1 files changed, 142 insertions, 0 deletions
diff --git a/lua/nvim-treesitter/textobjects/shared.lua b/lua/nvim-treesitter/textobjects/shared.lua
new file mode 100644
index 00000000..3a00da42
--- /dev/null
+++ b/lua/nvim-treesitter/textobjects/shared.lua
@@ -0,0 +1,142 @@
+local api = vim.api
+local ts = vim.treesitter
+
+local parsers = require "nvim-treesitter.parsers"
+local queries = require'nvim-treesitter.query'
+local ts_utils = require'nvim-treesitter.ts_utils'
+
+local M = {}
+
+function M.textobject_at_point(query_string)
+  local bufnr = vim.api.nvim_get_current_buf()
+  local lang = parsers.get_buf_lang(bufnr)
+  if not lang then return end
+
+  local row, col = unpack(vim.api.nvim_win_get_cursor(0))
+  row = row - 1
+
+  local matches = {}
+
+  if string.match(query_string, '^@.*') then
+    matches = queries.get_capture_matches(bufnr, query_string, 'textobjects')
+  else
+    local parser = parsers.get_parser(bufnr, lang)
+    local root = parser:parse():root()
+
+    local start_row, _, end_row, _ = root:range()
+
+    local query = ts.parse_query(lang, query_string)
+    for m in queries.iter_prepared_matches(query, root, bufnr, start_row, end_row) do
+      for _, n in pairs(m) do
+        if n.node then
+          table.insert(matches, n)
+        end
+      end
+    end
+  end
+
+  local match_length
+  local smallest_range
+  local earliest_start
+
+  for _, m in pairs(matches) do
+    if m.node and ts_utils.is_in_node_range(m.node, row, col) then
+      local length = ts_utils.node_length(m.node)
+      if not match_length or length < match_length then
+        smallest_range = m
+        match_length = length
+      end
+      -- for nodes with same length take the one with earliest start
+      if match_length and length == smallest_range then
+        local start = m.start
+        if start then
+          local _, _, start_byte = m.start.node:start()
+          if not earliest_start or start_byte < earliest_start then
+            smallest_range = m
+            match_length = length
+            earliest_start = start_byte
+          end
+        end
+      end
+    end
+  end
+
+  if smallest_range then
+    if smallest_range.start then
+      local start_range = {smallest_range.start.node:range()}
+      local node_range = {smallest_range.node:range()}
+      return bufnr, {start_range[1], start_range[2], node_range[3], node_range[4]}, smallest_range.node
+    else
+      return bufnr, {smallest_range.node:range()}, smallest_range.node
+    end
+  end
+end
+
+function M.get_adjacent(forward, node, query_string, same_parent, overlapping_range_ok, bufnr)
+  local fn = forward and M.next_textobject or M.previous_textobject
+  return fn(node,  query_string, same_parent, overlapping_range_ok, bufnr)
+end
+
+function M.next_textobject(node, query_string, same_parent, overlapping_range_ok, bufnr)
+  local node = node or ts_utils.get_node_at_cursor()
+  local bufnr = bufnr or api.nvim_get_current_buf()
+  if not node then return end
+
+  local _, _, node_end = node:end_()
+  local search_start, _
+  if overlapping_range_ok then
+    _, _, search_start = node:start()
+  else
+    _, _, search_start = node:end_()
+  end
+  local function scoring_function(match)
+    if match.node == node then return end
+    if not same_parent or node:parent() == match.node:parent() then
+      local _, _, start = match.node:start()
+      local _, _, end_ = match.node:end_()
+      return start > search_start and end_ >= node_end
+    end
+  end
+  local function filter_function(match)
+    local _, _, node_start = match.node:start()
+    return -node_start
+  end
+
+  local next_node = queries.find_best_match(bufnr, query_string, 'textobjects', scoring_function, filter_function)
+
+  return next_node and next_node.node
+end
+
+function M.previous_textobject(node, query_string, same_parent, overlapping_range_ok, bufnr)
+  local node = node or ts_utils.get_node_at_cursor()
+  local bufnr = bufnr or api.nvim_get_current_buf()
+  if not node then return end
+
+  local _, _, node_start = node:start()
+  local search_end, _
+  if overlapping_range_ok then
+    _, _, search_end = node:end_()
+    search_end = search_end + 1
+  else
+    _, _, search_end = node:start()
+  end
+
+  local function scoring_function(match)
+    if not same_parent or node:parent() == match.node:parent() then
+      local _, _, end_ = match.node:end_()
+      local _, _, start = match.node:start()
+      return end_ < search_end and start < node_start
+    end
+  end
+
+  local function filter_function(match)
+    local _, _, node_end = match.node:end_()
+    return node_end
+  end
+
+  local previous_node = queries.find_best_match(bufnr, query_string, 'textobjects', scoring_function, filter_function)
+
+  return previous_node and previous_node.node
+end
+
+return M