Merge remote-tracking branch 'upstream/master' into mix_20240309HEADrahm

1 files changed, 373 insertions, 0 deletions

diff --git a/runtime/lua/vim/lsp/_folding_range.lua b/runtime/lua/vim/lsp/_folding_range.lua
new file mode 100644
index 0000000000..66eb81db6e
--- /dev/null
+++ b/runtime/lua/vim/lsp/_folding_range.lua
@@ -0,0 +1,373 @@
+local util = require('vim.lsp.util')
+local log = require('vim.lsp.log')
+local ms = require('vim.lsp.protocol').Methods
+local api = vim.api
+
+local M = {}
+
+---@class (private) vim.lsp.folding_range.BufState
+---
+---@field version? integer
+---
+--- Never use this directly, `renew()` the cached foldinfo
+--- then use on demand via `row_*` fields.
+---
+--- Index In the form of client_id -> ranges
+---@field client_ranges table<integer, lsp.FoldingRange[]?>
+---
+--- Index in the form of row -> [foldlevel, mark]
+---@field row_level table<integer, [integer, ">" | "<"?]?>
+---
+--- Index in the form of start_row -> kinds
+---@field row_kinds table<integer, table<lsp.FoldingRangeKind, true?>?>>
+---
+--- Index in the form of start_row -> collapsed_text
+---@field row_text table<integer, string?>
+
+---@type table<integer, vim.lsp.folding_range.BufState?>
+local bufstates = {}
+
+--- Renew the cached foldinfo in the buffer.
+---@param bufnr integer
+local function renew(bufnr)
+  local bufstate = assert(bufstates[bufnr])
+
+  ---@type table<integer, [integer, ">" | "<"?]?>
+  local row_level = {}
+  ---@type table<integer, table<lsp.FoldingRangeKind, true?>?>>
+  local row_kinds = {}
+  ---@type table<integer, string?>
+  local row_text = {}
+
+  for _, ranges in pairs(bufstate.client_ranges) do
+    for _, range in ipairs(ranges) do
+      local start_row = range.startLine
+      local end_row = range.endLine
+      -- Adding folds within a single line is not supported by Nvim.
+      if start_row ~= end_row then
+        row_text[start_row] = range.collapsedText
+
+        local kind = range.kind
+        if kind then
+          local kinds = row_kinds[start_row] or {}
+          kinds[kind] = true
+          row_kinds[start_row] = kinds
+        end
+
+        for row = start_row, end_row do
+          local level = row_level[row] or { 0 }
+          level[1] = level[1] + 1
+          row_level[row] = level
+        end
+        row_level[start_row][2] = '>'
+        row_level[end_row][2] = '<'
+      end
+    end
+  end
+
+  bufstate.row_level = row_level
+  bufstate.row_kinds = row_kinds
+  bufstate.row_text = row_text
+end
+
+--- Renew the cached foldinfo then force `foldexpr()` to be re-evaluated,
+--- without opening folds.
+---@param bufnr integer
+local function foldupdate(bufnr)
+  renew(bufnr)
+  for _, winid in ipairs(vim.fn.win_findbuf(bufnr)) do
+    local wininfo = vim.fn.getwininfo(winid)[1]
+    if wininfo and wininfo.tabnr == vim.fn.tabpagenr() then
+      if vim.wo[winid].foldmethod == 'expr' then
+        vim._foldupdate(winid, 0, api.nvim_buf_line_count(bufnr))
+      end
+    end
+  end
+end
+
+--- Whether `foldupdate()` is scheduled for the buffer with `bufnr`.
+---
+--- Index in the form of bufnr -> true?
+---@type table<integer, true?>
+local scheduled_foldupdate = {}
+
+--- Schedule `foldupdate()` after leaving insert mode.
+---@param bufnr integer
+local function schedule_foldupdate(bufnr)
+  if not scheduled_foldupdate[bufnr] then
+    scheduled_foldupdate[bufnr] = true
+    api.nvim_create_autocmd('InsertLeave', {
+      buffer = bufnr,
+      once = true,
+      callback = function()
+        foldupdate(bufnr)
+        scheduled_foldupdate[bufnr] = nil
+      end,
+    })
+  end
+end
+
+---@param results table<integer,{err: lsp.ResponseError?, result: lsp.FoldingRange[]?}>
+---@type lsp.MultiHandler
+local function multi_handler(results, ctx)
+  local bufnr = assert(ctx.bufnr)
+  -- Handling responses from outdated buffer only causes performance overhead.
+  if util.buf_versions[bufnr] ~= ctx.version then
+    return
+  end
+
+  local bufstate = assert(bufstates[bufnr])
+  for client_id, result in pairs(results) do
+    if result.err then
+      log.error(result.err)
+    else
+      bufstate.client_ranges[client_id] = result.result
+    end
+  end
+  bufstate.version = ctx.version
+
+  if api.nvim_get_mode().mode:match('^i') then
+    -- `foldUpdate()` is guarded in insert mode.
+    schedule_foldupdate(bufnr)
+  else
+    foldupdate(bufnr)
+  end
+end
+
+---@param result lsp.FoldingRange[]?
+---@type lsp.Handler
+local function handler(err, result, ctx)
+  multi_handler({ [ctx.client_id] = { err = err, result = result } }, ctx)
+end
+
+--- Request `textDocument/foldingRange` from the server.
+--- `foldupdate()` is scheduled once after the request is completed.
+---@param bufnr integer
+---@param client? vim.lsp.Client The client whose server supports `foldingRange`.
+local function request(bufnr, client)
+  ---@type lsp.FoldingRangeParams
+  local params = { textDocument = util.make_text_document_params(bufnr) }
+
+  if client then
+    client:request(ms.textDocument_foldingRange, params, handler, bufnr)
+    return
+  end
+
+  if not next(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange })) then
+    return
+  end
+
+  vim.lsp.buf_request_all(bufnr, ms.textDocument_foldingRange, params, multi_handler)
+end
+
+-- NOTE:
+-- `bufstate` and event hooks are interdependent:
+-- * `bufstate` needs event hooks for correctness.
+-- * event hooks require the previous `bufstate` for updates.
+-- Since they are manually created and destroyed,
+-- we ensure their lifecycles are always synchronized.
+--
+-- TODO(ofseed):
+-- 1. Implement clearing `bufstate` and event hooks
+--    when no clients in the buffer support the corresponding method.
+-- 2. Then generalize this state management to other LSP modules.
+local augroup_setup = api.nvim_create_augroup('nvim.lsp.folding_range.setup', {})
+
+--- Initialize `bufstate` and event hooks, then request folding ranges.
+--- Manage their lifecycle within this function.
+---@param bufnr integer
+---@return vim.lsp.folding_range.BufState?
+local function setup(bufnr)
+  if not api.nvim_buf_is_loaded(bufnr) then
+    return
+  end
+
+  -- Register the new `bufstate`.
+  bufstates[bufnr] = {
+    client_ranges = {},
+    row_level = {},
+    row_kinds = {},
+    row_text = {},
+  }
+
+  -- Event hooks from `buf_attach` can't be removed externally.
+  -- Hooks and `bufstate` share the same lifecycle;
+  -- they should self-destroy if `bufstate == nil`.
+  api.nvim_buf_attach(bufnr, false, {
+    -- `on_detach` also runs on buffer reload (`:e`).
+    -- Ensure `bufstate` and hooks are cleared to avoid duplication or leftover states.
+    on_detach = function()
+      bufstates[bufnr] = nil
+      api.nvim_clear_autocmds({ buffer = bufnr, group = augroup_setup })
+    end,
+    -- Reset `bufstate` and request folding ranges.
+    on_reload = function()
+      bufstates[bufnr] = {
+        client_ranges = {},
+        row_level = {},
+        row_kinds = {},
+        row_text = {},
+      }
+      request(bufnr)
+    end,
+    --- Sync changed rows with their previous foldlevels before applying new ones.
+    on_bytes = function(_, _, _, start_row, _, _, old_row, _, _, new_row, _, _)
+      if bufstates[bufnr] == nil then
+        return true
+      end
+      local row_level = bufstates[bufnr].row_level
+      if next(row_level) == nil then
+        return
+      end
+      local row = new_row - old_row
+      if row > 0 then
+        vim._list_insert(row_level, start_row, start_row + math.abs(row) - 1, { -1 })
+        -- If the previous row ends a fold,
+        -- Nvim treats the first row after consecutive `-1`s as a new fold start,
+        -- which is not the desired behavior.
+        local prev_level = row_level[start_row - 1]
+        if prev_level and prev_level[2] == '<' then
+          row_level[start_row] = { prev_level[1] - 1 }
+        end
+      elseif row < 0 then
+        vim._list_remove(row_level, start_row, start_row + math.abs(row) - 1)
+      end
+    end,
+  })
+  api.nvim_create_autocmd('LspDetach', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      if not api.nvim_buf_is_loaded(bufnr) then
+        return
+      end
+
+      ---@type integer
+      local client_id = args.data.client_id
+      bufstates[bufnr].client_ranges[client_id] = nil
+
+      ---@type vim.lsp.Client[]
+      local clients = vim
+        .iter(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange }))
+        ---@param client vim.lsp.Client
+        :filter(function(client)
+          return client.id ~= client_id
+        end)
+        :totable()
+      if #clients == 0 then
+        bufstates[bufnr] = {
+          client_ranges = {},
+          row_level = {},
+          row_kinds = {},
+          row_text = {},
+        }
+      end
+
+      foldupdate(bufnr)
+    end,
+  })
+  api.nvim_create_autocmd('LspAttach', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      local client = assert(vim.lsp.get_client_by_id(args.data.client_id))
+      if client:supports_method(vim.lsp.protocol.Methods.textDocument_foldingRange, bufnr) then
+        request(bufnr, client)
+      end
+    end,
+  })
+  api.nvim_create_autocmd('LspNotify', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      local client = assert(vim.lsp.get_client_by_id(args.data.client_id))
+      if
+        client:supports_method(ms.textDocument_foldingRange, bufnr)
+        and (
+          args.data.method == ms.textDocument_didChange
+          or args.data.method == ms.textDocument_didOpen
+        )
+      then
+        request(bufnr, client)
+      end
+    end,
+  })
+
+  request(bufnr)
+
+  return bufstates[bufnr]
+end
+
+---@param kind lsp.FoldingRangeKind
+---@param winid integer
+local function foldclose(kind, winid)
+  vim._with({ win = winid }, function()
+    local bufnr = api.nvim_win_get_buf(winid)
+    local row_kinds = bufstates[bufnr].row_kinds
+    -- Reverse traverse to ensure that the smallest ranges are closed first.
+    for row = api.nvim_buf_line_count(bufnr) - 1, 0, -1 do
+      local kinds = row_kinds[row]
+      if kinds and kinds[kind] then
+        vim.cmd(row + 1 .. 'foldclose')
+      end
+    end
+  end)
+end
+
+---@param kind lsp.FoldingRangeKind
+---@param winid? integer
+function M.foldclose(kind, winid)
+  vim.validate('kind', kind, 'string')
+  vim.validate('winid', winid, 'number', true)
+
+  winid = winid or api.nvim_get_current_win()
+  local bufnr = api.nvim_win_get_buf(winid)
+  local bufstate = bufstates[bufnr]
+  if not bufstate then
+    return
+  end
+
+  if bufstate.version == util.buf_versions[bufnr] then
+    foldclose(kind, winid)
+    return
+  end
+  -- Schedule `foldclose()` if the buffer is not up-to-date.
+
+  if not next(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange })) then
+    return
+  end
+  ---@type lsp.FoldingRangeParams
+  local params = { textDocument = util.make_text_document_params(bufnr) }
+  vim.lsp.buf_request_all(bufnr, ms.textDocument_foldingRange, params, function(...)
+    multi_handler(...)
+    foldclose(kind, winid)
+  end)
+end
+
+---@return string
+function M.foldtext()
+  local bufnr = api.nvim_get_current_buf()
+  local lnum = vim.v.foldstart
+  local row = lnum - 1
+  local bufstate = bufstates[bufnr]
+  if bufstate and bufstate.row_text[row] then
+    return bufstate.row_text[row]
+  end
+  return vim.fn.getline(lnum)
+end
+
+---@param lnum? integer
+---@return string level
+function M.foldexpr(lnum)
+  local bufnr = api.nvim_get_current_buf()
+  local bufstate = bufstates[bufnr] or setup(bufnr)
+  if not bufstate then
+    return '0'
+  end
+
+  local row = (lnum or vim.v.lnum) - 1
+  local level = bufstate.row_level[row]
+  return level and (level[2] or '') .. (level[1] or '0') or '0'
+end
+
+return M