Merge pull request #37 from theHamsta/node-movement

Add 'nvim-treesitter/node-movement'

5 files changed, 196 insertions, 14 deletions

diff --git a/README.md b/README.md
index 3903ecb0b..67d90abbc 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,7 @@ require'nvim-treesitter.configs'.setup {
         enable = true,                 -- false will disable the whole extension
         disable = { 'c', 'rust' },     -- list of language that will be disabled
     },
-    textobj = {                        -- this enables incremental selection
+    incremental_selection = {             -- this enables incremental selection
         enable = true,
         disable = { 'cpp', 'lua' },
         keymaps = {                       -- mappings for incremental selection (visual mappings)
@@ -100,6 +100,16 @@ require'nvim-treesitter.configs'.setup {
           scope_incremental = "<leader>f" -- "grc" by default
         }
     },
+    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>",
+        }
+    },
     ensure_installed = 'all' -- one of 'all', 'language', or a list of languages
 }
 EOF
@@ -124,6 +134,7 @@ 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
 
 You can find the roadmap [here](https://github.com/nvim-treesitter/nvim-treesitter/projects/1).
 The roadmap and all features of this plugin are open to change, and any suggestion will be highly appreciated!
diff --git a/doc/nvim-treesitter.txt b/doc/nvim-treesitter.txt
index 55ada1596..ceb834be1 100644
--- a/doc/nvim-treesitter.txt
+++ b/doc/nvim-treesitter.txt
@@ -30,19 +30,29 @@ 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
-      },
-      textobj = {                        -- this enables incremental selection
-          enable = true,
-          disable = { 'cpp', 'lua' },
-          keymaps = {                       -- mappings for visual selection
-            node_incremental = "<leader>e",  -- "grn" by default,
-            scope_incremental = "<leader>f" -- "grc" by default
-          }
-      },
-      ensure_installed = 'all'  -- can be one of 'all', 'language' or {'language1', 'language2' ... }
+    highlight = {
+        enable = true,                 -- false will disable the whole extension
+        disable = { 'c', 'rust' },     -- list of language that will be disabled
+    },
+    incremental_selection = {             -- this enables 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
+        }
+    },
+    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>",
+        }
+    },
+    ensure_installed = 'all' -- one of 'all', 'language', or a list of languages
   }
 <
 
diff --git a/lua/nvim-treesitter/configs.lua b/lua/nvim-treesitter/configs.lua
index 10dcc9605..9695da5af 100644
--- a/lua/nvim-treesitter/configs.lua
+++ b/lua/nvim-treesitter/configs.lua
@@ -223,6 +223,17 @@ local config = {
       },
       is_supported = function() return true end
     },
+    node_movement = {
+      enable = false,
+      disable = {},
+      is_supported = function() return true end,
+      keymaps = {
+        move_up = "<a-k>",
+        move_down = "<a-j>",
+        move_left = "<a-h>",
+        move_right = "<a-l>",
+      },
+    },
     -- folding = {
     --   enable = false,
     --   disable = {},
diff --git a/lua/nvim-treesitter/node_movement.lua b/lua/nvim-treesitter/node_movement.lua
new file mode 100644
index 000000000..5d4813bc4
--- /dev/null
+++ b/lua/nvim-treesitter/node_movement.lua
@@ -0,0 +1,91 @@
+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',
+}
+
+M.current_node = {}
+
+local function node_start_to_vim(node)
+  if not node then return end
+
+  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
+
+M.do_node_movement = function(kind)
+  local buf, line, col = unpack(vim.fn.getpos("."))
+
+  local current_node = M.current_node[buf]
+
+  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
+
+  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
+
+  if destination_node then
+    node_start_to_vim(destination_node)
+  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.attach(bufnr)
+  local buf = bufnr or api.nvim_get_current_buf()
+
+  local config = require'nvim-treesitter.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 })
+  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')
+  for _, mapping in pairs(config.keymaps) do
+    api.nvim_buf_del_keymap(buf, 'n', mapping)
+  end
+end
+
+return M
diff --git a/lua/nvim-treesitter/utils.lua b/lua/nvim-treesitter/utils.lua
index 391863f0d..9d591eab6 100644
--- a/lua/nvim-treesitter/utils.lua
+++ b/lua/nvim-treesitter/utils.lua
@@ -93,4 +93,63 @@ function M.smallest_containing_scope(node, bufnr)
   return current or root
 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 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
+  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 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 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
+  end
+  return destination_node
+end
+
 return M