Merge pull request #13834 from bfredl/omnilua

omnifunc for builtin lua

runtime/doc/lua.txt

@@ -1404,6 +1404,12 @@ inspect({object}, {options})                                   *vim.inspect()*
         https://github.com/kikito/inspect.lua
         https://github.com/mpeterv/vinspect
 
+lua_omnifunc({find_start}, {_})                           *vim.lua_omnifunc()*
+    Omnifunc for completing lua values from from the runtime lua interpreter,
+    similar to the builtin completion for the `:lua` command.
+
+    Activate using `set omnifunc=v:lua.vim.lua_omnifunc` in a lua buffer.
+
 notify({msg}, {level}, {opts})                                  *vim.notify()*
     Display a notification to the user.
 

runtime/doc/news.txt

@@ -192,6 +192,8 @@ The following new APIs or features were added.
   disabled by default and can be enabled by setting the
   `workspace.didChangeWatchedFiles.dynamicRegistration=true` capability.
 
+• Added an omnifunc implementation for lua, |vim.lua_omnifunc()|
+
 ==============================================================================
 CHANGED FEATURES                                                 *news-changes*
 

runtime/lua/vim/_editor.lua

@@ -42,6 +42,18 @@ for k, v in pairs({
   vim._submodules[k] = v
 end
 
+-- There are things which have special rules in vim._init_packages
+-- for legacy reasons (uri) or for performance (_inspector).
+-- most new things should go into a submodule namespace ( vim.foobar.do_thing() )
+vim._extra = {
+  uri_from_fname = true,
+  uri_from_bufnr = true,
+  uri_to_fname = true,
+  uri_to_bufnr = true,
+  show_pos = true,
+  inspect_pos = true,
+}
+
 vim.log = {
   levels = {
     TRACE = 0,
@@ -575,15 +587,13 @@ function vim._on_key(char)
 end
 
 --- Generate a list of possible completions for the string.
---- String starts with ^ and then has the pattern.
+--- String has the pattern.
 ---
 ---     1. Can we get it to just return things in the global namespace with that name prefix
 ---     2. Can we get it to return things from global namespace even with `print(` in front.
 function vim._expand_pat(pat, env)
   env = env or _G
 
-  pat = string.sub(pat, 2, #pat)
-
   if pat == '' then
     local result = vim.tbl_keys(env)
     table.sort(result)
@@ -644,7 +654,7 @@ function vim._expand_pat(pat, env)
       local mt = getmetatable(final_env)
       if mt and type(mt.__index) == 'table' then
         field = rawget(mt.__index, key)
-      elseif final_env == vim and vim._submodules[key] then
+      elseif final_env == vim and (vim._submodules[key] or vim._extra[key]) then
         field = vim[key]
       end
     end
@@ -674,6 +684,7 @@ function vim._expand_pat(pat, env)
   end
   if final_env == vim then
     insert_keys(vim._submodules)
+    insert_keys(vim._extra)
   end
 
   keys = vim.tbl_keys(keys)
@@ -745,6 +756,28 @@ vim._expand_pat_get_parts = function(lua_string)
   return parts, search_index
 end
 
+do
+  -- Ideally we should just call complete() inside omnifunc, though there are
+  -- some bugs, so fake the two-step dance for now.
+  local matches
+
+  --- Omnifunc for completing lua values from from the runtime lua interpreter,
+  --- similar to the builtin completion for the `:lua` command.
+  ---
+  --- Activate using `set omnifunc=v:lua.vim.lua_omnifunc` in a lua buffer.
+  function vim.lua_omnifunc(find_start, _)
+    if find_start == 1 then
+      local line = vim.api.nvim_get_current_line()
+      local prefix = string.sub(line, 1, vim.api.nvim_win_get_cursor(0)[2])
+      local pos
+      matches, pos = vim._expand_pat(prefix)
+      return (#matches > 0 and pos) or -1
+    else
+      return matches
+    end
+  end
+end
+
 ---Prints given arguments in human-readable format.
 ---Example:
 ---<pre>lua

src/nvim/lua/executor.c

@@ -1857,6 +1857,12 @@ int nlua_expand_pat(expand_T *xp, char *pat, int *num_results, char ***results)
   lua_getfield(lstate, -1, "_expand_pat");
   luaL_checktype(lstate, -1, LUA_TFUNCTION);
 
+  // ex expansion prepends a ^, but don't worry, it is not a regex
+  if (pat[0] != '^') {
+    return FAIL;
+  }
+  pat++;
+
   // [ vim, vim._expand_pat, buf ]
   lua_pushlstring(lstate, (const char *)pat, strlen(pat));
 

test/functional/lua/command_line_completion_spec.lua

@@ -5,7 +5,7 @@ local eq = helpers.eq
 local exec_lua = helpers.exec_lua
 
 local get_completions = function(input, env)
-  return exec_lua("return {vim._expand_pat(...)}", '^' .. input, env)
+  return exec_lua("return {vim._expand_pat(...)}", input, env)
 end
 
 local get_compl_parts = function(parts)
@@ -107,9 +107,12 @@ describe('nlua_expand_pat', function()
   end)
 
   it('should work with lazy submodules of "vim" global', function()
-    eq({{ 'inspect' }, 4 },
+    eq({{ 'inspect', 'inspect_pos' }, 4 },
        get_completions('vim.inspec'))
 
+    eq({{ 'treesitter' }, 4 },
+       get_completions('vim.treesi'))
+
     eq({{ 'set' }, 11 },
        get_completions('vim.keymap.se'))
   end)

test/functional/lua/vim_spec.lua

@@ -2900,6 +2900,29 @@ describe('lua stdlib', function()
     end)
   end)
 
+  it('vim.lua_omnifunc', function()
+    local screen = Screen.new(60,5)
+    screen:set_default_attr_ids {
+      [1] = {foreground = Screen.colors.Blue1, bold = true};
+      [2] = {background = Screen.colors.WebGray};
+      [3] = {background = Screen.colors.LightMagenta};
+      [4] = {bold = true};
+      [5] = {foreground = Screen.colors.SeaGreen, bold = true};
+    }
+    screen:attach()
+    command [[ set omnifunc=v:lua.vim.lua_omnifunc ]]
+
+    -- Note: the implementation is shared with lua command line completion.
+    -- More tests for completion in lua/command_line_completion_spec.lua
+    feed [[ivim.insp<c-x><c-o>]]
+    screen:expect{grid=[[
+      vim.inspect^                                                 |
+      {1:~  }{2: inspect        }{1:                                         }|
+      {1:~  }{3: inspect_pos    }{1:                                         }|
+      {1:~                                                           }|
+      {4:-- Omni completion (^O^N^P) }{5:match 1 of 2}                    |
+    ]]}
+  end)
 end)
 
 describe('lua: builtin modules', function()