neovim/runtime/lua/vim/treesitter/query.lua

--- @brief This Lua |treesitter-query| interface allows you to create queries and use them to parse
--- text. See |vim.treesitter.query.parse()| for a working example.

local api = vim.api
local language = require('vim.treesitter.language')
local memoize = vim.func._memoize

local MODELINE_FORMAT = '^;+%s*inherits%s*:?%s*([a-z_,()]+)%s*$'
local EXTENDS_FORMAT = '^;+%s*extends%s*$'

local M = {}

local function is_directive(name)
  return string.sub(name, -1) == '!'
end

---@nodoc
---@class vim.treesitter.query.ProcessedPredicate
---@field [1] string predicate name
---@field [2] boolean should match
---@field [3] (integer|string)[] the original predicate

---@alias vim.treesitter.query.ProcessedDirective (integer|string)[]

---@nodoc
---@class vim.treesitter.query.ProcessedPattern {
---@field predicates vim.treesitter.query.ProcessedPredicate[]
---@field directives vim.treesitter.query.ProcessedDirective[]

--- Splits the query patterns into predicates and directives.
---@param patterns table<integer, (integer|string)[][]>
---@return table<integer, vim.treesitter.query.ProcessedPattern>
---@return boolean
local function process_patterns(patterns)
  ---@type table<integer, vim.treesitter.query.ProcessedPattern>
  local processed_patterns = {}
  local has_combined = false

  for k, pattern_list in pairs(patterns) do
    ---@type vim.treesitter.query.ProcessedPredicate[]
    local predicates = {}
    ---@type vim.treesitter.query.ProcessedDirective[]
    local directives = {}

    for _, pattern in ipairs(pattern_list) do
      -- Note: tree-sitter strips the leading # from predicates for us.
      local pred_name = pattern[1]
      ---@cast pred_name string

      if is_directive(pred_name) then
        table.insert(directives, pattern)
        if vim.deep_equal(pattern, { 'set!', 'injection.combined' }) then
          has_combined = true
        end
      else
        local should_match = true
        if pred_name:match('^not%-') then
          pred_name = pred_name:sub(5)
          should_match = false
        end
        table.insert(predicates, { pred_name, should_match, pattern })
      end
    end

    processed_patterns[k] = { predicates = predicates, directives = directives }
  end

  return processed_patterns, has_combined
end

---@nodoc
---Parsed query, see |vim.treesitter.query.parse()|
---
---@class vim.treesitter.Query
---@field lang string parser language name
---@field captures string[] list of (unique) capture names defined in query
---@field info vim.treesitter.QueryInfo query context (e.g. captures, predicates, directives)
---@field query TSQuery userdata query object
---@field has_combined_injections boolean whether the query contains combined injections
---@field private _processed_patterns table<integer, vim.treesitter.query.ProcessedPattern>
local Query = {}
Query.__index = Query

---@package
---@see vim.treesitter.query.parse
---@param lang string
---@param ts_query TSQuery
---@return vim.treesitter.Query
function Query.new(lang, ts_query)
  local self = setmetatable({}, Query)
  local query_info = ts_query:inspect() ---@type TSQueryInfo
  self.query = ts_query
  self.lang = lang
  self.info = {
    captures = query_info.captures,
    patterns = query_info.patterns,
  }
  self.captures = self.info.captures
  self._processed_patterns, self.has_combined_injections = process_patterns(self.info.patterns)
  return self
end

---@nodoc
---Information for Query, see |vim.treesitter.query.parse()|
---@class vim.treesitter.QueryInfo
---
---List of (unique) capture names defined in query.
---@field captures string[]
---
---Contains information about predicates and directives.
---Key is pattern id, and value is list of predicates or directives defined in the pattern.
---A predicate or directive is a list of (integer|string); integer represents `capture_id`, and
---string represents (literal) arguments to predicate/directive. See |treesitter-predicates|
---and |treesitter-directives| for more details.
---@field patterns table<integer, (integer|string)[][]>

---@param files string[]
---@return string[]
local function dedupe_files(files)
  local result = {}
  ---@type table<string,boolean>
  local seen = {}

  for _, path in ipairs(files) do
    if not seen[path] then
      table.insert(result, path)
      seen[path] = true
    end
  end

  return result
end

local function safe_read(filename, read_quantifier)
  local file, err = io.open(filename, 'r')
  if not file then
    error(err)
  end
  local content = file:read(read_quantifier)
  io.close(file)
  return content
end

--- Adds {ilang} to {base_langs}, only if {ilang} is different than {lang}
---
---@return boolean true If lang == ilang
local function add_included_lang(base_langs, lang, ilang)
  if lang == ilang then
    return true
  end
  table.insert(base_langs, ilang)
  return false
end

--- Gets the list of files used to make up a query
---
---@param lang string Language to get query for
---@param query_name string Name of the query to load (e.g., "highlights")
---@param is_included? boolean Internal parameter, most of the time left as `nil`
---@return string[] query_files List of files to load for given query and language
function M.get_files(lang, query_name, is_included)
  local query_path = string.format('queries/%s/%s.scm', lang, query_name)
  local lang_files = dedupe_files(api.nvim_get_runtime_file(query_path, true))

  if #lang_files == 0 then
    return {}
  end

  local base_query = nil ---@type string?
  local extensions = {}

  local base_langs = {} ---@type string[]

  -- Now get the base languages by looking at the first line of every file
  -- The syntax is the following :
  -- ;+ inherits: ({language},)*{language}
  --
  -- {language} ::= {lang} | ({lang})
  for _, filename in ipairs(lang_files) do
    local file, err = io.open(filename, 'r')
    if not file then
      error(err)
    end

    local extension = false

    for modeline in
      ---@return string
      function()
        return file:read('*l')
      end
    do
      if not vim.startswith(modeline, ';') then
        break
      end

      local langlist = modeline:match(MODELINE_FORMAT)
      if langlist then
        ---@diagnostic disable-next-line:param-type-mismatch
        for _, incllang in ipairs(vim.split(langlist, ',', true)) do
          local is_optional = incllang:match('%(.*%)')

          if is_optional then
            if not is_included then
              if add_included_lang(base_langs, lang, incllang:sub(2, #incllang - 1)) then
                extension = true
              end
            end
          else
            if add_included_lang(base_langs, lang, incllang) then
              extension = true
            end
          end
        end
      elseif modeline:match(EXTENDS_FORMAT) then
        extension = true
      end
    end

    if extension then
      table.insert(extensions, filename)
    elseif base_query == nil then
      base_query = filename
    end
    io.close(file)
  end

  local query_files = {}
  for _, base_lang in ipairs(base_langs) do
    local base_files = M.get_files(base_lang, query_name, true)
    vim.list_extend(query_files, base_files)
  end
  vim.list_extend(query_files, { base_query })
  vim.list_extend(query_files, extensions)

  return query_files
end

---@param filenames string[]
---@return string
local function read_query_files(filenames)
  local contents = {}

  for _, filename in ipairs(filenames) do
    table.insert(contents, safe_read(filename, '*a'))
  end

  return table.concat(contents, '')
end

-- The explicitly set query strings from |vim.treesitter.query.set()|
---@type table<string,table<string,string>>
local explicit_queries = setmetatable({}, {
  __index = function(t, k)
    local lang_queries = {}
    rawset(t, k, lang_queries)

    return lang_queries
  end,
})

--- Sets the runtime query named {query_name} for {lang}
---
--- This allows users to override or extend any runtime files and/or configuration
--- set by plugins.
---
--- For example, you could enable spellchecking of `C` identifiers with the
--- following code:
--- ```lua
--- vim.treesitter.query.set(
---   'c',
---   'highlights',
---   [[;inherits c
---   (identifier) @spell]])
--- ]])
--- ```
---
---@param lang string Language to use for the query
---@param query_name string Name of the query (e.g., "highlights")
---@param text string Query text (unparsed).
function M.set(lang, query_name, text)
  --- @diagnostic disable-next-line: undefined-field LuaLS bad at generics
  M.get:clear(lang, query_name)
  explicit_queries[lang][query_name] = text
end

--- Returns the runtime query {query_name} for {lang}.
---
---@param lang string Language to use for the query
---@param query_name string Name of the query (e.g. "highlights")
---
---@return vim.treesitter.Query? : Parsed query. `nil` if no query files are found.
M.get = memoize('concat-2', function(lang, query_name)
  local query_string ---@type string

  if explicit_queries[lang][query_name] then
    local query_files = {}
    local base_langs = {} ---@type string[]

    for line in explicit_queries[lang][query_name]:gmatch('([^\n]*)\n?') do
      if not vim.startswith(line, ';') then
        break
      end

      local lang_list = line:match(MODELINE_FORMAT)
      if lang_list then
        for _, incl_lang in ipairs(vim.split(lang_list, ',')) do
          local is_optional = incl_lang:match('%(.*%)')

          if is_optional then
            add_included_lang(base_langs, lang, incl_lang:sub(2, #incl_lang - 1))
          else
            add_included_lang(base_langs, lang, incl_lang)
          end
        end
      elseif line:match(EXTENDS_FORMAT) then
        table.insert(base_langs, lang)
      end
    end

    for _, base_lang in ipairs(base_langs) do
      local base_files = M.get_files(base_lang, query_name, true)
      vim.list_extend(query_files, base_files)
    end

    query_string = read_query_files(query_files) .. explicit_queries[lang][query_name]
  else
    local query_files = M.get_files(lang, query_name)
    query_string = read_query_files(query_files)
  end

  if #query_string == 0 then
    return nil
  end

  return M.parse(lang, query_string)
end, false)

api.nvim_create_autocmd('OptionSet', {
  pattern = { 'runtimepath' },
  group = api.nvim_create_augroup('nvim.treesitter.query_cache_reset', { clear = true }),
  callback = function()
    --- @diagnostic disable-next-line: undefined-field LuaLS bad at generics
    M.get:clear()
  end,
})

--- Parses a {query} string and returns a `Query` object (|lua-treesitter-query|), which can be used
--- to search the tree for the query patterns (via |Query:iter_captures()|, |Query:iter_matches()|),
--- or inspect the query via these fields:
---   - `captures`: a list of unique capture names defined in the query (alias: `info.captures`).
---   - `info.patterns`: information about predicates.
---
--- Example:
--- ```lua
--- local query = vim.treesitter.query.parse('vimdoc', [[
---   ; query
---   ((h1) @str
---     (#trim! @str 1 1 1 1))
--- ]])
--- local tree = vim.treesitter.get_parser():parse()[1]
--- for id, node, metadata in query:iter_captures(tree:root(), 0) do
---    -- Print the node name and source text.
---    vim.print({node:type(), vim.treesitter.get_node_text(node, vim.api.nvim_get_current_buf())})
--- end
--- ```
---
---@param lang string Language to use for the query
---@param query string Query text, in s-expr syntax
---
---@return vim.treesitter.Query : Parsed query
---
---@see [vim.treesitter.query.get()]
M.parse = memoize('concat-2', function(lang, query)
  assert(language.add(lang))
  local ts_query = vim._ts_parse_query(lang, query)
  return Query.new(lang, ts_query)
end, false)

--- Implementations of predicates that can optionally be prefixed with "any-".
---
--- These functions contain the implementations for each predicate, correctly
--- handling the "any" vs "all" semantics. They are called from the
--- predicate_handlers table with the appropriate arguments for each predicate.
local impl = {
  --- @param match table<integer,TSNode[]>
  --- @param source integer|string
  --- @param predicate any[]
  --- @param any boolean
  ['eq'] = function(match, source, predicate, any)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      local node_text = vim.treesitter.get_node_text(node, source)

      local str ---@type string
      if type(predicate[3]) == 'string' then
        -- (#eq? @aa "foo")
        str = predicate[3]
      else
        -- (#eq? @aa @bb)
        local other = assert(match[predicate[3]])
        assert(#other == 1, '#eq? does not support comparison with captures on multiple nodes')
        str = vim.treesitter.get_node_text(other[1], source)
      end

      local res = str ~= nil and node_text == str
      if any and res then
        return true
      elseif not any and not res then
        return false
      end
    end

    return not any
  end,

  --- @param match table<integer,TSNode[]>
  --- @param source integer|string
  --- @param predicate any[]
  --- @param any boolean
  ['lua-match'] = function(match, source, predicate, any)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      local regex = predicate[3]
      local res = string.find(vim.treesitter.get_node_text(node, source), regex) ~= nil
      if any and res then
        return true
      elseif not any and not res then
        return false
      end
    end

    return not any
  end,

  ['match'] = (function()
    local magic_prefixes = { ['\\v'] = true, ['\\m'] = true, ['\\M'] = true, ['\\V'] = true }
    local function check_magic(str)
      if string.len(str) < 2 or magic_prefixes[string.sub(str, 1, 2)] then
        return str
      end
      return '\\v' .. str
    end

    local compiled_vim_regexes = setmetatable({}, {
      __index = function(t, pattern)
        local res = vim.regex(check_magic(pattern))
        rawset(t, pattern, res)
        return res
      end,
    })

    --- @param match table<integer,TSNode[]>
    --- @param source integer|string
    --- @param predicate any[]
    --- @param any boolean
    return function(match, source, predicate, any)
      local nodes = match[predicate[2]]
      if not nodes or #nodes == 0 then
        return true
      end

      for _, node in ipairs(nodes) do
        local regex = compiled_vim_regexes[predicate[3]] ---@type vim.regex
        local res = regex:match_str(vim.treesitter.get_node_text(node, source))
        if any and res then
          return true
        elseif not any and not res then
          return false
        end
      end
      return not any
    end
  end)(),

  --- @param match table<integer,TSNode[]>
  --- @param source integer|string
  --- @param predicate any[]
  --- @param any boolean
  ['contains'] = function(match, source, predicate, any)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      local node_text = vim.treesitter.get_node_text(node, source)

      for i = 3, #predicate do
        local res = string.find(node_text, predicate[i], 1, true)
        if any and res then
          return true
        elseif not any and not res then
          return false
        end
      end
    end

    return not any
  end,
}

---@alias TSPredicate fun(match: table<integer,TSNode[]>, pattern: integer, source: integer|string, predicate: any[]): boolean

-- Predicate handler receive the following arguments
-- (match, pattern, bufnr, predicate)
---@type table<string,TSPredicate>
local predicate_handlers = {
  ['eq?'] = function(match, _, source, predicate)
    return impl['eq'](match, source, predicate, false)
  end,

  ['any-eq?'] = function(match, _, source, predicate)
    return impl['eq'](match, source, predicate, true)
  end,

  ['lua-match?'] = function(match, _, source, predicate)
    return impl['lua-match'](match, source, predicate, false)
  end,

  ['any-lua-match?'] = function(match, _, source, predicate)
    return impl['lua-match'](match, source, predicate, true)
  end,

  ['match?'] = function(match, _, source, predicate)
    return impl['match'](match, source, predicate, false)
  end,

  ['any-match?'] = function(match, _, source, predicate)
    return impl['match'](match, source, predicate, true)
  end,

  ['contains?'] = function(match, _, source, predicate)
    return impl['contains'](match, source, predicate, false)
  end,

  ['any-contains?'] = function(match, _, source, predicate)
    return impl['contains'](match, source, predicate, true)
  end,

  ['any-of?'] = function(match, _, source, predicate)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      local node_text = vim.treesitter.get_node_text(node, source)

      -- Since 'predicate' will not be used by callers of this function, use it
      -- to store a string set built from the list of words to check against.
      local string_set = predicate['string_set'] --- @type table<string, boolean>
      if not string_set then
        string_set = {}
        for i = 3, #predicate do
          string_set[predicate[i]] = true
        end
        predicate['string_set'] = string_set
      end

      if string_set[node_text] then
        return true
      end
    end

    return false
  end,

  ['has-ancestor?'] = function(match, _, _, predicate)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      if node:__has_ancestor(predicate) then
        return true
      end
    end
    return false
  end,

  ['has-parent?'] = function(match, _, _, predicate)
    local nodes = match[predicate[2]]
    if not nodes or #nodes == 0 then
      return true
    end

    for _, node in ipairs(nodes) do
      if vim.list_contains({ unpack(predicate, 3) }, node:parent():type()) then
        return true
      end
    end
    return false
  end,
}

-- As we provide lua-match? also expose vim-match?
predicate_handlers['vim-match?'] = predicate_handlers['match?']
predicate_handlers['any-vim-match?'] = predicate_handlers['any-match?']

---@nodoc
---@class vim.treesitter.query.TSMetadata
---@field range? Range
---@field conceal? string
---@field [integer]? vim.treesitter.query.TSMetadata
---@field [string]? integer|string

---@alias TSDirective fun(match: table<integer,TSNode[]>, _, _, predicate: (string|integer)[], metadata: vim.treesitter.query.TSMetadata)

-- Predicate handler receive the following arguments
-- (match, pattern, bufnr, predicate)

-- Directives store metadata or perform side effects against a match.
-- Directives should always end with a `!`.
-- Directive handler receive the following arguments
-- (match, pattern, bufnr, predicate, metadata)
---@type table<string,TSDirective>
local directive_handlers = {
  ['set!'] = function(_, _, _, pred, metadata)
    if #pred >= 3 and type(pred[2]) == 'number' then
      -- (#set! @capture key value)
      local capture_id, key, value = pred[2], pred[3], pred[4]
      if not metadata[capture_id] then
        metadata[capture_id] = {}
      end
      metadata[capture_id][key] = value
    else
      -- (#set! key value)
      local key, value = pred[2], pred[3]
      metadata[key] = value or true
    end
  end,
  -- Shifts the range of a node.
  -- Example: (#offset! @_node 0 1 0 -1)
  ['offset!'] = function(match, _, _, pred, metadata)
    local capture_id = pred[2] --[[@as integer]]
    local nodes = match[capture_id]
    if not nodes or #nodes == 0 then
      return
    end
    assert(#nodes == 1, '#offset! does not support captures on multiple nodes')

    local node = nodes[1]

    if not metadata[capture_id] then
      metadata[capture_id] = {}
    end

    local range = metadata[capture_id].range or { node:range() }
    local start_row_offset = pred[3] or 0
    local start_col_offset = pred[4] or 0
    local end_row_offset = pred[5] or 0
    local end_col_offset = pred[6] or 0

    range[1] = range[1] + start_row_offset
    range[2] = range[2] + start_col_offset
    range[3] = range[3] + end_row_offset
    range[4] = range[4] + end_col_offset

    -- If this produces an invalid range, we just skip it.
    if range[1] < range[3] or (range[1] == range[3] and range[2] <= range[4]) then
      metadata[capture_id].range = range
    end
  end,
  -- Transform the content of the node
  -- Example: (#gsub! @_node ".*%.(.*)" "%1")
  ['gsub!'] = function(match, _, bufnr, pred, metadata)
    assert(#pred == 4)

    local id = pred[2]
    assert(type(id) == 'number')

    local nodes = match[id]
    if not nodes or #nodes == 0 then
      return
    end
    assert(#nodes == 1, '#gsub! does not support captures on multiple nodes')
    local node = nodes[1]
    local text = vim.treesitter.get_node_text(node, bufnr, { metadata = metadata[id] }) or ''

    if not metadata[id] then
      metadata[id] = {}
    end

    local pattern, replacement = pred[3], pred[4]
    assert(type(pattern) == 'string')
    assert(type(replacement) == 'string')

    metadata[id].text = text:gsub(pattern, replacement)
  end,
  -- Trim whitespace from both sides of the node
  -- Example: (#trim! @fold 1 1 1 1)
  ['trim!'] = function(match, _, bufnr, pred, metadata)
    local capture_id = pred[2]
    assert(type(capture_id) == 'number')

    local trim_start_lines = pred[3] == '1'
    local trim_start_cols = pred[4] == '1'
    local trim_end_lines = pred[5] == '1' or not pred[3] -- default true for backwards compatibility
    local trim_end_cols = pred[6] == '1'

    local nodes = match[capture_id]
    if not nodes or #nodes == 0 then
      return
    end
    assert(#nodes == 1, '#trim! does not support captures on multiple nodes')
    local node = nodes[1]

    local start_row, start_col, end_row, end_col = node:range()

    local node_text = vim.split(vim.treesitter.get_node_text(node, bufnr), '\n')
    if end_col == 0 then
      -- get_node_text() will ignore the last line if the node ends at column 0
      node_text[#node_text + 1] = ''
    end

    local end_idx = #node_text
    local start_idx = 1

    if trim_end_lines then
      while end_idx > 0 and node_text[end_idx]:find('^%s*$') do
        end_idx = end_idx - 1
        end_row = end_row - 1
        -- set the end position to the last column of the next line, or 0 if we just trimmed the
        -- last line
        end_col = end_idx > 0 and #node_text[end_idx] or 0
      end
    end
    if trim_end_cols then
      if end_idx == 0 then
        end_row = start_row
        end_col = start_col
      else
        local whitespace_start = node_text[end_idx]:find('(%s*)$')
        end_col = (whitespace_start - 1) + (end_idx == 1 and start_col or 0)
      end
    end

    if trim_start_lines then
      while start_idx <= end_idx and node_text[start_idx]:find('^%s*$') do
        start_idx = start_idx + 1
        start_row = start_row + 1
        start_col = 0
      end
    end
    if trim_start_cols and node_text[start_idx] then
      local _, whitespace_end = node_text[start_idx]:find('^(%s*)')
      whitespace_end = whitespace_end or 0
      start_col = (start_idx == 1 and start_col or 0) + whitespace_end
    end

    -- If this produces an invalid range, we just skip it.
    if start_row < end_row or (start_row == end_row and start_col <= end_col) then
      metadata[capture_id] = metadata[capture_id] or {}
      metadata[capture_id].range = { start_row, start_col, end_row, end_col }
    end
  end,
}

--- @class vim.treesitter.query.add_predicate.Opts
--- @inlinedoc
---
--- Override an existing predicate of the same name
--- @field force? boolean
---
--- Use the correct implementation of the match table where capture IDs map to
--- a list of nodes instead of a single node. Defaults to true. This option will
--- be removed in a future release.
--- @field all? boolean

--- Adds a new predicate to be used in queries
---
---@param name string Name of the predicate, without leading #
---@param handler fun(match: table<integer,TSNode[]>, pattern: integer, source: integer|string, predicate: any[], metadata: vim.treesitter.query.TSMetadata): boolean?
---   - see |vim.treesitter.query.add_directive()| for argument meanings
---@param opts? vim.treesitter.query.add_predicate.Opts
function M.add_predicate(name, handler, opts)
  -- Backward compatibility: old signature had "force" as boolean argument
  if type(opts) == 'boolean' then
    opts = { force = opts }
  end

  opts = opts or {}

  if predicate_handlers[name] and not opts.force then
    error(string.format('Overriding existing predicate %s', name))
  end

  if opts.all ~= false then
    predicate_handlers[name] = handler
  else
    --- @param match table<integer, TSNode[]>
    local function wrapper(match, ...)
      local m = {} ---@type table<integer, TSNode>
      for k, v in pairs(match) do
        if type(k) == 'number' then
          m[k] = v[#v]
        end
      end
      return handler(m, ...)
    end
    predicate_handlers[name] = wrapper
  end
end

--- Adds a new directive to be used in queries
---
--- Handlers can set match level data by setting directly on the
--- metadata object `metadata.key = value`. Additionally, handlers
--- can set node level data by using the capture id on the
--- metadata table `metadata[capture_id].key = value`
---
---@param name string Name of the directive, without leading #
---@param handler fun(match: table<integer,TSNode[]>, pattern: integer, source: integer|string, predicate: any[], metadata: vim.treesitter.query.TSMetadata)
---   - match: A table mapping capture IDs to a list of captured nodes
---   - pattern: the index of the matching pattern in the query file
---   - predicate: list of strings containing the full directive being called, e.g.
---     `(node (#set! conceal "-"))` would get the predicate `{ "#set!", "conceal", "-" }`
---@param opts vim.treesitter.query.add_predicate.Opts
function M.add_directive(name, handler, opts)
  -- Backward compatibility: old signature had "force" as boolean argument
  if type(opts) == 'boolean' then
    opts = { force = opts }
  end

  opts = opts or {}

  if directive_handlers[name] and not opts.force then
    error(string.format('Overriding existing directive %s', name))
  end

  if opts.all then
    directive_handlers[name] = handler
  else
    --- @param match table<integer, TSNode[]>
    local function wrapper(match, ...)
      local m = {} ---@type table<integer, TSNode>
      for k, v in pairs(match) do
        m[k] = v[#v]
      end
      handler(m, ...)
    end
    directive_handlers[name] = wrapper
  end
end

--- Lists the currently available directives to use in queries.
---@return string[] : Supported directives.
function M.list_directives()
  return vim.tbl_keys(directive_handlers)
end

--- Lists the currently available predicates to use in queries.
---@return string[] : Supported predicates.
function M.list_predicates()
  return vim.tbl_keys(predicate_handlers)
end

---@private
---@param pattern_i integer
---@param predicates vim.treesitter.query.ProcessedPredicate[]
---@param captures table<integer, TSNode[]>
---@param source integer|string
---@return boolean whether the predicates match
function Query:_match_predicates(predicates, pattern_i, captures, source)
  for _, predicate in ipairs(predicates) do
    local processed_name = predicate[1]
    local should_match = predicate[2]
    local orig_predicate = predicate[3]

    local handler = predicate_handlers[processed_name]
    if not handler then
      error(string.format('No handler for %s', orig_predicate[1]))
      return false
    end

    local does_match = handler(captures, pattern_i, source, orig_predicate)
    if does_match ~= should_match then
      return false
    end
  end
  return true
end

---@private
---@param pattern_i integer
---@param directives vim.treesitter.query.ProcessedDirective[]
---@param source integer|string
---@param captures table<integer, TSNode[]>
---@return vim.treesitter.query.TSMetadata metadata
function Query:_apply_directives(directives, pattern_i, captures, source)
  ---@type vim.treesitter.query.TSMetadata
  local metadata = {}

  for _, directive in pairs(directives) do
    local handler = directive_handlers[directive[1]]

    if not handler then
      error(string.format('No handler for %s', directive[1]))
    end

    handler(captures, pattern_i, source, directive, metadata)
  end

  return metadata
end

--- Returns the start and stop value if set else the node's range.
-- When the node's range is used, the stop is incremented by 1
-- to make the search inclusive.
---@param start integer?
---@param stop integer?
---@param node TSNode
---@return integer, integer
local function value_or_node_range(start, stop, node)
  if start == nil then
    start = node:start()
  end
  if stop == nil then
    stop = node:end_() + 1 -- Make stop inclusive
  end

  return start, stop
end

--- Iterates over all captures from all matches in {node}.
---
--- {source} is required if the query contains predicates; then the caller
--- must ensure to use a freshly parsed tree consistent with the current
--- text of the buffer (if relevant). {start} and {stop} can be used to limit
--- matches inside a row range (this is typically used with root node
--- as the {node}, i.e., to get syntax highlight matches in the current
--- viewport). When omitted, the {start} and {stop} row values are used from the given node.
---
--- The iterator returns four values:
--- 1. the numeric id identifying the capture
--- 2. the captured node
--- 3. metadata from any directives processing the match
--- 4. the match itself
---
--- Example: how to get captures by name:
--- ```lua
--- for id, node, metadata, match in query:iter_captures(tree:root(), bufnr, first, last) do
---   local name = query.captures[id] -- name of the capture in the query
---   -- typically useful info about the node:
---   local type = node:type() -- type of the captured node
---   local row1, col1, row2, col2 = node:range() -- range of the capture
---   -- ... use the info here ...
--- end
--- ```
---
---@param node TSNode under which the search will occur
---@param source (integer|string) Source buffer or string to extract text from
---@param start? integer Starting line for the search. Defaults to `node:start()`.
---@param stop? integer Stopping line for the search (end-exclusive). Defaults to `node:end_()`.
---
---@return (fun(end_line: integer|nil): integer, TSNode, vim.treesitter.query.TSMetadata, TSQueryMatch, TSTree):
---        capture id, capture node, metadata, match, tree
---
---@note Captures are only returned if the query pattern of a specific capture contained predicates.
function Query:iter_captures(node, source, start, stop)
  if type(source) == 'number' and source == 0 then
    source = api.nvim_get_current_buf()
  end

  start, stop = value_or_node_range(start, stop, node)

  -- Copy the tree to ensure it is valid during the entire lifetime of the iterator
  local tree = node:tree():copy()
  local cursor = vim._create_ts_querycursor(node, self.query, start, stop, { match_limit = 256 })

  -- For faster checks that a match is not in the cache.
  local highest_cached_match_id = -1
  ---@type table<integer, vim.treesitter.query.TSMetadata>
  local match_cache = {}

  local function iter(end_line)
    local capture, captured_node, match = cursor:next_capture()

    if not capture then
      return
    end

    local match_id, pattern_i = match:info()

    --- @type vim.treesitter.query.TSMetadata
    local metadata
    if match_id <= highest_cached_match_id then
      metadata = match_cache[match_id]
    end

    if not metadata then
      metadata = {}

      local processed_pattern = self._processed_patterns[pattern_i]
      if processed_pattern then
        local captures = match:captures()

        local predicates = processed_pattern.predicates
        if not self:_match_predicates(predicates, pattern_i, captures, source) then
          cursor:remove_match(match_id)
          if end_line and captured_node:range() > end_line then
            return nil, captured_node, nil, nil
          end
          return iter(end_line) -- tail call: try next match
        end

        local directives = processed_pattern.directives
        metadata = self:_apply_directives(directives, pattern_i, captures, source)
      end

      highest_cached_match_id = math.max(highest_cached_match_id, match_id)
      match_cache[match_id] = metadata
    end

    return capture, captured_node, metadata, match, tree
  end
  return iter
end

--- Iterates the matches of self on a given range.
---
--- Iterate over all matches within a {node}. The arguments are the same as for
--- |Query:iter_captures()| but the iterated values are different: an (1-based)
--- index of the pattern in the query, a table mapping capture indices to a list
--- of nodes, and metadata from any directives processing the match.
---
--- Example:
---
--- ```lua
--- for pattern, match, metadata in cquery:iter_matches(tree:root(), bufnr, 0, -1) do
---   for id, nodes in pairs(match) do
---     local name = query.captures[id]
---     for _, node in ipairs(nodes) do
---       -- `node` was captured by the `name` capture in the match
---
---       local node_data = metadata[id] -- Node level metadata
---       -- ... use the info here ...
---     end
---   end
--- end
--- ```
---
---
---@param node TSNode under which the search will occur
---@param source (integer|string) Source buffer or string to search
---@param start? integer Starting line for the search. Defaults to `node:start()`.
---@param stop? integer Stopping line for the search (end-exclusive). Defaults to `node:end_()`.
---@param opts? table Optional keyword arguments:
---   - max_start_depth (integer) if non-zero, sets the maximum start depth
---     for each match. This is used to prevent traversing too deep into a tree.
---   - match_limit (integer) Set the maximum number of in-progress matches (Default: 256).
--- - all (boolean) When `false` (default `true`), the returned table maps capture IDs to a single
---   (last) node instead of the full list of matching nodes. This option is only for backward
---   compatibility and will be removed in a future release.
---
---@return (fun(): integer, table<integer, TSNode[]>, vim.treesitter.query.TSMetadata, TSTree): pattern id, match, metadata, tree
function Query:iter_matches(node, source, start, stop, opts)
  opts = opts or {}
  opts.match_limit = opts.match_limit or 256

  if type(source) == 'number' and source == 0 then
    source = api.nvim_get_current_buf()
  end

  start, stop = value_or_node_range(start, stop, node)

  -- Copy the tree to ensure it is valid during the entire lifetime of the iterator
  local tree = node:tree():copy()
  local cursor = vim._create_ts_querycursor(node, self.query, start, stop, opts)

  local function iter()
    local match = cursor:next_match()

    if not match then
      return
    end

    local match_id, pattern_i = match:info()
    local processed_pattern = self._processed_patterns[pattern_i]
    local captures = match:captures()

    --- @type vim.treesitter.query.TSMetadata
    local metadata = {}
    if processed_pattern then
      local predicates = processed_pattern.predicates
      if not self:_match_predicates(predicates, pattern_i, captures, source) then
        cursor:remove_match(match_id)
        return iter() -- tail call: try next match
      end
      local directives = processed_pattern.directives
      metadata = self:_apply_directives(directives, pattern_i, captures, source)
    end

    if opts.all == false then
      -- Convert the match table into the old buggy version for backward
      -- compatibility. This is slow, but we only do it when the caller explicitly opted into it by
      -- setting `all` to `false`.
      local old_match = {} ---@type table<integer, TSNode>
      for k, v in pairs(captures or {}) do
        old_match[k] = v[#v]
      end
      return pattern_i, old_match, metadata
    end

    -- TODO(lewis6991): create a new function that returns {match, metadata}
    return pattern_i, captures, metadata, tree
  end
  return iter
end

--- Optional keyword arguments:
--- @class vim.treesitter.query.lint.Opts
--- @inlinedoc
---
--- Language(s) to use for checking the query.
--- If multiple languages are specified, queries are validated for all of them
--- @field langs? string|string[]
---
--- Just clear current lint errors
--- @field clear boolean

--- Lint treesitter queries using installed parser, or clear lint errors.
---
--- Use |treesitter-parsers| in runtimepath to check the query file in {buf} for errors:
---
---   - verify that used nodes are valid identifiers in the grammar.
---   - verify that predicates and directives are valid.
---   - verify that top-level s-expressions are valid.
---
--- The found diagnostics are reported using |diagnostic-api|.
--- By default, the parser used for verification is determined by the containing folder
--- of the query file, e.g., if the path ends in `/lua/highlights.scm`, the parser for the
--- `lua` language will be used.
---@param buf (integer) Buffer handle
---@param opts? vim.treesitter.query.lint.Opts
function M.lint(buf, opts)
  if opts and opts.clear then
    vim.treesitter._query_linter.clear(buf)
  else
    vim.treesitter._query_linter.lint(buf, opts)
  end
end

--- Omnifunc for completing node names and predicates in treesitter queries.
---
--- Use via
---
--- ```lua
--- vim.bo.omnifunc = 'v:lua.vim.treesitter.query.omnifunc'
--- ```
---
--- @param findstart 0|1
--- @param base string
function M.omnifunc(findstart, base)
  return vim.treesitter._query_linter.omnifunc(findstart, base)
end

--- Opens a live editor to query the buffer you started from.
---
--- Can also be shown with [:EditQuery]().
---
--- If you move the cursor to a capture name ("@foo"), text matching the capture is highlighted in
--- the source buffer. The query editor is a scratch buffer, use `:write` to save it. You can find
--- example queries at `$VIMRUNTIME/queries/`.
---
--- @param lang? string language to open the query editor for. If omitted, inferred from the current buffer's filetype.
function M.edit(lang)
  assert(vim.treesitter.dev.edit_query(lang))
end

return M