feat(treesitter): provide select() #39069

Problem: No public method for treesitter incremental selection.

Solution: Add `vim.treesitter.select()`.

runtime/lua/vim/treesitter.lua

@@ -12,6 +12,7 @@ local M = vim._defer_require('vim.treesitter', {
   language = ..., --- @module 'vim.treesitter.language'
   languagetree = ..., --- @module 'vim.treesitter.languagetree'
   query = ..., --- @module 'vim.treesitter.query'
+  _select = ..., --- @module 'vim.treesitter._select'
 })
 
 local LanguageTree = M.languagetree
@@ -508,4 +509,42 @@ function M.foldexpr(lnum)
   return M._fold.foldexpr(lnum)
 end
 
+--- @class vim.treesitter.select.Opts
+--- @inlinedoc
+---
+--- Number of selections to make in the given direction (default 1)
+--- @field count integer?
+
+--- Starts or adjusts a |Visual| selection at cursor, based on tree nodes.
+---@param direction 'parent'|'child'|'next'|'prev'|'extend_next'|'extend_prev' Direction to select
+---                                                                            towards
+---@param opts vim.treesitter.select.Opts?
+function M.select(direction, opts)
+  vim.validate('direction', direction, 'string')
+  vim.validate('opts', opts, 'table', true)
+  opts = opts or {}
+  if opts.count then
+    vim.validate('count', opts.count, 'number')
+  end
+  local count = opts.count or 1
+
+  if direction == 'parent' then
+    return M._select.select_parent(count)
+  elseif direction == 'child' then
+    return M._select.select_child(count)
+  elseif direction == 'next' then
+    return M._select.select_next(count)
+  elseif direction == 'prev' then
+    return M._select.select_prev(count)
+  elseif direction == 'extend_next' then
+    return M._select.select_grow_next(count)
+  elseif direction == 'extend_prev' then
+    return M._select.select_grow_prev(count)
+  else
+    vim.validate('direction', direction, function()
+      return false, 'Invalid direction'
+    end)
+  end
+end
+
 return M