.lua
@@ -1,5 +1,6 @@
 local api = vim.api
 local ts = vim.treesitter
+
 local queries = require'nvim-treesitter.query'
 
 local M = {
diff --git a/lua/nvim-treesitter/incremental_selection.lua b/lua/nvim-treesitter/incremental_selection.lua
index 70eefe37c..ea7a9f71e 100644
--- a/lua/nvim-treesitter/incremental_selection.lua
+++ b/lua/nvim-treesitter/incremental_selection.lua
@@ -1,77 +1,102 @@
 local api = vim.api
-local utils = require'nvim-treesitter.utils'
-local parsers = require'nvim-treesitter.parsers'
-local M = {}
 
-local function node_range_to_vim(node)
-  if not node then return end
+local state = require'nvim-treesitter.state'
+local configs = require'nvim-treesitter.configs'
+local ts_utils = require'nvim-treesitter.ts_utils'
+
+local M = {}
 
+local function update_selection(buf, node)
   local start_row, start_col, end_row, end_col = node:range()
 
-  local select_range = [[
-  call cursor(%d, %d)
-  normal v
-  call cursor(%d, %d)
-  ]]
-  local exec_command = string.format(select_range,
-    start_row+1, start_col+1,
-    end_row+1, end_col+1)
+  if end_row == vim.fn.line('$') then
+    end_col = #vim.fn.getline('$')
+  end
 
-  api.nvim_exec(exec_command, false)
+  vim.fn.setpos(".", { buf, start_row+1, start_col+1, 0 })
+  vim.fn.nvim_exec("normal v", false)
+  vim.fn.setpos(".", { buf, end_row+1, end_col+1, 0 })
 end
 
-local function select_incremental(increment_func)
+local function select_incremental(get_parent)
   return function()
-    local buf, sel_start_line, sel_start_col, _ = unpack(vim.fn.getpos("'<"))
-    local buf, sel_end_line, sel_end_col, _ = unpack(vim.fn.getpos("'>"))
-
-    local node = nil
-    if parsers.has_parser() then
-      local root = parsers.get_parser():parse():root()
-      node = root:named_descendant_for_range(sel_start_line-1, sel_start_col-1, sel_end_line-1, sel_end_col)
-      local node_start_row, node_start_col, node_end_row, node_end_col = node:range()
+    local buf = api.nvim_get_current_buf()
+    local buf_state = state.get_buf_state(buf)
 
-      if (sel_start_line-1) == node_start_row and (sel_start_col-1) == node_start_col
-        and (sel_end_line-1) == node_end_row and sel_end_col == node_end_col then
-        node = increment_func(node)
+    local node
+    -- initialize incremental selection with current range
+    if #buf_state.selection.nodes == 0 then
+      local cur_range = buf_state.selection.range
+      if not cur_range then 
+        local _, cursor_row, cursor_col, _ = unpack(vim.fn.getpos("."))
+        cur_range = { cursor_row, cursor_col, cursor_row, cursor_col + 1 }
       end
+
+      local root = buf_state.parser.tree:root()
+      if not root then return end
+
+      node = root:named_descendant_for_range(cur_range[1]-1, cur_range[2]-1, cur_range[3]-1, cur_range[4]-1) 
+    else
+      node = get_parent(buf_state.selection.nodes[#buf_state.selection.nodes]) 
+    end
+
+    if not node then return end
+
+    if node ~= buf_state.selection.nodes[#buf_state.selection.nodes] then
+      state.insert_selection_node(buf, node)
     end
 
-    return node_range_to_vim(node)
+    update_selection(buf, node)
   end
 end
 
 M.node_incremental = select_incremental(function(node)
-  if node then
-    return node:parent() or node
-  end
+  return node:parent() or node
 end)
 
 M.scope_incremental = select_incremental(function(node)
-  if node then
-    return utils.smallest_containing_scope(node:parent() or node)
-  end
+  return ts_utils.containing_scope(node:parent() or node)
 end)
 
+function M.node_decremental()
+  local buf = api.nvim_get_current_buf()
+  local buf_state = state.get_buf_state(buf)
+
+  local nodes = buf_state.selection.nodes
+  if #nodes < 2 then return end
+
+  state.pop_selection_node(buf)
+
+  local node = nodes[#nodes]
+  update_selection(buf, node)
+end
+
 function M.attach(bufnr)
   local buf = bufnr or api.nvim_get_current_buf()
 
-  local config = require'nvim-treesitter.configs'.get_module('incremental_selection')
+  local config = configs.get_module('incremental_selection')
   for funcname, mapping in pairs(config.keymaps) do
-    api.nvim_buf_set_keymap(buf, 'v', mapping,
-      string.format(":lua require'nvim-treesitter.incremental_selection'.%s()<CR>", funcname), { silent = true })
-    api.nvim_buf_set_keymap(buf, 'o', mapping,
-      string.format(":normal v%s<CR>", mapping), { silent = true })
+
+    if funcname == "init_selection" then
+      local cmd = ":lua require'nvim-treesitter.incremental_selection'.node_incremental()<CR>"
+      api.nvim_buf_set_keymap(buf, 'n', mapping, cmd, { silent = true })
+    else
+      local cmd = string.format(":lua require'nvim-treesitter.incremental_selection'.%s()<CR>", funcname)
+      api.nvim_buf_set_keymap(buf, 'v', mapping, cmd, { silent = true })
+    end
   end
 end
 
 function M.detach(bufnr)
   local buf = bufnr or api.nvim_get_current_buf()
 
-  local config = require'nvim-treesitter.configs'.get_module('incremental_selection')
-  for _, mapping in pairs(config.keymaps) do
-    api.nvim_buf_del_keymap(buf, 'v', mapping)
-    api.nvim_buf_del_keymap(buf, 'o', mapping)
+  local config = configs.get_module('incremental_selection')
+  for f, mapping in pairs(config.keymaps) do
+    if f == "init_selection" then
+      api.nvim_buf_del_keymap(buf, 'n', mapping)
+    else
+      api.nvim_buf_del_keymap(buf, 'v', mapping)
+    end
   end
 end
 
diff --git a/lua/nvim-treesitter/install.lua b/lua/nvim-treesitter/install.lua
index 77e0fccc4..45aec99ca 100644
--- a/lua/nvim-treesitter/install.lua
+++ b/lua/nvim-treesitter/install.lua
@@ -1,38 +1,11 @@
 local api = vim.api
 local fn = vim.fn
 local luv = vim.loop
-local configs = require'nvim-treesitter/configs'
-local parsers = configs.get_parser_configs()
-local has_parser = require'nvim-treesitter/parsers'.has_parser
 
-local M = {}
-
-local function get_package_path()
-  for _, path in pairs(api.nvim_list_runtime_paths()) do
-    if string.match(path, '.*/nvim%-treesitter') then
-      return path
-    end
-  end
-
-  return nil, 'Plugin runtime path not found.'
-end
-
-local function get_cache_dir()
-  local home = fn.get(fn.environ(), 'HOME')
-  local xdg_cache = fn.get(fn.environ(), 'XDG_CACHE_HOME')
+local configs = require'nvim-treesitter.configs'
+local utils = require'nvim-treesitter.utils'
 
-  if xdg_cache == 0 then
-    xdg_cache = home .. '/.cache'
-  end
-
-  if luv.fs_access(xdg_cache, 'RW') then
-    return xdg_cache
-  elseif luv.fs_access('/tmp', 'RW') then
-    return '/tmp'
-  end
-
-  return nil, 'Invalid cache rights, $XDG_CACHE_HOME or /tmp should be read/write'
-end
+local M = {}
 
 local function iter_cmd(cmd_list, i, ft)
   if i == #cmd_list + 1 then return print('Treesitter parser for '..ft..' has been installed') end
@@ -122,7 +95,7 @@ local function install(ft)
     if not string.match(yesno, '^y.*') then return end
   end
 
-  local parser_config = parsers[ft]
+  local parser_config = configs.get_parser_configs()[ft]
   if not parser_config then
     return api.nvim_err_writeln('Parser not available for language '..ft)
   end
@@ -137,10 +110,10 @@ local function install(ft)
     return api.nvim_err_writeln('Git is required on your system to run this command')
   end
 
-  local package_path, err = get_package_path()
+  local package_path, err = utils.get_package_path()
   if err then return api.nvim_err_writeln(err) end
 
-  local cache_folder, err = get_cache_dir()
+  local cache_folder, err = utils.get_cache_dir()
   if err then return api.nvim_err_writeln(err) end
 
   run_install(cache_folder, package_path, ft, install_info)
@@ -157,7 +130,7 @@ M.ensure_installed = function(languages)
   end
 
   for _, ft in ipairs(languages) do
-    if not has_parser(ft) then
+    if not utils.has_parser(ft) then
       install(ft)
     end
   end
diff --git a/lua/nvim-treesitter/locals.lua b/lua/nvim-treesitter/locals.lua
index b16408ac5..313d7655d 100644
--- a/lua/nvim-treesitter/locals.lua
+++ b/lua/nvim-treesitter/locals.lua
@@ -3,11 +3,12 @@
 -- its the way nvim-treesitter uses to "understand" the code
 local api = vim.api
 local ts = vim.treesitter
+
 local queries = require'nvim-treesitter.query'
-local parsers = require'nvim-treesitter.parsers'
+local utils = require'nvim-treesitter.utils'
 
 local M = {
-  locals={}
+  locals = {}
 }
 
 function M.collect_locals(bufnr)
@@ -17,7 +18,7 @@ function M.collect_locals(bufnr)
   local query = queries.get_query(ft, 'locals')
   if not query then return end
 
-  local parser = parsers.get_parser(bufnr, ft)
+  local parser = utils.get_parser(bufnr, ft)
   if not parser then return end
 
   local root = parser:parse():root()
diff --git a/lua/nvim-treesitter/node_movement.lua b/lua/nvim-treesitter/node_movement.lua
index 5d4813bc4..f6f15fced 100644
--- a/lua/nvim-treesitter/node_movement.lua
+++ b/lua/nvim-treesitter/node_movement.lua
@@ -1,88 +1,69 @@
 local api = vim.api
-local parsers = require'nvim-treesitter.parsers'
-local utils = require'nvim-treesitter.utils'
-local M = {}
-
 
-M.NodeMovementKind = {
-  up = 'up',
-  down = 'down',
-  left = 'left',
-  right = 'right',
-}
+local configs = require'nvim-treesitter.configs'
+local state = require'nvim-treesitter.state'
+local ts_utils = require'nvim-treesitter.ts_utils'
 
-M.current_node = {}
+local M = {}
 
-local function node_start_to_vim(node)
-  if not node then return end
+local NodeMovementKind = {
+  parent_scope = 'parent',
+  child_scope = 'child',
+  next_scope = 'next',
+  previous_scope = 'previous',
+}
 
-  local row, col = node:start()
-  local exec_command = string.format('call cursor(%d, %d)', row+1, col+1)
-  api.nvim_exec(exec_command, false)
-end
+local get_node_fn = {
+  [NodeMovementKind.parent_scope] = function(node, curpos)
+    return ts_utils.parent_scope(node, curpos)
+  end,
+  [NodeMovementKind.child_scope] = function(node, curpos)
+    return ts_utils.nested_scope(node, curpos)
+  end,
+  [NodeMovementKind.next_scope] = function(node)
+    return ts_utils.next_scope(node)
+  end,
+  [NodeMovementKind.previous_scope] = function(node)
+    return ts_utils.previous_scope(node)
+  end,
+}
 
 M.do_node_movement = function(kind)
-  local buf, line, col = unpack(vim.fn.getpos("."))
+  local buf = api.nvim_get_current_buf()
 
-  local current_node = M.current_node[buf]
+  local buf_state = state.get_buf_state(buf)
+  if not buf_state then return end
 
-  if current_node then
-    local node_line, node_col = current_node:start()
-    if line-1 ~= node_line or  col-1 ~= node_col then
-      current_node = nil
-    end
-  end
-  local destination_node
+  local current_node = buf_state.current_node
+  if not current_node then return end
 
-  if parsers.has_parser() then
-    local root = parsers.get_parser():parse():root()
-    if not current_node then
-      current_node = root:named_descendant_for_range(line-1, col-1, line-1, col)
-    end
-
-    if kind == M.NodeMovementKind.up then
-       destination_node = current_node:parent()
-    elseif kind == M.NodeMovementKind.down then
-      if current_node:named_child_count() > 0 then
-        destination_node = current_node:named_child(0)
-      else
-        local next_node = utils.get_next_node(current_node)
-        if next_node and next_node:named_child_count() > 0 then
-          destination_node = next_node:named_child(0)
-        end
-      end
-    elseif kind == M.NodeMovementKind.left then
-      destination_node = utils.get_previous_node(current_node, true, true)
-    elseif kind == M.NodeMovementKind.right then
-      destination_node = utils.get_next_node(current_node, true, true)
-    end
-    M.current_node[buf] = destination_node or current_node
-  end
+  local destination_node = get_node_fn[kind](current_node, buf_state.cursor_pos)
 
   if destination_node then
-    node_start_to_vim(destination_node)
+    local row, col = destination_node:start()
+    vim.fn.setpos(".", { buf, row+1, col+1, 0 })
   end
 end
 
-M.move_up = function() M.do_node_movement(M.NodeMovementKind.up) end
-M.move_down = function() M.do_node_movement(M.NodeMovementKind.down) end
-M.move_left = function() M.do_node_movement(M.NodeMovementKind.left) end
-M.move_right = function() M.do_node_movement(M.NodeMovementKind.right) end
+function M.parent_scope() M.do_node_movement(NodeMovementKind.parent_scope) end
+function M.child_scope() M.do_node_movement(NodeMovementKind.child_scope) end
+function M.next_scope() M.do_node_movement(NodeMovementKind.next_scope) end
+function M.previous_scope() M.do_node_movement(NodeMovementKind.previous_scope) end
 
 function M.attach(bufnr)
-  local buf = bufnr or api.nvim_get_current_buf()
+  local bufnr = bufnr or api.nvim_get_current_buf()
 
-  local config = require'nvim-treesitter.configs'.get_module('node_movement')
+  local config = configs.get_module('node_movement')
   for funcname, mapping in pairs(config.keymaps) do
-    api.nvim_buf_set_keymap(buf, 'n', mapping,
-      string.format(":lua require'nvim-treesitter.node_movement'.%s()<CR>", funcname), { silent = true })
+    local cmd = string.format(":lua require'nvim-treesitter.node_movement'.%s()<CR>", funcname)
+    api.nvim_buf_set_keymap(bufnr, 'n', mapping, cmd, { silent = true })
   end
 end
 
 function M.detach(bufnr)
   local buf = bufnr or api.nvim_get_current_buf()
 
-  local config = require'nvim-treesitter.configs'.get_module('node_movement')
+  local config = configs.get_module('node_movement')
   for _, mapping in pairs(config.keymaps) do
     api.nvim_buf_del_keymap(buf, 'n', mapping)
   end
diff --git a/lua/nvim-treesitter/query.lua b/lua/nvim-treesitter/query.lua
index 277c29697..644c33933 100644
--- a/lua/nvim-treesitter/query.lua
+++ b/lua/nvim-treesitter/query.lua
@@ -1,5 +1,3 @@
--- Treesitter utils
-
 local api = vim.api
 local ts = vim.treesitter
 
diff --git a/lua/nvim-treesitter/state.lua b/lua/nvim-treesitter/state.lua
new file mode 100644
index 000000000..9da07ae10
--- /dev/null
+++ b/lua/nvim-treesitter/state.lua
@@ -0,0 +1,114 @@
+local api = vim.api
+
+local utils = require'nvim-treesitter.utils'
+
+local M = {}
+
+local buffers = {}
+
+local g_mode = api.nvim_get_mode().mode
+
+local function get_selection_range()
+  local _, vstart_row, vstart_col, _ = unpack(vim.fn.getpos("v"))
+  local _, cursor_row, cursor_col, _ = unpack(vim.fn.getpos("."))
+  if vstart_row < cursor_row then
+    return vstart_row, vstart_col, cursor_row, cursor_col
+  else
+    return cursor_row, cursor_col, vstart_row, vstart_col
+  end
+end
+
+function M.update()
+  local bufnr = api.nvim_get_current_buf()
+  local buf_config = buffers[bufnr]
+  if not buf_config then return end
+
+  local mode = api.nvim_get_mode().mode
+  local cursor = api.nvim_win_get_cursor(0)
+  local row = cursor[1]
+  local col = cursor[2]
+  if row == buf_config.cursor_pos.row
+    and col == buf_config.cursor_pos.col 
+    and mode == g_mode 
+    then
+    return
+  end
+
+  local root = buf_config.parser.tree:root()
+  if not root then return end
+
+  local new_node = root:named_descendant_for_range(row - 1, col, row - 1, col)
+
+  if new_node ~= buf_config.current_node then
+    buf_config.current_node = new_node
+  end
+
+  -- We only want to update the range when the incremental selection has not started yet
+  if mode == "v" and #buf_config.selection.nodes == 0 then
+    local row_start, col_start, row_end, col_end = get_selection_range()
+    buf_config.selection.range = { row_start, col_start, row_end, col_end }
+  elseif mode ~= "v" then
+    buf_config.selection.nodes = {}
+    buf_config.selection.range = nil
+  end
+
+  g_mode = mode
+  buf_config.cursor_pos.row = row
+  buf_config.cursor_pos.col = col
+end
+
+function M.insert_selection_node(bufnr, range)
+  local buf_config = buffers[bufnr]
+  if not buf_config then return end
+
+  table.insert(buffers[bufnr].selection.nodes, range)
+end
+
+function M.pop_selection_node(bufnr)
+  local buf_config = buffers[bufnr]
+  if not buf_config then return end
+
+  table.remove(
+    buffers[bufnr].selection.nodes,
+    #buffers[bufnr].selection.nodes
+    )
+end
+
+function M.run_update()
+  local cmd = "lua require'nvim-treesitter.state'.update()"
+  api.nvim_command('autocmd NvimTreesitter CursorMoved * '..cmd)
+end
+
+function M.attach_to_buffer(ft)
+  local bufnr = api.nvim_get_current_buf()
+  local ft = ft or api.nvim_buf_get_option(bufnr, 'ft')
+
+  if buffers[bufnr] then return end
+
+  local parser = utils.get_parser(bufnr, ft)
+  if not parser then return end
+
+  buffers[bufnr] = {
+    cursor_pos = {},
+    current_node = nil,
+    selection = {
+      range = nil,
+      nodes = {}
+    },
+    parser = parser,
+  }
+
+  M.update()
+  api.nvim_buf_attach(bufnr, false, {
+      -- TODO(kyazdani): on lines should only parse the changed content
+      -- TODO(kyazdani): add a timer to avoid too frequent updates
+      on_lines = function(_, buf) buffers[buf].parser:parse() end,
+      on_detach = function(bufnr) buffers[bufnr] = nil end,
+    })
+end
+
+function M.get_buf_state(bufnr)
+  return buffers[bufnr]
+end
+
+return M
diff --git a/lua/nvim-treesitter/ts_utils.lua b/lua/nvim-treesitter/ts_utils.lua
new file mode 100644
index 000000000..1445418e0
--- /dev/null
+++ b/lua/nvim-treesitter/ts_utils.lua
@@ -0,0 +1,208 @@
+local api = vim.api
+
+local locals = require'nvim-treesitter.locals'
+
+local M = {}
+
+--- Gets the actual text content of a node
+-- @param node the node to get the text from
+-- @param bufnr the buffer containing the node
+-- @return list of lines of text of the node
+function M.get_node_text(node, bufnr)
+  local bufnr = bufnr or api.nvim_get_current_buf()
+  if not node then return {} end
+
+  -- We have to remember that end_col is end-exclusive
+  local start_row, start_col, end_row, end_col = node:range()
+  if start_row ~= end_row then
+    local lines = api.nvim_buf_get_lines(bufnr, start_row, end_row+1, false)
+    lines[1] = string.sub(lines[1], start_col+1)
+    lines[#lines] = string.sub(lines[#lines], 1, end_col)
+    return lines
+  else
+    local line = api.nvim_buf_get_lines(bufnr, start_row, start_row+1, true)[1]
+    return { string.sub(line, start_col+1, end_col) }
+  end
+end
+
+--- Determines wether a node is the parent of another
+-- @param dest the possible parent
+-- @param source the possible child node
+function M.is_parent(dest, source)
+  if not (dest and source) then return false end
+
+  local current = source
+  while current ~= nil do
+    if current == dest then
+      return true
+    end
+
+    current = current:parent()
+  end
+
+  return false
+end
+
+--- Get next node with same parent
+-- @param node                 node
+-- @param allow_switch_parents allow switching parents if last node
+-- @param allow_next_parent    allow next parent if last node and next parent without children
+function M.get_next_node(node, allow_switch_parents, allow_next_parent)
+  local destination_node
+  local parent = node:parent()
+
+  if not parent then return end
+  local found_pos = 0
+  for i = 0,parent:named_child_count()-1,1 do
+    if parent:named_child(i) == node then
+      found_pos = i
+      break
+    end
+  end
+  if parent:named_child_count() > found_pos + 1 then
+    destination_node = parent:named_child(found_pos + 1)
+  elseif allow_switch_parents then
+    local next_node = M.get_next_node(node:parent())
+    if next_node and next_node:named_child_count() > 0 then
+      destination_node = next_node:named_child(0)
+    elseif next_node and allow_next_parent then
+      destination_node = next_node
+    end
+  end
+
+  return destination_node
+end
+
+--- Get previous node with same parent
+-- @param node                     node
+-- @param allow_switch_parents     allow switching parents if first node
+-- @param allow_previous_parent    allow previous parent if first node and previous parent without children
+function M.get_previous_node(node, allow_switch_parents, allow_previous_parent)
+  local destination_node
+  local parent = node:parent()
+  if not parent then return end
+
+  local found_pos = 0
+  for i = 0,parent:named_child_count()-1,1 do
+    if parent:named_child(i) == node then
+      found_pos = i
+      break
+    end
+  end
+  if 0 < found_pos then
+    destination_node = parent:named_child(found_pos - 1)
+  elseif allow_switch_parents then
+    local previous_node = M.get_previous_node(node:parent())
+    if previous_node and previous_node:named_child_count() > 0 then
+      destination_node = previous_node:named_child(previous_node:named_child_count() - 1)
+    elseif previous_node and allow_previous_parent then
+      destination_node = previous_node
+    end
+  end
+  return destination_node
+end
+
+function M.parent_scope(node, cursor_pos)
+  local bufnr = api.nvim_get_current_buf()
+
+  local scopes = locals.get_scopes(bufnr)
+  if not node or not scopes then return end
+
+  local row = cursor_pos.row
+  local col = cursor_pos.col
+  local iter_node = node
+
+  while iter_node ~= nil do
+    local row_, col_ = iter_node:start()
+    if vim.tbl_contains(scopes, iter_node) and (row_+1 ~= row or col_ ~= col) then
+      return iter_node
+    end
+    iter_node = iter_node:parent()
+  end
+end
+
+function M.containing_scope(node)
+  local bufnr = api.nvim_get_current_buf()
+
+  local scopes = locals.get_scopes(bufnr)
+  if not node or not scopes then return end
+
+  local iter_node = node
+
+  while iter_node ~= nil and not vim.tbl_contains(scopes, iter_node) do
+    iter_node = iter_node:parent()
+  end
+
+  return iter_node or node
+end
+
+function M.get_named_children(node)
+  local nodes = {}
+  for i=0,node:named_child_count() - 1,1 do
+    nodes[i+1] = node:named_child(i)
+  end
+  return nodes
+end
+
+function M.nested_scope(node, cursor_pos)
+  local bufnr = api.nvim_get_current_buf()
+
+  local scopes = locals.get_scopes(bufnr)
+  if not node or not scopes then return end
+
+  local row = cursor_pos.row
+  local col = cursor_pos.col
+  local scope = M.containing_scope(node)
+
+  for _, child in ipairs(M.get_named_children(scope)) do
+    local row_, col_ = child:start()
+    if vim.tbl_contains(scopes, child) and ((row_+1 == row and col_ > col) or row_+1 > row) then
+      return child
+    end
+  end
+end
+
+function M.next_scope(node)
+  local bufnr = api.nvim_get_current_buf()
+
+  local scopes = locals.get_scopes(bufnr)
+  if not node or not scopes then return end
+
+  local scope = M.containing_scope(node)
+
+  local parent = scope:parent()
+  if not parent then return end
+
+  local is_prev = true
+  for _, child in ipairs(M.get_named_children(parent)) do
+    if child == scope then
+      is_prev = false
+    elseif not is_prev and vim.tbl_contains(scopes, child) then
+      return child
+    end
+  end
+end
+
+function M.previous_scope(node)
+  local bufnr = api.nvim_get_current_buf()
+
+  local scopes = locals.get_scopes(bufnr)
+  if not node or not scopes then return end
+
+  local scope = M.containing_scope(node)
+
+  local parent = scope:parent()
+  if not parent then return end
+
+  local is_prev = true
+  local children = M.get_named_children(parent)
+  for i=#children,1,-1 do
+    if children[i] == scope then
+      is_prev = false
+    elseif not is_prev and vim.tbl_contains(scopes, children[i]) then
+      return children[i]
+    end
+  end
+end
+
+return M
diff --git a/lua/nvim-treesitter/utils.lua b/lua/nvim-treesitter/utils.lua
index 9d591eab6..9dc5d17bd 100644
--- a/lua/nvim-treesitter/utils.lua
+++ b/lua/nvim-treesitter/utils.lua
@@ -1,69 +1,10 @@
--- Utils collection for nvim-treesitter
 local api = vim.api
-local parsers = require'nvim-treesitter.parsers'
-local locals = require'nvim-treesitter.locals'
+local fn = vim.fn
+local luv = vim.loop
+local ts = vim.treesitter
 
 local M = {}
 
---- Gets the smallest expression containing the current cursor position
-function M.expression_at_point(bufnr, lang)
-  local bufnr = bufnr or api.nvim_get_current_buf()
-  local lang = lang or api.nvim_buf_get_option(bufnr, 'ft')
-
-  local parser = parsers.get_parser(bufnr, lang)
-  if not parser then return end
-
-  local tsroot = parser:parse():root()
-  if not tsroot then return end
-
-  local curwin = api.nvim_get_current_win()
-
-  if api.nvim_win_get_buf(curwin) == bufnr then
-    local cursor = vim.api.nvim_win_get_cursor(curwin)
-    local current_node = tsroot:named_descendant_for_range(cursor[1] - 1, cursor[2], cursor[1] - 1, cursor[2])
-    return current_node
-  end
-end
-
---- Gets the actual text content of a node
--- @param node the node to get the text from
--- @param bufnr the buffer containing the node
--- @return list of lines of text of the node
-function M.get_node_text(node, bufnr)
-  local bufnr = bufnr or api.nvim_get_current_buf()
-  if not node then return {} end
-
-  -- We have to remember that end_col is end-exclusive
-  local start_row, start_col, end_row, end_col = node:range()
-  if start_row ~= end_row then
-    local lines = api.nvim_buf_get_lines(bufnr, start_row, end_row+1, false)
-    lines[1] = string.sub(lines[1], start_col+1)
-    lines[#lines] = string.sub(lines[#lines], 1, end_col)
-    return lines
-  else
-    local line = api.nvim_buf_get_lines(bufnr, start_row, start_row+1, true)[1]
-    return { string.sub(line, start_col+1, end_col) }
-  end
-end
-
---- Determines wether a node is the parent of another
--- @param dest the possible parent
--- @param source the possible child node
-function M.is_parent(dest, source)
-  if not (dest and source) then return false end
-
-  local current = source
-  while current ~= nil do
-    if current == dest then
-      return true
-    end
-
-    current = current:parent()
-  end
-
-  return false
-end
-
 function M.setup_commands(mod, commands)
   for command_name, def in pairs(commands) do
     local call_fn = string.format("lua require'nvim-treesitter.%s'.commands.%s.run(<f-args>)", mod, command_name)
@@ -77,79 +18,50 @@ function M.setup_commands(mod, commands)
   end
 end
 
---- Gets the smallest scope which contains @param node
-function M.smallest_containing_scope(node, bufnr)
-  local bufnr = bufnr or api.nvim_get_current_buf()
-
-  local root = parsers.get_parser(bufnr):parse():root()
-  if not node then return root end
-
-  local scopes = locals.get_scopes(bufnr)
-  local current = node
-  while current ~= nil and not vim.tbl_contains(scopes, current) do
-    current = current:parent()
+function M.get_package_path()
+  for _, path in pairs(api.nvim_list_runtime_paths()) do
+    if string.match(path, '.*/nvim%-treesitter') then
+      return path
+    end
   end
 
-  return current or root
+  return nil, 'Plugin runtime path not found.'
 end
 
---- Get next node with same parent
--- @param node                 node
--- @param allow_switch_parents allow switching parents if last node
--- @param allow_next_parent    allow next parent if last node and next parent without children
-function M.get_next_node(node, allow_switch_parents, allow_next_parent)
- local destination_node
-  local parent = node:parent()
+function M.get_cache_dir()
+  local home = fn.get(fn.environ(), 'HOME')
+  local xdg_cache = fn.get(fn.environ(), 'XDG_CACHE_HOME')
 
-  if parent then
-    local found_pos = 0
-    for i = 0,parent:named_child_count()-1,1 do
-      if parent:named_child(i) == node then
-        found_pos = i
-        break
-      end
-    end
-    if parent:named_child_count() > found_pos + 1 then
-      destination_node = parent:named_child(found_pos + 1)
-    elseif allow_switch_parents then
-      local next_node = M.get_next_node(node:parent())
-      if next_node and next_node:named_child_count() > 0 then
-        destination_node = next_node:named_child(0)
-      elseif next_node and allow_next_parent then
-        destination_node = next_node
-      end
-    end
+  if xdg_cache == 0 then
+    xdg_cache = home .. '/.cache'
+  end
+
+  if luv.fs_access(xdg_cache, 'RW') then
+    return xdg_cache
+  elseif luv.fs_access('/tmp', 'RW') then
+    return '/tmp'
   end
-  return destination_node
+
+  return nil, 'Invalid cache rights, $XDG_CACHE_HOME or /tmp should be read/write'
 end
 
---- Get previous node with same parent
--- @param node                     node
--- @param allow_switch_parents     allow switching parents if first node
--- @param allow_previous_parent    allow previous parent if first node and previous parent without children
-function M.get_previous_node(node, allow_switch_parents, allow_previous_parent)
-  local destination_node
-  local parent = node:parent()
-  if parent then
-    local found_pos = 0
-    for i = 0,parent:named_child_count()-1,1 do
-      if parent:named_child(i) == node then
-        found_pos = i
-        break
-      end
+function M.has_parser(lang)
+  local lang = lang or api.nvim_buf_get_option(0, 'filetype')
+  return #api.nvim_get_runtime_file('parser/' .. lang .. '.so', false) > 0
+end
+
+function M.get_parser(bufnr, lang)
+  if M.has_parser() then
+    local buf = bufnr or api.nvim_get_current_buf()
+    local lang = lang or api.nvim_buf_get_option(buf, 'ft')
+    if not M[buf] then
+      M[buf] = {}
+    end
+    if not M[buf][lang] then
+      M[buf][lang] = ts.get_parser(buf, lang)
     end
-    if 0 < found_pos then
-      destination_node = parent:named_child(found_pos - 1)
-    elseif allow_switch_parents then
-        local previous_node = M.get_previous_node(node:parent())
-        if previous_node and previous_node:named_child_count() > 0 then
-          destination_node = previous_node:named_child(previous_node:named_child_count() - 1)
-        elseif previous_node and allow_previous_parent then
-          destination_node = previous_node
-        end
-      end
+    return M[buf][lang]
   end
-  return destination_node
 end
 
 return M