textobj: add incremental node selection

1 files changed, 36 insertions, 0 deletions

diff --git a/lua/nvim-treesitter/textobj.lua b/lua/nvim-treesitter/textobj.lua
new file mode 100644
index 00000000..9460e193
--- /dev/null
+++ b/lua/nvim-treesitter/textobj.lua
@@ -0,0 +1,36 @@
+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 node then
+    local start_row, start_col, end_row, end_col = node:range()
+
+    return {{start_row, start_col}, {end_row, end_col}}
+  else
+    return {{}, {}}
+  end
+end
+
+function M.node_incremental()
+  local buf, sel_start_line, sel_start_col, _ = unpack(vim.fn.getpos("'<"))
+  local buf, sel_end_line, sel_end_col, _ = unpack(vim.fn.getpos("'>"))
+
+  if parsers.has_parser() then
+    local root = parsers.get_parser():parse():root()
+    local 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()
+
+    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
+      return node_range_to_vim(node:parent() or node)
+    else
+      return node_range_to_vim(node)
+    end
+  else
+    return node_range_to_vim()
+  end
+end
+
+return M