refacto: split explorer module into multiple files

lua/nvim-tree/explorer/explore.lua

@@ -0,0 +1,80 @@
+local api = vim.api
+local luv = vim.loop
+
+local utils = require'nvim-tree.utils'
+local eutils = require'nvim-tree.explorer.utils'
+local builders = require'nvim-tree.explorer.node-builders'
+
+local M = {}
+
+function M.explore(nodes, cwd, parent_node, status)
+  local handle = luv.fs_scandir(cwd)
+  if type(handle) == 'string' then
+    api.nvim_err_writeln(handle)
+    return
+  end
+
+  local dirs = {}
+  local links = {}
+  local files = {}
+
+  while true do
+    local name, t = luv.fs_scandir_next(handle)
+    if not name then break end
+
+    local abs = utils.path_join({cwd, name})
+    if not eutils.should_ignore(abs) and not eutils.should_ignore_git(abs, status.files) then
+      if not t then
+        local stat = luv.fs_stat(abs)
+        t = stat and stat.type
+      end
+
+      if t == 'directory' then
+        table.insert(dirs, name)
+      elseif t == 'file' then
+        table.insert(files, name)
+      elseif t == 'link' then
+        table.insert(links, name)
+      end
+    end
+  end
+
+  local parent_node_ignored = parent_node and parent_node.git_status == '!!'
+  -- Group empty dirs
+  if parent_node and vim.g.nvim_tree_group_empty == 1 then
+    if eutils.should_group(cwd, dirs, files, links) then
+      local child_node
+      if dirs[1] then child_node = builders.folder(cwd, dirs[1], status, parent_node_ignored) end
+      if links[1] then child_node = builders.link(cwd, links[1], status, parent_node_ignored) end
+      if luv.fs_access(child_node.absolute_path, 'R') then
+        parent_node.group_next = child_node
+        child_node.git_status = parent_node.git_status
+        M.explore(nodes, child_node.absolute_path, child_node, status)
+        return
+      end
+    end
+  end
+
+  for _, dirname in ipairs(dirs) do
+    local dir = builders.folder(cwd, dirname, status, parent_node_ignored)
+    if luv.fs_access(dir.absolute_path, 'R') then
+      table.insert(nodes, dir)
+    end
+  end
+
+  for _, linkname in ipairs(links) do
+    local link = builders.link(cwd, linkname, status, parent_node_ignored)
+    if link.link_to ~= nil then
+      table.insert(nodes, link)
+    end
+  end
+
+  for _, filename in ipairs(files) do
+    local file = builders.file(cwd, filename, status, parent_node_ignored)
+    table.insert(nodes, file)
+  end
+
+  utils.merge_sort(nodes, eutils.node_comparator)
+end
+
+return M