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

12 files changed, 967 insertions, 996 deletions

diff --git a/src/nvim/eval/decode.c b/src/nvim/eval/decode.c
index 7b975ce775..94ef419bed 100644
--- a/src/nvim/eval/decode.c
+++ b/src/nvim/eval/decode.c
@@ -4,6 +4,7 @@
 #include <msgpack.h>
 #include <stddef.h>
 
+#include "klib/kvec.h"
 #include "nvim/ascii.h"
 #include "nvim/charset.h"  // vim_str2nr
 #include "nvim/eval.h"
@@ -11,7 +12,6 @@
 #include "nvim/eval/encode.h"
 #include "nvim/eval/typval.h"
 #include "nvim/globals.h"
-#include "nvim/lib/kvec.h"
 #include "nvim/macros.h"
 #include "nvim/message.h"
 #include "nvim/vim.h"  // OK, FAIL
@@ -430,7 +430,7 @@ static inline int parse_json_string(const char *const buf, const size_t buf_len,
         const char ubuf[] = { t[1], t[2], t[3], t[4] };
         t += 4;
         uvarnumber_T ch;
-        vim_str2nr((char_u *)ubuf, NULL, NULL,
+        vim_str2nr(ubuf, NULL, NULL,
                    STR2NR_HEX | STR2NR_FORCE, NULL, &ch, 4, true);
         if (ch == 0) {
           hasnul = true;
@@ -600,7 +600,7 @@ parse_json_number_check:
     // Convert integer
     varnumber_T nr;
     int num_len;
-    vim_str2nr((char_u *)s, NULL, &num_len, 0, &nr, NULL, (int)(p - s), true);
+    vim_str2nr(s, NULL, &num_len, 0, &nr, NULL, (int)(p - s), true);
     if ((int)exp_num_len != num_len) {
       semsg(_("E685: internal error: while converting number \"%.*s\" "
               "to integer vim_str2nr consumed %i bytes in place of %zu"),
diff --git a/src/nvim/eval/encode.c b/src/nvim/eval/encode.c
index bb514fba47..27d35ea24f 100644
--- a/src/nvim/eval/encode.c
+++ b/src/nvim/eval/encode.c
@@ -13,6 +13,7 @@
 #include <msgpack.h>
 #include <stddef.h>
 
+#include "klib/kvec.h"
 #include "nvim/ascii.h"
 #include "nvim/buffer_defs.h"
 #include "nvim/charset.h"  // vim_isprintc()
@@ -21,7 +22,6 @@
 #include "nvim/eval/typval.h"
 #include "nvim/eval/typval_encode.h"
 #include "nvim/garray.h"
-#include "nvim/lib/kvec.h"
 #include "nvim/macros.h"
 #include "nvim/math.h"
 #include "nvim/mbyte.h"
@@ -219,7 +219,7 @@ bool encode_vim_list_to_buf(const list_T *const list, size_t *const ret_len, cha
     }
     len++;
     if (TV_LIST_ITEM_TV(li)->vval.v_string != NULL) {
-      len += STRLEN(TV_LIST_ITEM_TV(li)->vval.v_string);
+      len += strlen(TV_LIST_ITEM_TV(li)->vval.v_string);
     }
   });
   if (len) {
@@ -281,7 +281,7 @@ int encode_read_from_list(ListReaderState *const state, char *const buf, const s
       state->offset = 0;
       state->li_length = (TV_LIST_ITEM_TV(state->li)->vval.v_string == NULL
                           ? 0
-                          : STRLEN(TV_LIST_ITEM_TV(state->li)->vval.v_string));
+                          : strlen(TV_LIST_ITEM_TV(state->li)->vval.v_string));
     }
   }
   *read_bytes = nbuf;
diff --git a/src/nvim/eval/executor.c b/src/nvim/eval/executor.c
index b461456a3a..0e0d0fe696 100644
--- a/src/nvim/eval/executor.c
+++ b/src/nvim/eval/executor.c
@@ -108,8 +108,7 @@ int eexe_mod_op(typval_T *const tv1, const typval_T *const tv2, const char *cons
         const char *tvs = tv_get_string(tv1);
         char numbuf[NUMBUFLEN];
         char *const s =
-          (char *)concat_str((const char_u *)tvs, (const char_u *)tv_get_string_buf(tv2,
-                                                                                    numbuf));
+          concat_str(tvs, tv_get_string_buf(tv2, numbuf));
         tv_clear(tv1);
         tv1->v_type = VAR_STRING;
         tv1->vval.v_string = s;
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 581f187140..a326c44371 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -195,15 +195,15 @@ int call_internal_func(const char_u *const fname, const int argcount, typval_T *
 {
   const EvalFuncDef *const fdef = find_internal_func((const char *)fname);
   if (fdef == NULL) {
-    return ERROR_UNKNOWN;
+    return FCERR_UNKNOWN;
   } else if (argcount < fdef->min_argc) {
-    return ERROR_TOOFEW;
+    return FCERR_TOOFEW;
   } else if (argcount > fdef->max_argc) {
-    return ERROR_TOOMANY;
+    return FCERR_TOOMANY;
   }
   argvars[argcount].v_type = VAR_UNKNOWN;
   fdef->func(argvars, rettv, fdef->data);
-  return ERROR_NONE;
+  return FCERR_NONE;
 }
 
 /// Invoke a method for base->method().
@@ -213,13 +213,13 @@ int call_internal_method(const char_u *const fname, const int argcount, typval_T
 {
   const EvalFuncDef *const fdef = find_internal_func((const char *)fname);
   if (fdef == NULL) {
-    return ERROR_UNKNOWN;
+    return FCERR_UNKNOWN;
   } else if (fdef->base_arg == BASE_NONE) {
-    return ERROR_NOTMETHOD;
+    return FCERR_NOTMETHOD;
   } else if (argcount + 1 < fdef->min_argc) {
-    return ERROR_TOOFEW;
+    return FCERR_TOOFEW;
   } else if (argcount + 1 > fdef->max_argc) {
-    return ERROR_TOOMANY;
+    return FCERR_TOOMANY;
   }
 
   typval_T argv[MAX_FUNC_ARGS + 1];
@@ -231,7 +231,7 @@ int call_internal_method(const char_u *const fname, const int argcount, typval_T
   argv[argcount + 1].v_type = VAR_UNKNOWN;
 
   fdef->func(argv, rettv, fdef->data);
-  return ERROR_NONE;
+  return FCERR_NONE;
 }
 
 /// @return  true for a non-zero Number and a non-empty String.
@@ -423,7 +423,7 @@ static buf_T *find_buffer(typval_T *avar)
       FOR_ALL_BUFFERS(bp) {
         if (bp->b_fname != NULL
             && (path_with_url(bp->b_fname) || bt_nofilename(bp))
-            && STRCMP(bp->b_fname, avar->vval.v_string) == 0) {
+            && strcmp(bp->b_fname, avar->vval.v_string) == 0) {
           buf = bp;
           break;
         }
@@ -840,7 +840,7 @@ static void get_col(typval_T *argvars, typval_T *rettv, bool charcol)
     if (fp->col == MAXCOL) {
       // '> can be MAXCOL, get the length of the line then
       if (fp->lnum <= curbuf->b_ml.ml_line_count) {
-        col = (colnr_T)STRLEN(ml_get(fp->lnum)) + 1;
+        col = (colnr_T)strlen(ml_get(fp->lnum)) + 1;
       } else {
         col = MAXCOL;
       }
@@ -849,11 +849,12 @@ static void get_col(typval_T *argvars, typval_T *rettv, bool charcol)
       // col(".") when the cursor is on the NUL at the end of the line
       // because of "coladd" can be seen as an extra column.
       if (virtual_active() && fp == &curwin->w_cursor) {
-        char_u *p = get_cursor_pos_ptr();
+        char *p = get_cursor_pos_ptr();
         if (curwin->w_cursor.coladd >=
-            (colnr_T)win_chartabsize(curwin, p, curwin->w_virtcol - curwin->w_cursor.coladd)) {
+            (colnr_T)win_chartabsize(curwin, p,
+                                     curwin->w_virtcol - curwin->w_cursor.coladd)) {
           int l;
-          if (*p != NUL && p[(l = utfc_ptr2len((char *)p))] == NUL) {
+          if (*p != NUL && p[(l = utfc_ptr2len(p))] == NUL) {
             col += l;
           }
         }
@@ -929,12 +930,12 @@ static void f_chdir(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   // Return the current directory
-  char_u *cwd = xmalloc(MAXPATHL);
-  if (os_dirname(cwd, MAXPATHL) != FAIL) {
+  char *cwd = xmalloc(MAXPATHL);
+  if (os_dirname((char_u *)cwd, MAXPATHL) != FAIL) {
 #ifdef BACKSLASH_IN_FILENAME
     slash_adjust(cwd);
 #endif
-    rettv->vval.v_string = (char *)vim_strsave(cwd);
+    rettv->vval.v_string = xstrdup(cwd);
   }
   xfree(cwd);
 
@@ -1033,7 +1034,7 @@ static void f_confirm(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   if (!error) {
-    rettv->vval.v_number = do_dialog(type, NULL, (char_u *)message, (char_u *)buttons, def, NULL,
+    rettv->vval.v_number = do_dialog(type, NULL, (char *)message, (char *)buttons, def, NULL,
                                      false);
   }
 }
@@ -1064,7 +1065,7 @@ static void f_count(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         const size_t len = STRLEN(expr);
 
         while (*p != NUL) {
-          if (mb_strnicmp(p, expr, len) == 0) {
+          if (mb_strnicmp((char *)p, (char *)expr, len) == 0) {
             n++;
             p += len;
           } else {
@@ -1269,7 +1270,7 @@ static void f_ctxsize(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// Otherwise use the column number as a byte offset.
 static void set_cursorpos(typval_T *argvars, typval_T *rettv, bool charcol)
 {
-  long line, col;
+  long lnum, col;
   long coladd = 0;
   bool set_curswant = true;
 
@@ -1283,7 +1284,7 @@ static void set_cursorpos(typval_T *argvars, typval_T *rettv, bool charcol)
       return;
     }
 
-    line = pos.lnum;
+    lnum = pos.lnum;
     col = pos.col;
     coladd = pos.coladd;
     if (curswant >= 0) {
@@ -1292,10 +1293,15 @@ static void set_cursorpos(typval_T *argvars, typval_T *rettv, bool charcol)
     }
   } else if ((argvars[0].v_type == VAR_NUMBER || argvars[0].v_type == VAR_STRING)
              && (argvars[1].v_type == VAR_NUMBER || argvars[1].v_type == VAR_STRING)) {
-    line = tv_get_lnum(argvars);
+    lnum = tv_get_lnum(argvars);
+    if (lnum < 0) {
+      semsg(_(e_invarg2), tv_get_string(&argvars[0]));
+    } else if (lnum == 0) {
+      lnum = curwin->w_cursor.lnum;
+    }
     col = (long)tv_get_number_chk(&argvars[1], NULL);
     if (charcol) {
-      col = buf_charidx_to_byteidx(curbuf, (linenr_T)line, (int)col) + 1;
+      col = buf_charidx_to_byteidx(curbuf, (linenr_T)lnum, (int)col) + 1;
     }
     if (argvars[2].v_type != VAR_UNKNOWN) {
       coladd = (long)tv_get_number_chk(&argvars[2], NULL);
@@ -1304,11 +1310,11 @@ static void set_cursorpos(typval_T *argvars, typval_T *rettv, bool charcol)
     emsg(_(e_invarg));
     return;
   }
-  if (line < 0 || col < 0 || coladd < 0) {
+  if (lnum < 0 || col < 0 || coladd < 0) {
     return;  // type error; errmsg already given
   }
-  if (line > 0) {
-    curwin->w_cursor.lnum = (linenr_T)line;
+  if (lnum > 0) {
+    curwin->w_cursor.lnum = (linenr_T)lnum;
   }
   if (col > 0) {
     curwin->w_cursor.col = (colnr_T)col - 1;
@@ -1343,7 +1349,7 @@ static void f_debugbreak(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   if (pid == 0) {
     emsg(_(e_invarg));
   } else {
-#ifdef WIN32
+#ifdef MSWIN
     HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, 0, pid);
 
     if (hProcess != NULL) {
@@ -1694,7 +1700,7 @@ static void f_environ(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     char c = env[i][len];
     env[i][len] = NUL;
 
-#ifdef WIN32
+#ifdef MSWIN
     // Upper-case all the keys for Windows so we can detect duplicates
     char *const key = strcase_save(str, true);
 #else
@@ -1771,7 +1777,7 @@ static void f_eventhandler(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
 /// "executable()" function
 static void f_executable(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  if (tv_check_for_string(&argvars[0]) == FAIL) {
+  if (tv_check_for_string_arg(argvars, 0) == FAIL) {
     return;
   }
 
@@ -1900,7 +1906,7 @@ static void f_win_execute(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "exepath()" function
 static void f_exepath(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  if (tv_check_for_nonempty_string(&argvars[0]) == FAIL) {
+  if (tv_check_for_nonempty_string_arg(argvars, 0) == FAIL) {
     return;
   }
 
@@ -1937,9 +1943,14 @@ static void f_exists(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       xfree(exp);
     }
   } else if (*p == '&' || *p == '+') {  // Option.
-    n = (get_option_tv(&p, NULL, true) == OK);
-    if (*skipwhite(p) != NUL) {
-      n = false;  // Trailing garbage.
+    bool working = (*p == '+');  // whether option needs to be working
+    int opt_flags;
+
+    if (find_option_end(&p, &opt_flags) != NULL) {
+      int opt_idx = findoption(p);
+      n = (opt_idx >= 0 && (!working || get_varp_scope(get_option(opt_idx), opt_flags) != NULL));
+    } else {
+      n = false;
     }
   } else if (*p == '*') {  // Internal or user defined function.
     n = function_exists(p + 1, false);
@@ -2015,10 +2026,9 @@ static void f_expand(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         options += WILD_ICASE;
       }
       if (rettv->v_type == VAR_STRING) {
-        rettv->vval.v_string = (char *)ExpandOne(&xpc, (char_u *)s, NULL, options,
-                                                 WILD_ALL);
+        rettv->vval.v_string = ExpandOne(&xpc, (char *)s, NULL, options, WILD_ALL);
       } else {
-        ExpandOne(&xpc, (char_u *)s, NULL, options, WILD_ALL_KEEP);
+        ExpandOne(&xpc, (char *)s, NULL, options, WILD_ALL_KEEP);
         tv_list_alloc_ret(rettv, xpc.xp_numfiles);
         for (int i = 0; i < xpc.xp_numfiles; i++) {
           tv_list_append_string(rettv->vval.v_list,
@@ -2209,7 +2219,7 @@ static void f_filereadable(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
 {
   const char *const p = tv_get_string(&argvars[0]);
   rettv->vval.v_number =
-    (*p && !os_isdir((const char_u *)p) && os_file_is_readable(p));
+    (*p && !os_isdir(p) && os_file_is_readable(p));
 }
 
 /// @return  0 for not writable
@@ -2436,7 +2446,7 @@ static void f_get(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       pt = argvars[0].vval.v_partial;
     } else {
       CLEAR_FIELD(fref_pt);
-      fref_pt.pt_name = (char_u *)argvars[0].vval.v_string;
+      fref_pt.pt_name = argvars[0].vval.v_string;
       pt = &fref_pt;
     }
 
@@ -2578,9 +2588,8 @@ static void get_buffer_lines(buf_T *buf, linenr_T start, linenr_T end, int retli
     }
   } else {
     rettv->v_type = VAR_STRING;
-    rettv->vval.v_string =
-      (char *)((start >= 1 && start <= buf->b_ml.ml_line_count)
-               ? vim_strsave(ml_get_buf(buf, start, false)) : NULL);
+    rettv->vval.v_string = ((start >= 1 && start <= buf->b_ml.ml_line_count)
+                            ? xstrdup(ml_get_buf(buf, start, false)) : NULL);
   }
 }
 
@@ -2720,40 +2729,6 @@ static void f_getcharsearch(typval_T *argvars, typval_T *rettv, EvalFuncData fpt
   tv_dict_add_nr(dict, S_LEN("until"), last_csearch_until());
 }
 
-/// "getcmdcompltype()" function
-static void f_getcmdcompltype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  rettv->v_type = VAR_STRING;
-  rettv->vval.v_string = (char *)get_cmdline_completion();
-}
-
-/// "getcmdline()" function
-static void f_getcmdline(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  rettv->v_type = VAR_STRING;
-  rettv->vval.v_string = (char *)get_cmdline_str();
-}
-
-/// "getcmdpos()" function
-static void f_getcmdpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  rettv->vval.v_number = get_cmdline_pos() + 1;
-}
-
-/// "getcmdscreenpos()" function
-static void f_getcmdscreenpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  rettv->vval.v_number = get_cmdline_screen_pos() + 1;
-}
-
-/// "getcmdtype()" function
-static void f_getcmdtype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  rettv->v_type = VAR_STRING;
-  rettv->vval.v_string = xmallocz(1);
-  rettv->vval.v_string[0] = (char)get_cmdline_type();
-}
-
 /// "getcmdwintype()" function
 static void f_getcmdwintype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
@@ -2921,7 +2896,7 @@ static void f_getfsize(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   FileInfo file_info;
   if (os_fileinfo(fname, &file_info)) {
     uint64_t filesize = os_fileinfo_size(&file_info);
-    if (os_isdir((const char_u *)fname)) {
+    if (os_isdir(fname)) {
       rettv->vval.v_number = 0;
     } else {
       rettv->vval.v_number = (varnumber_T)filesize;
@@ -2952,7 +2927,7 @@ static void f_getftime(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "getftype({fname})" function
 static void f_getftype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  char_u *type = NULL;
+  char *type = NULL;
   char *t;
 
   const char *fname = tv_get_string(&argvars[0]);
@@ -2978,9 +2953,9 @@ static void f_getftype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     } else {
       t = "other";
     }
-    type = vim_strsave((char_u *)t);
+    type = xstrdup(t);
   }
-  rettv->vval.v_string = (char *)type;
+  rettv->vval.v_string = type;
 }
 
 /// "getjumplist()" function
@@ -3474,11 +3449,11 @@ static void f_glob(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       options += WILD_ICASE;
     }
     if (rettv->v_type == VAR_STRING) {
-      rettv->vval.v_string = (char *)ExpandOne(&xpc, (char_u *)
-                                               tv_get_string(&argvars[0]), NULL, options,
-                                               WILD_ALL);
+      rettv->vval.v_string = ExpandOne(&xpc, (char *)
+                                       tv_get_string(&argvars[0]), NULL, options,
+                                       WILD_ALL);
     } else {
-      ExpandOne(&xpc, (char_u *)tv_get_string(&argvars[0]), NULL, options,
+      ExpandOne(&xpc, (char *)tv_get_string(&argvars[0]), NULL, options,
                 WILD_ALL_KEEP);
       tv_list_alloc_ret(rettv, xpc.xp_numfiles);
       for (int i = 0; i < xpc.xp_numfiles; i++) {
@@ -3524,7 +3499,7 @@ static void f_globpath(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   if (file != NULL && !error) {
     garray_T ga;
     ga_init(&ga, (int)sizeof(char_u *), 10);
-    globpath((char *)tv_get_string(&argvars[0]), (char_u *)file, &ga, flags);
+    globpath((char *)tv_get_string(&argvars[0]), (char *)file, &ga, flags);
 
     if (rettv->v_type == VAR_STRING) {
       rettv->vval.v_string = ga_concat_strings_sep(&ga, "\n");
@@ -3567,7 +3542,7 @@ static void f_has(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 #ifdef UNIX
     "unix",
 #endif
-#if defined(WIN32)
+#if defined(MSWIN)
     "win32",
 #endif
 #ifdef _WIN64
@@ -3882,7 +3857,7 @@ static void f_hostname(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   os_get_hostname(hostname, 256);
   rettv->v_type = VAR_STRING;
-  rettv->vval.v_string = (char *)vim_strsave((char_u *)hostname);
+  rettv->vval.v_string = xstrdup(hostname);
 }
 
 /// iconv() function
@@ -3895,17 +3870,19 @@ static void f_iconv(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   const char *const str = tv_get_string(&argvars[0]);
   char buf1[NUMBUFLEN];
-  char_u *const from = enc_canonize(enc_skip((char_u *)tv_get_string_buf(&argvars[1], buf1)));
+  char_u *const from =
+    (char_u *)enc_canonize(enc_skip((char *)tv_get_string_buf(&argvars[1], buf1)));
   char buf2[NUMBUFLEN];
-  char_u *const to = enc_canonize(enc_skip((char_u *)tv_get_string_buf(&argvars[2], buf2)));
+  char_u *const to =
+    (char_u *)enc_canonize(enc_skip((char *)tv_get_string_buf(&argvars[2], buf2)));
   vimconv.vc_type = CONV_NONE;
-  convert_setup(&vimconv, from, to);
+  convert_setup(&vimconv, (char *)from, (char *)to);
 
   // If the encodings are equal, no conversion needed.
   if (vimconv.vc_type == CONV_NONE) {
     rettv->vval.v_string = xstrdup(str);
   } else {
-    rettv->vval.v_string = (char *)string_convert(&vimconv, (char_u *)str, NULL);
+    rettv->vval.v_string = string_convert(&vimconv, (char *)str, NULL);
   }
 
   convert_setup(&vimconv, NULL, NULL);
@@ -4162,7 +4139,7 @@ static void f_invert(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "isdirectory()" function
 static void f_isdirectory(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  rettv->vval.v_number = os_isdir((const char_u *)tv_get_string(&argvars[0]));
+  rettv->vval.v_number = os_isdir(tv_get_string(&argvars[0]));
 }
 
 /// "islocked()" function
@@ -4290,7 +4267,7 @@ static void f_jobresize(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 }
 
 static const char *ignored_env_vars[] = {
-#ifndef WIN32
+#ifndef MSWIN
   "COLUMNS",
   "LINES",
   "TERMCAP",
@@ -4302,7 +4279,7 @@ static const char *ignored_env_vars[] = {
 /// According to comments in src/win/process.c of libuv, Windows has a few
 /// "essential" environment variables.
 static const char *required_env_vars[] = {
-#ifdef WIN32
+#ifdef MSWIN
   "HOMEDRIVE",
   "HOMEPATH",
   "LOGONSERVER",
@@ -4341,7 +4318,7 @@ static dict_T *create_environment(const dictitem_T *job_env, const bool clear_en
           tv_dict_item_remove(env, dv);
         }
       }
-#ifndef WIN32
+#ifndef MSWIN
       // Set COLORTERM to "truecolor" if termguicolors is set and 256
       // otherwise, but only if it was set in the parent terminal at all
       dictitem_T *dv = tv_dict_find(env, S_LEN("COLORTERM"));
@@ -4376,7 +4353,7 @@ static dict_T *create_environment(const dictitem_T *job_env, const bool clear_en
   }
 
   if (job_env) {
-#ifdef WIN32
+#ifdef MSWIN
     TV_DICT_ITER(job_env->di_tv.vval.v_dict, var, {
       // Always use upper-case keys for Windows so we detect duplicate keys
       char *const key = strcase_save((const char *)var->di_key, true);
@@ -4476,7 +4453,7 @@ static void f_jobstart(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       return;
     }
 
-#ifdef WIN32
+#ifdef MSWIN
     if (pty && overlapped) {
       semsg(_(e_invarg2),
             "job cannot have both 'pty' and 'overlapped' options set");
@@ -4489,7 +4466,7 @@ static void f_jobstart(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (new_cwd && *new_cwd != NUL) {
       cwd = new_cwd;
       // The new cwd must be a directory.
-      if (!os_isdir((const char_u *)cwd)) {
+      if (!os_isdir(cwd)) {
         semsg(_(e_invarg2), "expected valid directory");
         shell_free_argv(argv);
         return;
@@ -4706,6 +4683,20 @@ static void f_json_encode(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   rettv->vval.v_string = encode_tv2json(&argvars[0], NULL);
 }
 
+/// "keytrans()" function
+static void f_keytrans(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  rettv->v_type = VAR_STRING;
+  if (tv_check_for_string_arg(argvars, 0) == FAIL
+      || argvars[0].vval.v_string == NULL) {
+    return;
+  }
+  // Need to escape K_SPECIAL for mb_unescape().
+  char *escaped = vim_strsave_escape_ks(argvars[0].vval.v_string);
+  rettv->vval.v_string = str2special_save(escaped, true, true);
+  xfree(escaped);
+}
+
 /// "last_buffer_nr()" function.
 static void f_last_buffer_nr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
@@ -5017,9 +5008,9 @@ static void find_some_match(typval_T *const argvars, typval_T *const rettv,
         li = TV_LIST_ITEM_NEXT(l, li);
         idx++;
       } else {
-        startcol = (colnr_T)(regmatch.startp[0]
-                             + utfc_ptr2len((char *)regmatch.startp[0]) - str);
-        if (startcol > (colnr_T)len || str + startcol <= regmatch.startp[0]) {
+        startcol = (colnr_T)((char_u *)regmatch.startp[0]
+                             + utfc_ptr2len(regmatch.startp[0]) - str);
+        if (startcol > (colnr_T)len || str + startcol <= (char_u *)regmatch.startp[0]) {
           match = false;
           break;
         }
@@ -5038,8 +5029,8 @@ static void find_some_match(typval_T *const argvars, typval_T *const rettv,
 
         const size_t rd = (size_t)(regmatch.endp[0] - regmatch.startp[0]);
         TV_LIST_ITEM_TV(li1)->vval.v_string = xmemdupz((const char *)regmatch.startp[0], rd);
-        TV_LIST_ITEM_TV(li3)->vval.v_number = (varnumber_T)(regmatch.startp[0] - expr);
-        TV_LIST_ITEM_TV(li4)->vval.v_number = (varnumber_T)(regmatch.endp[0] - expr);
+        TV_LIST_ITEM_TV(li3)->vval.v_number = (varnumber_T)((char_u *)regmatch.startp[0] - expr);
+        TV_LIST_ITEM_TV(li4)->vval.v_number = (varnumber_T)(regmatch.endp[0] - (char *)expr);
         if (l != NULL) {
           TV_LIST_ITEM_TV(li2)->vval.v_number = (varnumber_T)idx;
         }
@@ -5074,10 +5065,10 @@ static void find_some_match(typval_T *const argvars, typval_T *const rettv,
         } else {
           if (type == kSomeMatch) {
             rettv->vval.v_number =
-              (varnumber_T)(regmatch.startp[0] - str);
+              (varnumber_T)((char_u *)regmatch.startp[0] - str);
           } else {
             rettv->vval.v_number =
-              (varnumber_T)(regmatch.endp[0] - str);
+              (varnumber_T)(regmatch.endp[0] - (char *)str);
           }
           rettv->vval.v_number += (varnumber_T)(str - expr);
         }
@@ -5416,7 +5407,7 @@ static void f_nextnonblank(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
       lnum = 0;
       break;
     }
-    if (*skipwhite((char *)ml_get(lnum)) != NUL) {
+    if (*skipwhite(ml_get(lnum)) != NUL) {
       break;
     }
   }
@@ -5474,11 +5465,11 @@ static void f_pathshorten(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   rettv->v_type = VAR_STRING;
-  const char_u *p = (char_u *)tv_get_string_chk(&argvars[0]);
+  const char *p = tv_get_string_chk(&argvars[0]);
   if (p == NULL) {
     rettv->vval.v_string = NULL;
   } else {
-    rettv->vval.v_string = (char *)vim_strsave(p);
+    rettv->vval.v_string = xstrdup(p);
     shorten_dir_len((char_u *)rettv->vval.v_string, trim_len);
   }
 }
@@ -5504,7 +5495,7 @@ static void f_prevnonblank(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   if (lnum < 1 || lnum > curbuf->b_ml.ml_line_count) {
     lnum = 0;
   } else {
-    while (lnum >= 1 && *skipwhite((char *)ml_get(lnum)) == NUL) {
+    while (lnum >= 1 && *skipwhite(ml_get(lnum)) == NUL) {
       lnum--;
     }
   }
@@ -5596,7 +5587,7 @@ static void f_prompt_getprompt(typval_T *argvars, typval_T *rettv, EvalFuncData
     return;
   }
 
-  rettv->vval.v_string = (char *)vim_strsave(buf_prompt_text(buf));
+  rettv->vval.v_string = xstrdup(buf_prompt_text(buf));
 }
 
 /// "prompt_setprompt({buffer}, {text})" function
@@ -5900,9 +5891,9 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   bool binary = false;
   bool blob = false;
   FILE *fd;
-  char_u buf[(IOSIZE/256) * 256];  // rounded to avoid odd + 1
+  char buf[(IOSIZE/256) * 256];    // rounded to avoid odd + 1
   int io_size = sizeof(buf);
-  char_u *prev = NULL;             // previously read bytes, if any
+  char *prev = NULL;               // previously read bytes, if any
   long prevlen  = 0;               // length of data in prev
   long prevsize = 0;               // size of prev buffer
   long maxline  = MAXLNUM;
@@ -5922,7 +5913,7 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   // their own about CR-LF conversion.
   const char *const fname = tv_get_string(&argvars[0]);
 
-  if (os_isdir((const char_u *)fname)) {
+  if (os_isdir(fname)) {
     semsg(_(e_isadir2), fname);
     return;
   }
@@ -5953,13 +5944,13 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     // - an incomplete line gets written
     // - a "binary" file gets an empty line at the end if it ends in a
     //   newline.
-    char_u *p;  // Position in buf.
-    char_u *start;  // Start of current line.
+    char *p;  // Position in buf.
+    char *start;  // Start of current line.
     for (p = buf, start = buf;
          p < buf + readlen || (readlen <= 0 && (prevlen > 0 || binary));
          p++) {
       if (*p == '\n' || readlen <= 0) {
-        char_u *s  = NULL;
+        char *s  = NULL;
         size_t len = (size_t)(p - start);
 
         // Finished a line.  Remove CRs before NL.
@@ -5976,7 +5967,7 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         }
         if (prevlen == 0) {
           assert(len < INT_MAX);
-          s = vim_strnsave(start, len);
+          s = xstrnsave(start, len);
         } else {
           // Change "prev" buffer to be the right size.  This way
           // the bytes are only copied once, and very long lines are
@@ -5991,7 +5982,7 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         tv_list_append_owned_tv(l, (typval_T) {
           .v_type = VAR_STRING,
           .v_lock = VAR_UNLOCKED,
-          .vval.v_string = (char *)s,
+          .vval.v_string = s,
         });
 
         start = p + 1;  // Step over newline.
@@ -6011,18 +6002,18 @@ static void f_readfile(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         *p = '\n';
         // Check for utf8 "bom"; U+FEFF is encoded as EF BB BF.  Do this
         // when finding the BF and check the previous two bytes.
-      } else if (*p == 0xbf && !binary) {
+      } else if ((uint8_t)(*p) == 0xbf && !binary) {
         // Find the two bytes before the 0xbf.  If p is at buf, or buf + 1,
         // these may be in the "prev" string.
-        char_u back1 = p >= buf + 1 ? p[-1]
+        char back1 = p >= buf + 1 ? p[-1]
                                     : prevlen >= 1 ? prev[prevlen - 1] : NUL;
-        char_u back2 = p >= buf + 2 ? p[-2]
+        char back2 = p >= buf + 2 ? p[-2]
                                     : p == buf + 1 && prevlen >= 1 ? prev[prevlen - 1]
                                                                    : prevlen >=
-                       2 ? prev[prevlen - 2] : NUL;
+                     2 ? prev[prevlen - 2] : NUL;
 
-        if (back2 == 0xef && back1 == 0xbb) {
-          char_u *dest = p - 2;
+        if ((uint8_t)back2 == 0xef && (uint8_t)back1 == 0xbb) {
+          char *dest = p - 2;
 
           // Usually a BOM is at the beginning of a file, and so at
           // the beginning of a line; then we can just step over it.
@@ -6258,8 +6249,8 @@ static void f_rename(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     rettv->vval.v_number = -1;
   } else {
     char buf[NUMBUFLEN];
-    rettv->vval.v_number = vim_rename((const char_u *)tv_get_string(&argvars[0]),
-                                      (const char_u *)tv_get_string_buf(&argvars[1], buf));
+    rettv->vval.v_number = vim_rename(tv_get_string(&argvars[0]),
+                                      tv_get_string_buf(&argvars[1], buf));
   }
 }
 
@@ -6305,7 +6296,7 @@ static void f_resolve(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   rettv->v_type = VAR_STRING;
   const char *fname = tv_get_string(&argvars[0]);
-#ifdef WIN32
+#ifdef MSWIN
   char *v = os_resolve_shortcut(fname);
   if (v == NULL) {
     if (os_is_reparse_point_include(fname)) {
@@ -6374,7 +6365,7 @@ static void f_resolve(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         if (*q != NUL) {
           cpy = remain;
           remain = (remain
-                    ? (char *)concat_str((char_u *)q - 1, (char_u *)remain)
+                    ? concat_str(q - 1, remain)
                     : xstrdup(q - 1));
           xfree(cpy);
           q[-1] = NUL;
@@ -6433,7 +6424,7 @@ static void f_resolve(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
                        && (p[2] == NUL
                            || vim_ispathsep(p[2])))))) {
         // Prepend "./".
-        cpy = (char *)concat_str((const char_u *)"./", (const char_u *)p);
+        cpy = concat_str("./", p);
         xfree(p);
         p = cpy;
       } else if (!is_relative_to_current) {
@@ -6517,8 +6508,8 @@ static void f_reduce(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   funcexe_T funcexe = FUNCEXE_INIT;
-  funcexe.evaluate = true;
-  funcexe.partial = partial;
+  funcexe.fe_evaluate = true;
+  funcexe.fe_partial = partial;
 
   typval_T initial;
   typval_T argv[3];
@@ -7070,7 +7061,7 @@ static void f_screenchars(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     return;
   }
   int pcc[MAX_MCO];
-  int c = utfc_ptr2char(grid->chars[grid->line_offset[row] + (size_t)col], pcc);
+  int c = utfc_ptr2char((char *)grid->chars[grid->line_offset[row] + (size_t)col], pcc);
   int composing_len = 0;
   while (pcc[composing_len] != 0) {
     composing_len++;
@@ -7090,32 +7081,6 @@ static void f_screencol(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   rettv->vval.v_number = ui_current_col() + 1;
 }
 
-/// "screenpos({winid}, {lnum}, {col})" function
-static void f_screenpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  tv_dict_alloc_ret(rettv);
-  dict_T *dict = rettv->vval.v_dict;
-
-  win_T *wp = find_win_by_nr_or_id(&argvars[0]);
-  if (wp == NULL) {
-    return;
-  }
-
-  pos_T pos = {
-    .lnum   = (linenr_T)tv_get_number(&argvars[1]),
-    .col    = (colnr_T)tv_get_number(&argvars[2]) - 1,
-    .coladd = 0
-  };
-  int row = 0;
-  int scol = 0, ccol = 0, ecol = 0;
-  textpos2screenpos(wp, &pos, &row, &scol, &ccol, &ecol, false);
-
-  tv_dict_add_nr(dict, S_LEN("row"), row);
-  tv_dict_add_nr(dict, S_LEN("col"), scol);
-  tv_dict_add_nr(dict, S_LEN("curscol"), ccol);
-  tv_dict_add_nr(dict, S_LEN("endcol"), ecol);
-}
-
 /// "screenrow()" function
 static void f_screenrow(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
@@ -7138,7 +7103,7 @@ static void f_screenstring(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
     return;
   }
 
-  rettv->vval.v_string = (char *)vim_strsave(grid->chars[grid->line_offset[row] + (size_t)col]);
+  rettv->vval.v_string = xstrdup((char *)grid->chars[grid->line_offset[row] + (size_t)col]);
 }
 
 /// "search()" function
@@ -7603,7 +7568,7 @@ static void f_setcharsearch(typval_T *argvars, typval_T *rettv, EvalFuncData fpt
     char_u *const csearch = (char_u *)tv_dict_get_string(d, "char", false);
     if (csearch != NULL) {
       int pcc[MAX_MCO];
-      const int c = utfc_ptr2char(csearch, pcc);
+      const int c = utfc_ptr2char((char *)csearch, pcc);
       set_last_csearch(c, csearch, utfc_ptr2len((char *)csearch));
     }
 
@@ -7619,16 +7584,6 @@ static void f_setcharsearch(typval_T *argvars, typval_T *rettv, EvalFuncData fpt
   }
 }
 
-/// "setcmdpos()" function
-static void f_setcmdpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
-{
-  const int pos = (int)tv_get_number(&argvars[0]) - 1;
-
-  if (pos >= 0) {
-    rettv->vval.v_number = set_cmdline_pos(pos);
-  }
-}
-
 /// "setcursorcharpos" function
 static void f_setcursorcharpos(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
@@ -7851,7 +7806,7 @@ free_lstval:
     if (strval == NULL) {
       return;
     }
-    write_reg_contents_ex(regname, (const char_u *)strval, (ssize_t)STRLEN(strval),
+    write_reg_contents_ex(regname, strval, (ssize_t)strlen(strval),
                           append, yank_type, (colnr_T)block_len);
   }
   if (pointreg != 0) {
@@ -8093,7 +8048,7 @@ static void f_spellbadword(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
     // Find the start and length of the badly spelled word.
     len = spell_move_to(curwin, FORWARD, true, true, &attr);
     if (len != 0) {
-      word = (char *)get_cursor_pos_ptr();
+      word = get_cursor_pos_ptr();
       curwin->w_set_curswant = true;
     }
   } else if (*curbuf->b_s.b_p_spl != NUL) {
@@ -8236,11 +8191,11 @@ static void f_split(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         break;
       }
       // Advance to just after the match.
-      if (regmatch.endp[0] > (char_u *)str) {
+      if (regmatch.endp[0] > str) {
         col = 0;
       } else {
         // Don't get stuck at the same match.
-        col = utfc_ptr2len((char *)regmatch.endp[0]);
+        col = utfc_ptr2len(regmatch.endp[0]);
       }
       str = (const char *)regmatch.endp[0];
     }
@@ -8345,7 +8300,7 @@ static void f_str2nr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     break;
   }
   varnumber_T n;
-  vim_str2nr(p, NULL, NULL, what, &n, NULL, 0, false);
+  vim_str2nr((char *)p, NULL, NULL, what, &n, NULL, 0, false);
   // Text after the number is silently ignored.
   if (isneg) {
     rettv->vval.v_number = -n;
@@ -8375,13 +8330,12 @@ static void f_strftime(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     rettv->vval.v_string = xstrdup(_("(Invalid)"));
   } else {
     vimconv_T conv;
-    char_u *enc;
 
     conv.vc_type = CONV_NONE;
-    enc = enc_locale();
-    convert_setup(&conv, (char_u *)p_enc, enc);
+    char *enc = (char *)enc_locale();
+    convert_setup(&conv, p_enc, enc);
     if (conv.vc_type != CONV_NONE) {
-      p = (char *)string_convert(&conv, (char_u *)p, NULL);
+      p = string_convert(&conv, p, NULL);
     }
     char result_buf[256];
     if (p != NULL) {
@@ -8393,9 +8347,9 @@ static void f_strftime(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (conv.vc_type != CONV_NONE) {
       xfree(p);
     }
-    convert_setup(&conv, enc, (char_u *)p_enc);
+    convert_setup(&conv, enc, p_enc);
     if (conv.vc_type != CONV_NONE) {
-      rettv->vval.v_string = (char *)string_convert(&conv, (char_u *)result_buf, NULL);
+      rettv->vval.v_string = string_convert(&conv, result_buf, NULL);
     } else {
       rettv->vval.v_string = xstrdup(result_buf);
     }
@@ -8421,7 +8375,7 @@ static void f_strgetchar(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     return;
   }
 
-  const size_t len = STRLEN(str);
+  const size_t len = strlen(str);
   size_t byteidx = 0;
 
   while (charidx >= 0 && byteidx < len) {
@@ -8512,7 +8466,7 @@ static void f_strdisplaywidth(typval_T *argvars, typval_T *rettv, EvalFuncData f
     col = (int)tv_get_number(&argvars[1]);
   }
 
-  rettv->vval.v_number = (varnumber_T)(linetabsize_col(col, (char_u *)s) - col);
+  rettv->vval.v_number = (varnumber_T)(linetabsize_col(col, (char *)s) - col);
 }
 
 /// "strwidth()" function
@@ -8527,7 +8481,7 @@ static void f_strwidth(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 static void f_strcharpart(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   const char *const p = tv_get_string(&argvars[0]);
-  const size_t slen = STRLEN(p);
+  const size_t slen = strlen(p);
 
   int nbyte = 0;
   bool error = false;
@@ -8638,10 +8592,10 @@ static void f_strptime(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   vimconv_T conv = {
     .vc_type = CONV_NONE,
   };
-  char_u *enc = enc_locale();
-  convert_setup(&conv, (char_u *)p_enc, enc);
+  char *enc = (char *)enc_locale();
+  convert_setup(&conv, p_enc, enc);
   if (conv.vc_type != CONV_NONE) {
-    fmt = (char *)string_convert(&conv, (char_u *)fmt, NULL);
+    fmt = string_convert(&conv, fmt, NULL);
   }
   if (fmt == NULL
       || os_strptime(str, fmt, &tmval) == NULL
@@ -8667,7 +8621,7 @@ static void f_strridx(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     return;  // Type error; errmsg already given.
   }
 
-  const size_t haystack_len = STRLEN(haystack);
+  const size_t haystack_len = strlen(haystack);
   ptrdiff_t end_idx;
   if (argvars[2].v_type != VAR_UNKNOWN) {
     // Third argument: upper limit for index.
@@ -8729,7 +8683,7 @@ static void f_submatch(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   if (retList == 0) {
     rettv->v_type = VAR_STRING;
-    rettv->vval.v_string = (char *)reg_submatch(no);
+    rettv->vval.v_string = reg_submatch(no);
   } else {
     rettv->v_type = VAR_LIST;
     rettv->vval.v_list = reg_submatch_list(no);
@@ -8782,7 +8736,7 @@ static void f_swapname(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       || buf->b_ml.ml_mfp->mf_fname == NULL) {
     rettv->vval.v_string = NULL;
   } else {
-    rettv->vval.v_string = (char *)vim_strsave(buf->b_ml.ml_mfp->mf_fname);
+    rettv->vval.v_string = xstrdup(buf->b_ml.ml_mfp->mf_fname);
   }
 }
 
@@ -8798,7 +8752,7 @@ static void f_synID(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   int id = 0;
   if (!transerr && lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count
-      && col >= 0 && (size_t)col < STRLEN(ml_get(lnum))) {
+      && col >= 0 && (size_t)col < strlen(ml_get(lnum))) {
     id = syn_get_id(curwin, lnum, col, trans, NULL, false);
   }
 
@@ -8864,7 +8818,7 @@ static void f_synIDattr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     }
     break;
   case 'u':
-    if (STRLEN(what) >= 9) {
+    if (strlen(what) >= 9) {
       if (TOLOWER_ASC(what[5]) == 'l') {
         // underline
         p = highlight_has_attr(id, HL_UNDERLINE, modec);
@@ -8923,7 +8877,7 @@ static void f_synconcealed(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
   CLEAR_FIELD(str);
 
   if (lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count && col >= 0
-      && (size_t)col <= STRLEN(ml_get(lnum)) && curwin->w_p_cole > 0) {
+      && (size_t)col <= strlen(ml_get(lnum)) && curwin->w_p_cole > 0) {
     (void)syn_get_id(curwin, lnum, col, false, NULL, false);
     syntax_flags = get_syntax_info(&matchid);
 
@@ -8960,7 +8914,7 @@ static void f_synstack(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   if (lnum >= 1
       && lnum <= curbuf->b_ml.ml_line_count
       && col >= 0
-      && (size_t)col <= STRLEN(ml_get(lnum))) {
+      && (size_t)col <= strlen(ml_get(lnum))) {
     tv_list_alloc_ret(rettv, kListLenMayKnow);
     (void)syn_get_id(curwin, lnum, col, false, NULL, true);
 
@@ -9112,7 +9066,7 @@ static void f_tagfiles(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   bool first = true;
   tagname_T tn;
-  while (get_tagfname(&tn, first, (char_u *)fname) == OK) {
+  while (get_tagfname(&tn, first, fname) == OK) {
     tv_list_append_string(rettv->vval.v_list, fname, -1);
     first = false;
   }
@@ -9143,7 +9097,7 @@ static void f_taglist(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 static void f_tempname(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   rettv->v_type = VAR_STRING;
-  rettv->vval.v_string = (char *)vim_tempname();
+  rettv->vval.v_string = vim_tempname();
 }
 
 /// "termopen(cmd[, cwd])" function
@@ -9190,7 +9144,7 @@ static void f_termopen(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (new_cwd && *new_cwd != NUL) {
       cwd = new_cwd;
       // The new cwd must be a directory.
-      if (!os_isdir((const char_u *)cwd)) {
+      if (!os_isdir(cwd)) {
         semsg(_(e_invarg2), "expected valid directory");
         shell_free_argv(argv);
         return;
@@ -9458,10 +9412,10 @@ static void f_trim(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   char buf1[NUMBUFLEN];
   char buf2[NUMBUFLEN];
-  const char_u *head = (const char_u *)tv_get_string_buf_chk(&argvars[0], buf1);
-  const char_u *mask = NULL;
-  const char_u *prev;
-  const char_u *p;
+  const char *head = tv_get_string_buf_chk(&argvars[0], buf1);
+  const char *mask = NULL;
+  const char *prev;
+  const char *p;
   int dir = 0;
 
   rettv->v_type = VAR_STRING;
@@ -9476,7 +9430,7 @@ static void f_trim(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   }
 
   if (argvars[1].v_type == VAR_STRING) {
-    mask = (const char_u *)tv_get_string_buf_chk(&argvars[1], buf2);
+    mask = tv_get_string_buf_chk(&argvars[1], buf2);
     if (argvars[2].v_type != VAR_UNKNOWN) {
       bool error = false;
       // leading or trailing characters to trim
@@ -9514,7 +9468,7 @@ static void f_trim(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     }
   }
 
-  const char_u *tail = head + STRLEN(head);
+  const char *tail = head + strlen(head);
   if (dir == 0 || dir == 2) {
     // Trim trailing characters
     for (; tail > head; tail = prev) {
@@ -9537,7 +9491,7 @@ static void f_trim(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       }
     }
   }
-  rettv->vval.v_string = (char *)vim_strnsave(head, (size_t)(tail - head));
+  rettv->vval.v_string = xstrnsave(head, (size_t)(tail - head));
 }
 
 /// "type(expr)" function
@@ -9622,7 +9576,7 @@ static void f_virtcol(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     if (fp->col < 0) {
       fp->col = 0;
     } else {
-      const size_t len = STRLEN(ml_get(fp->lnum));
+      const size_t len = strlen(ml_get(fp->lnum));
       if (fp->col > (colnr_T)len) {
         fp->col = (colnr_T)len;
       }
@@ -9637,12 +9591,12 @@ static void f_virtcol(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "visualmode()" function
 static void f_visualmode(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  char_u str[2];
+  char str[2];
 
   rettv->v_type = VAR_STRING;
-  str[0] = (char_u)curbuf->b_visual_mode_eval;
+  str[0] = (char)curbuf->b_visual_mode_eval;
   str[1] = NUL;
-  rettv->vval.v_string = (char *)vim_strsave(str);
+  rettv->vval.v_string = xstrdup(str);
 
   // A non-zero number or non-empty string argument: reset mode.
   if (non_zero_arg(&argvars[0])) {
@@ -9681,7 +9635,7 @@ static void f_win_gettype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   if (argvars[0].v_type != VAR_UNKNOWN) {
     wp = find_win_by_nr_or_id(&argvars[0]);
     if (wp == NULL) {
-      rettv->vval.v_string = (char *)vim_strsave((char_u *)"unknown");
+      rettv->vval.v_string = xstrdup("unknown");
       return;
     }
   }
@@ -9701,7 +9655,19 @@ static void f_win_gettype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "win_gotoid()" function
 static void f_win_gotoid(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  rettv->vval.v_number = win_gotoid(argvars);
+  int id = (int)tv_get_number(&argvars[0]);
+
+  if (cmdwin_type != 0) {
+    emsg(_(e_cmdwin));
+    return;
+  }
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (wp->handle == id) {
+      goto_tabpage_win(tp, wp);
+      rettv->vval.v_number = 1;
+      return;
+    }
+  }
 }
 
 /// "win_id2tabwin()" function
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index 152c2eff8f..a0b06aaaf4 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -40,6 +40,13 @@
 # include "eval/typval.c.generated.h"
 #endif
 
+static char e_string_required_for_argument_nr[]
+  = N_("E1174: String required for argument %d");
+static char e_non_empty_string_required_for_argument_nr[]
+  = N_("E1142: Non-empty string required for argument %d");
+static char e_number_required_for_argument_nr[]
+  = N_("E1210: Number required for argument %d");
+
 bool tv_in_free_unref_items = false;
 
 // TODO(ZyX-I): Remove DICT_MAXNEST, make users be non-recursive instead
@@ -1016,7 +1023,7 @@ static int item_compare(const void *s1, const void *s2, bool keep_zero)
     if (sortinfo->item_compare_lc) {
       res = strcoll(p1, p2);
     } else {
-      res = sortinfo->item_compare_ic ? STRICMP(p1, p2): STRCMP(p1, p2);
+      res = sortinfo->item_compare_ic ? STRICMP(p1, p2): strcmp(p1, p2);
     }
   } else {
     double n1, n2;
@@ -1079,9 +1086,9 @@ static int item_compare2(const void *s1, const void *s2, bool keep_zero)
 
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this
   funcexe_T funcexe = FUNCEXE_INIT;
-  funcexe.evaluate = true;
-  funcexe.partial = partial;
-  funcexe.selfdict = sortinfo->item_compare_selfdict;
+  funcexe.fe_evaluate = true;
+  funcexe.fe_partial = partial;
+  funcexe.fe_selfdict = sortinfo->item_compare_selfdict;
   res = call_func(func_name, -1, &rettv, 2, argv, &funcexe);
   tv_clear(&argv[0]);
   tv_clear(&argv[1]);
@@ -1242,14 +1249,12 @@ static void do_sort_uniq(typval_T *argvars, typval_T *rettv, bool sort)
         item_compare_func_ptr = item_compare_keeping_zero;
       }
 
-      int idx = 0;
       for (listitem_T *li = TV_LIST_ITEM_NEXT(l, tv_list_first(l))
            ; li != NULL;) {
         listitem_T *const prev_li = TV_LIST_ITEM_PREV(l, li);
         if (item_compare_func_ptr(&prev_li, &li) == 0) {
           li = tv_list_item_remove(l, li);
         } else {
-          idx++;
           li = TV_LIST_ITEM_NEXT(l, li);
         }
         if (info.item_compare_func_err) {  // -V547
@@ -1568,7 +1573,7 @@ bool tv_callback_equal(const Callback *cb1, const Callback *cb2)
   }
   switch (cb1->type) {
   case kCallbackFuncref:
-    return STRCMP(cb1->data.funcref, cb2->data.funcref) == 0;
+    return strcmp(cb1->data.funcref, cb2->data.funcref) == 0;
   case kCallbackPartial:
     // FIXME: this is inconsistent with tv_equal but is needed for precision
     // maybe change dictwatcheradd to return a watcher id instead?
@@ -1774,7 +1779,7 @@ void tv_dict_watcher_notify(dict_T *const dict, const char *const key, typval_T
     tv_dict_add(argv[2].vval.v_dict, v);
   }
 
-  if (oldtv) {
+  if (oldtv && oldtv->v_type != VAR_UNKNOWN) {
     dictitem_T *const v = tv_dict_item_alloc_len(S_LEN("old"));
     tv_copy(oldtv, &v->di_tv);
     tv_dict_add(argv[2].vval.v_dict, v);
@@ -2533,7 +2538,7 @@ dict_T *tv_dict_copy(const vimconv_T *const conv, dict_T *const orig, const bool
       new_di = tv_dict_item_alloc((const char *)di->di_key);
     } else {
       size_t len = STRLEN(di->di_key);
-      char *const key = (char *)string_convert(conv, di->di_key, &len);
+      char *const key = (char *)string_convert(conv, (char *)di->di_key, &len);
       if (key == NULL) {
         new_di = tv_dict_item_alloc_len((const char *)di->di_key, len);
       } else {
@@ -2777,7 +2782,7 @@ static void tv_dict_list(typval_T *const tv, typval_T *const rettv, const DictLi
     switch (what) {
       case kDictListKeys:
         tv_item.v_type = VAR_STRING;
-        tv_item.vval.v_string = (char *)vim_strsave(di->di_key);
+        tv_item.vval.v_string = xstrdup((char *)di->di_key);
         break;
       case kDictListValues:
         tv_copy(&di->di_tv, &tv_item);
@@ -3717,8 +3722,7 @@ varnumber_T tv_get_number_chk(const typval_T *const tv, bool *const ret_error)
   case VAR_STRING: {
     varnumber_T n = 0;
     if (tv->vval.v_string != NULL) {
-      vim_str2nr((char_u *)tv->vval.v_string, NULL, NULL, STR2NR_ALL, &n, NULL, 0,
-                 false);
+      vim_str2nr(tv->vval.v_string, NULL, NULL, STR2NR_ALL, &n, NULL, 0, false);
     }
     return n;
   }
@@ -3746,9 +3750,11 @@ varnumber_T tv_get_number_chk(const typval_T *const tv, bool *const ret_error)
 linenr_T tv_get_lnum(const typval_T *const tv)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
+  const int did_emsg_before = did_emsg;
   linenr_T lnum = (linenr_T)tv_get_number_chk(tv, NULL);
-  if (lnum == 0) {  // No valid number, try using same function as line() does.
+  if (lnum <= 0 && did_emsg_before == did_emsg && tv->v_type != VAR_NUMBER) {
     int fnum;
+    // No valid number, try using same function as line() does.
     pos_T *const fp = var2fpos(tv, true, &fnum, false);
     if (fp != NULL) {
       lnum = fp->lnum;
@@ -3801,31 +3807,50 @@ float_T tv_get_float(const typval_T *const tv)
   return 0;
 }
 
-// Give an error and return FAIL unless "tv" is a string.
-int tv_check_for_string(const typval_T *const tv)
+/// Give an error and return FAIL unless "args[idx]" is a string.
+int tv_check_for_string_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv->v_type != VAR_STRING) {
-    emsg(_(e_stringreq));
+  if (args[idx].v_type != VAR_STRING) {
+    semsg(_(e_string_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;
 }
 
-// Give an error and return FAIL unless "tv" is a non-empty string.
-int tv_check_for_nonempty_string(const typval_T *const tv)
+/// Give an error and return FAIL unless "args[idx]" is a non-empty string.
+int tv_check_for_nonempty_string_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv_check_for_string(tv) == FAIL) {
+  if (tv_check_for_string_arg(args, idx) == FAIL) {
+    return FAIL;
+  }
+  if (args[idx].vval.v_string == NULL || *args[idx].vval.v_string == NUL) {
+    semsg(_(e_non_empty_string_required_for_argument_nr), idx + 1);
     return FAIL;
   }
-  if (tv->vval.v_string == NULL || *tv->vval.v_string == NUL) {
-    emsg(_(e_non_empty_string_required));
+  return OK;
+}
+
+/// Give an error and return FAIL unless "args[idx]" is a number.
+int tv_check_for_number_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  if (args[idx].v_type != VAR_NUMBER) {
+    semsg(_(e_number_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;
 }
 
+/// Check for an optional number argument at "idx"
+int tv_check_for_opt_number_arg(const typval_T *const args, const int idx)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  return (args[idx].v_type == VAR_UNKNOWN
+          || tv_check_for_number_arg(args, idx) != FAIL) ? OK : FAIL;
+}
+
 /// Get the string value of a "stringish" VimL object.
 ///
 /// @param[in]  tv  Object to get value of.
diff --git a/src/nvim/eval/typval.h b/src/nvim/eval/typval.h
index 8177d01f90..0a4adc1f53 100644
--- a/src/nvim/eval/typval.h
+++ b/src/nvim/eval/typval.h
@@ -2,415 +2,19 @@
 #define NVIM_EVAL_TYPVAL_H
 
 #include <assert.h>
-#include <inttypes.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <string.h>
 
+#include "nvim/eval/typval_defs.h"
 #include "nvim/func_attr.h"
-#include "nvim/garray.h"
 #include "nvim/gettext.h"
-#include "nvim/hashtab.h"
-#include "nvim/lib/queue.h"
 #include "nvim/macros.h"
 #include "nvim/mbyte_defs.h"
 #include "nvim/message.h"
-#include "nvim/pos.h"      // for linenr_T
-#include "nvim/types.h"
-#ifdef LOG_LIST_ACTIONS
-# include "nvim/memory.h"
-#endif
-
-/// Type used for VimL VAR_NUMBER values
-typedef int64_t varnumber_T;
-typedef uint64_t uvarnumber_T;
-
-/// Refcount for dict or list that should not be freed
-enum { DO_NOT_FREE_CNT = (INT_MAX / 2), };
-
-/// Additional values for tv_list_alloc() len argument
-enum ListLenSpecials {
-  /// List length is not known in advance
-  ///
-  /// To be used when there is neither a way to know how many elements will be
-  /// needed nor are any educated guesses.
-  kListLenUnknown = -1,
-  /// List length *should* be known, but is actually not
-  ///
-  /// All occurrences of this value should be eventually removed. This is for
-  /// the case when the only reason why list length is not known is that it
-  /// would be hard to code without refactoring, but refactoring is needed.
-  kListLenShouldKnow = -2,
-  /// List length may be known in advance, but it requires too much effort
-  ///
-  /// To be used when it looks impractical to determine list length.
-  kListLenMayKnow = -3,
-};
-
-/// Maximal possible value of varnumber_T variable
-#define VARNUMBER_MAX INT64_MAX
-#define UVARNUMBER_MAX UINT64_MAX
-
-/// Minimal possible value of varnumber_T variable
-#define VARNUMBER_MIN INT64_MIN
-
-/// %d printf format specifier for varnumber_T
-#define PRIdVARNUMBER PRId64
-
-typedef struct listvar_S list_T;
-typedef struct dictvar_S dict_T;
-typedef struct partial_S partial_T;
-typedef struct blobvar_S blob_T;
-
-typedef struct ufunc ufunc_T;
-
-typedef enum {
-  kCallbackNone = 0,
-  kCallbackFuncref,
-  kCallbackPartial,
-  kCallbackLua,
-} CallbackType;
-
-typedef struct {
-  union {
-    char *funcref;
-    partial_T *partial;
-    LuaRef luaref;
-  } data;
-  CallbackType type;
-} Callback;
-
-#define CALLBACK_INIT { .type = kCallbackNone }
-#define CALLBACK_NONE ((Callback)CALLBACK_INIT)
-
-/// Structure holding dictionary watcher
-typedef struct dict_watcher {
-  Callback callback;
-  char *key_pattern;
-  size_t key_pattern_len;
-  QUEUE node;
-  bool busy;  // prevent recursion if the dict is changed in the callback
-  bool needs_free;
-} DictWatcher;
-
-/// Bool variable values
-typedef enum {
-  kBoolVarFalse,         ///< v:false
-  kBoolVarTrue,          ///< v:true
-} BoolVarValue;
-
-/// Special variable values
-typedef enum {
-  kSpecialVarNull,   ///< v:null
-} SpecialVarValue;
-
-/// Variable lock status for typval_T.v_lock
-typedef enum {
-  VAR_UNLOCKED = 0,  ///< Not locked.
-  VAR_LOCKED = 1,    ///< User lock, can be unlocked.
-  VAR_FIXED = 2,     ///< Locked forever.
-} VarLockStatus;
-
-/// VimL variable types, for use in typval_T.v_type
-typedef enum {
-  VAR_UNKNOWN = 0,  ///< Unknown (unspecified) value.
-  VAR_NUMBER,       ///< Number, .v_number is used.
-  VAR_STRING,       ///< String, .v_string is used.
-  VAR_FUNC,         ///< Function reference, .v_string is used as function name.
-  VAR_LIST,         ///< List, .v_list is used.
-  VAR_DICT,         ///< Dictionary, .v_dict is used.
-  VAR_FLOAT,        ///< Floating-point value, .v_float is used.
-  VAR_BOOL,         ///< true, false
-  VAR_SPECIAL,      ///< Special value (null), .v_special
-                    ///< is used.
-  VAR_PARTIAL,      ///< Partial, .v_partial is used.
-  VAR_BLOB,         ///< Blob, .v_blob is used.
-} VarType;
-
-/// Structure that holds an internal variable value
-typedef struct {
-  VarType v_type;               ///< Variable type.
-  VarLockStatus v_lock;         ///< Variable lock status.
-  union typval_vval_union {
-    varnumber_T v_number;       ///< Number, for VAR_NUMBER.
-    BoolVarValue v_bool;        ///< Bool value, for VAR_BOOL
-    SpecialVarValue v_special;  ///< Special value, for VAR_SPECIAL.
-    float_T v_float;            ///< Floating-point number, for VAR_FLOAT.
-    char *v_string;             ///< String, for VAR_STRING and VAR_FUNC, can be NULL.
-    list_T *v_list;             ///< List for VAR_LIST, can be NULL.
-    dict_T *v_dict;             ///< Dictionary for VAR_DICT, can be NULL.
-    partial_T *v_partial;       ///< Closure: function with args.
-    blob_T *v_blob;             ///< Blob for VAR_BLOB, can be NULL.
-  } vval;                       ///< Actual value.
-} typval_T;
-
-/// Values for (struct dictvar_S).dv_scope
-typedef enum {
-  VAR_NO_SCOPE = 0,  ///< Not a scope dictionary.
-  VAR_SCOPE = 1,  ///< Scope dictionary which requires prefix (a:, v:, …).
-  VAR_DEF_SCOPE = 2,  ///< Scope dictionary which may be accessed without prefix
-                      ///< (l:, g:).
-} ScopeType;
-
-/// Structure to hold an item of a list
-typedef struct listitem_S listitem_T;
-
-struct listitem_S {
-  listitem_T *li_next;  ///< Next item in list.
-  listitem_T *li_prev;  ///< Previous item in list.
-  typval_T li_tv;  ///< Item value.
-};
-
-/// Structure used by those that are using an item in a list
-typedef struct listwatch_S listwatch_T;
-
-struct listwatch_S {
-  listitem_T *lw_item;  ///< Item being watched.
-  listwatch_T *lw_next;  ///< Next watcher.
-};
-
-/// Structure to hold info about a list
-/// Order of members is optimized to reduce padding.
-struct listvar_S {
-  listitem_T *lv_first;  ///< First item, NULL if none.
-  listitem_T *lv_last;  ///< Last item, NULL if none.
-  listwatch_T *lv_watch;  ///< First watcher, NULL if none.
-  listitem_T *lv_idx_item;  ///< When not NULL item at index "lv_idx".
-  list_T *lv_copylist;  ///< Copied list used by deepcopy().
-  list_T *lv_used_next;  ///< next list in used lists list.
-  list_T *lv_used_prev;  ///< Previous list in used lists list.
-  int lv_refcount;  ///< Reference count.
-  int lv_len;  ///< Number of items.
-  int lv_idx;  ///< Index of a cached item, used for optimising repeated l[idx].
-  int lv_copyID;  ///< ID used by deepcopy().
-  VarLockStatus lv_lock;  ///< Zero, VAR_LOCKED, VAR_FIXED.
-
-  LuaRef lua_table_ref;
-};
-
-// Static list with 10 items. Use tv_list_init_static10() to initialize.
-typedef struct {
-  list_T sl_list;  // must be first
-  listitem_T sl_items[10];
-} staticList10_T;
-
-#define TV_LIST_STATIC10_INIT { \
-  .sl_list = { \
-  .lv_first = NULL, \
-  .lv_last = NULL, \
-  .lv_refcount = 0, \
-  .lv_len = 0, \
-  .lv_watch = NULL, \
-  .lv_idx_item = NULL, \
-  .lv_lock = VAR_FIXED, \
-  .lv_used_next = NULL, \
-  .lv_used_prev = NULL, \
-  }, \
-}
-
-#define TV_DICTITEM_STRUCT(...) \
-  struct { \
-    typval_T di_tv;  /* Structure that holds scope dictionary itself. */ \
-    uint8_t di_flags;  /* Flags. */ \
-    char_u di_key[__VA_ARGS__];  /* Key value. */ \
-  }
-
-/// Structure to hold a scope dictionary
-///
-/// @warning Must be compatible with dictitem_T.
-///
-/// For use in find_var_in_ht to pretend that it found dictionary item when it
-/// finds scope dictionary.
-typedef TV_DICTITEM_STRUCT(1) ScopeDictDictItem;
-
-/// Structure to hold an item of a Dictionary
-///
-/// @warning Must be compatible with ScopeDictDictItem.
-///
-/// Also used for a variable.
-typedef TV_DICTITEM_STRUCT() dictitem_T;
-
-/// Flags for dictitem_T.di_flags
-typedef enum {
-  DI_FLAGS_RO = 1,  ///< Read-only value
-  DI_FLAGS_RO_SBX = 2,  ///< Value, read-only in the sandbox
-  DI_FLAGS_FIX = 4,  ///< Fixed value: cannot be :unlet or remove()d.
-  DI_FLAGS_LOCK = 8,  ///< Locked value.
-  DI_FLAGS_ALLOC = 16,  ///< Separately allocated.
-} DictItemFlags;
-
-/// Structure representing a Dictionary
-struct dictvar_S {
-  VarLockStatus dv_lock;  ///< Whole dictionary lock status.
-  ScopeType dv_scope;     ///< Non-zero (#VAR_SCOPE, #VAR_DEF_SCOPE) if
-                          ///< dictionary represents a scope (i.e. g:, l: …).
-  int dv_refcount;        ///< Reference count.
-  int dv_copyID;          ///< ID used when recursivery traversing a value.
-  hashtab_T dv_hashtab;   ///< Hashtab containing all items.
-  dict_T *dv_copydict;    ///< Copied dict used by deepcopy().
-  dict_T *dv_used_next;   ///< Next dictionary in used dictionaries list.
-  dict_T *dv_used_prev;   ///< Previous dictionary in used dictionaries list.
-  QUEUE watchers;         ///< Dictionary key watchers set by user code.
-
-  LuaRef lua_table_ref;
-};
-
-/// Structure to hold info about a Blob
-struct blobvar_S {
-  garray_T bv_ga;         ///< Growarray with the data.
-  int bv_refcount;        ///< Reference count.
-  VarLockStatus bv_lock;  ///< VAR_UNLOCKED, VAR_LOCKED, VAR_FIXED.
-};
-
-/// Type used for script ID
-typedef int scid_T;
-/// Format argument for scid_T
-#define PRIdSCID "d"
-
-// SCript ConteXt (SCTX): identifies a script line.
-// When sourcing a script "sc_lnum" is zero, "sourcing_lnum" is the current
-// line number. When executing a user function "sc_lnum" is the line where the
-// function was defined, "sourcing_lnum" is the line number inside the
-// function.  When stored with a function, mapping, option, etc. "sc_lnum" is
-// the line number in the script "sc_sid".
-typedef struct {
-  scid_T sc_sid;     // script ID
-  int sc_seq;        // sourcing sequence number
-  linenr_T sc_lnum;  // line number
-} sctx_T;
-
-/// Maximum number of function arguments
-#define MAX_FUNC_ARGS   20
-/// Short variable name length
-#define VAR_SHORT_LEN 20
-/// Number of fixed variables used for arguments
-#define FIXVAR_CNT 12
-
-/// Callback interface for C function reference>
-///     Used for managing functions that were registered with |register_cfunc|
-typedef int (*cfunc_T)(int argcount, typval_T *argvars, typval_T *rettv, void *state);  // NOLINT
-/// Callback to clear cfunc_T and any associated state.
-typedef void (*cfunc_free_T)(void *state);
-
-// Structure to hold info for a function that is currently being executed.
-typedef struct funccall_S funccall_T;
-
-struct funccall_S {
-  ufunc_T *func;  ///< Function being called.
-  int linenr;  ///< Next line to be executed.
-  int returned;  ///< ":return" used.
-  /// Fixed variables for arguments.
-  TV_DICTITEM_STRUCT(VAR_SHORT_LEN + 1) fixvar[FIXVAR_CNT];
-  dict_T l_vars;  ///< l: local function variables.
-  ScopeDictDictItem l_vars_var;  ///< Variable for l: scope.
-  dict_T l_avars;  ///< a: argument variables.
-  ScopeDictDictItem l_avars_var;  ///< Variable for a: scope.
-  list_T l_varlist;  ///< List for a:000.
-  listitem_T l_listitems[MAX_FUNC_ARGS];  ///< List items for a:000.
-  typval_T *rettv;  ///< Return value.
-  linenr_T breakpoint;  ///< Next line with breakpoint or zero.
-  int dbg_tick;  ///< Debug_tick when breakpoint was set.
-  int level;  ///< Top nesting level of executed function.
-  proftime_T prof_child;  ///< Time spent in a child.
-  funccall_T *caller;  ///< Calling function or NULL; or next funccal in
-                       ///< list pointed to by previous_funccal.
-  int fc_refcount;  ///< Number of user functions that reference this funccall.
-  int fc_copyID;  ///< CopyID used for garbage collection.
-  garray_T fc_funcs;  ///< List of ufunc_T* which keep a reference to "func".
-};
-
-/// Structure to hold info for a user function.
-struct ufunc {
-  int uf_varargs;       ///< variable nr of arguments
-  int uf_flags;
-  int uf_calls;         ///< nr of active calls
-  bool uf_cleared;       ///< func_clear() was already called
-  garray_T uf_args;          ///< arguments
-  garray_T uf_def_args;      ///< default argument expressions
-  garray_T uf_lines;         ///< function lines
-  int uf_profiling;     ///< true when func is being profiled
-  int uf_prof_initialized;
-  // Managing cfuncs
-  cfunc_T uf_cb;            ///< C function extension callback
-  cfunc_free_T uf_cb_free;       ///< C function extension free callback
-  void *uf_cb_state;      ///< State of C function extension.
-  // Profiling the function as a whole.
-  int uf_tm_count;      ///< nr of calls
-  proftime_T uf_tm_total;      ///< time spent in function + children
-  proftime_T uf_tm_self;       ///< time spent in function itself
-  proftime_T uf_tm_children;   ///< time spent in children this call
-  // Profiling the function per line.
-  int *uf_tml_count;     ///< nr of times line was executed
-  proftime_T *uf_tml_total;     ///< time spent in a line + children
-  proftime_T *uf_tml_self;      ///< time spent in a line itself
-  proftime_T uf_tml_start;     ///< start time for current line
-  proftime_T uf_tml_children;  ///< time spent in children for this line
-  proftime_T uf_tml_wait;      ///< start wait time for current line
-  int uf_tml_idx;       ///< index of line being timed; -1 if none
-  int uf_tml_execed;    ///< line being timed was executed
-  sctx_T uf_script_ctx;    ///< SCTX where function was defined,
-                           ///< used for s: variables
-  int uf_refcount;      ///< reference count, see func_name_refcount()
-  funccall_T *uf_scoped;       ///< l: local variables for closure
-  char_u *uf_name_exp;  ///< if "uf_name[]" starts with SNR the name with
-                        ///< "<SNR>" as a string, otherwise NULL
-  char_u uf_name[];  ///< Name of function (actual size equals name);
-                     ///< can start with <SNR>123_
-                     ///< (<SNR> is K_SPECIAL KS_EXTRA KE_SNR)
-};
-
-struct partial_S {
-  int pt_refcount;  ///< Reference count.
-  char_u *pt_name;  ///< Function name; when NULL use pt_func->name.
-  ufunc_T *pt_func;  ///< Function pointer; when NULL lookup function with
-                     ///< pt_name.
-  bool pt_auto;  ///< When true the partial was created by using dict.member
-                 ///< in handle_subscript().
-  int pt_argc;  ///< Number of arguments.
-  typval_T *pt_argv;  ///< Arguments in allocated array.
-  dict_T *pt_dict;  ///< Dict for "self".
-};
-
-/// Structure used for explicit stack while garbage collecting hash tables
-typedef struct ht_stack_S {
-  hashtab_T *ht;
-  struct ht_stack_S *prev;
-} ht_stack_T;
-
-/// Structure used for explicit stack while garbage collecting lists
-typedef struct list_stack_S {
-  list_T *list;
-  struct list_stack_S *prev;
-} list_stack_T;
-
-/// Structure representing one list item, used for sort array.
-typedef struct {
-  listitem_T *item;  ///< Sorted list item.
-  int idx;  ///< Sorted list item index.
-} ListSortItem;
-
-typedef int (*ListSorter)(const void *, const void *);
 
 #ifdef LOG_LIST_ACTIONS
-
-/// List actions log entry
-typedef struct {
-  uintptr_t l;  ///< List log entry belongs to.
-  uintptr_t li1;  ///< First list item log entry belongs to, if applicable.
-  uintptr_t li2;  ///< Second list item log entry belongs to, if applicable.
-  int len;  ///< List length when log entry was created.
-  const char *action;  ///< Logged action.
-} ListLogEntry;
-
-typedef struct list_log ListLog;
-
-/// List actions log
-struct list_log {
-  ListLog *next;  ///< Next chunk or NULL.
-  size_t capacity;  ///< Number of entries in current chunk.
-  size_t size;  ///< Current chunk size.
-  ListLogEntry entries[];  ///< Actual log entries.
-};
+# include "nvim/memory.h"
 
 extern ListLog *list_log_first;  ///< First list log chunk, NULL if missing
 extern ListLog *list_log_last;  ///< Last list log chunk
@@ -790,12 +394,6 @@ static inline void tv_init(typval_T *const tv)
   }
 }
 
-#define TV_INITIAL_VALUE \
-  ((typval_T) { \
-    .v_type = VAR_UNKNOWN, \
-    .v_lock = VAR_UNLOCKED, \
-  })
-
 /// Empty string
 ///
 /// Needed for hack which allows not allocating empty string and still not
@@ -894,9 +492,6 @@ static inline bool tv_get_float_chk(const typval_T *const tv,
                                     float_T *const ret_f)
   REAL_FATTR_NONNULL_ALL REAL_FATTR_WARN_UNUSED_RESULT;
 
-// FIXME circular dependency, cannot import message.h.
-bool semsg(const char *const fmt, ...);
-
 /// Get the float value
 ///
 /// Raises an error if object is not number or floating-point.
diff --git a/src/nvim/eval/typval_defs.h b/src/nvim/eval/typval_defs.h
new file mode 100644
index 0000000000..1c0a438751
--- /dev/null
+++ b/src/nvim/eval/typval_defs.h
@@ -0,0 +1,399 @@
+#ifndef NVIM_EVAL_TYPVAL_DEFS_H
+#define NVIM_EVAL_TYPVAL_DEFS_H
+
+#include <inttypes.h>
+#include <limits.h>
+
+#include "nvim/garray.h"
+#include "nvim/hashtab.h"
+#include "nvim/lib/queue.h"
+#include "nvim/pos.h"
+#include "nvim/types.h"
+
+/// Type used for VimL VAR_NUMBER values
+typedef int64_t varnumber_T;
+typedef uint64_t uvarnumber_T;
+
+/// Refcount for dict or list that should not be freed
+enum { DO_NOT_FREE_CNT = (INT_MAX / 2), };
+
+/// Additional values for tv_list_alloc() len argument
+enum ListLenSpecials {
+  /// List length is not known in advance
+  ///
+  /// To be used when there is neither a way to know how many elements will be
+  /// needed nor are any educated guesses.
+  kListLenUnknown = -1,
+  /// List length *should* be known, but is actually not
+  ///
+  /// All occurrences of this value should be eventually removed. This is for
+  /// the case when the only reason why list length is not known is that it
+  /// would be hard to code without refactoring, but refactoring is needed.
+  kListLenShouldKnow = -2,
+  /// List length may be known in advance, but it requires too much effort
+  ///
+  /// To be used when it looks impractical to determine list length.
+  kListLenMayKnow = -3,
+};
+
+/// Maximal possible value of varnumber_T variable
+#define VARNUMBER_MAX INT64_MAX
+#define UVARNUMBER_MAX UINT64_MAX
+
+/// Minimal possible value of varnumber_T variable
+#define VARNUMBER_MIN INT64_MIN
+
+/// %d printf format specifier for varnumber_T
+#define PRIdVARNUMBER PRId64
+
+typedef struct listvar_S list_T;
+typedef struct dictvar_S dict_T;
+typedef struct partial_S partial_T;
+typedef struct blobvar_S blob_T;
+
+typedef struct ufunc ufunc_T;
+
+typedef enum {
+  kCallbackNone = 0,
+  kCallbackFuncref,
+  kCallbackPartial,
+  kCallbackLua,
+} CallbackType;
+
+typedef struct {
+  union {
+    char *funcref;
+    partial_T *partial;
+    LuaRef luaref;
+  } data;
+  CallbackType type;
+} Callback;
+
+#define CALLBACK_INIT { .type = kCallbackNone }
+#define CALLBACK_NONE ((Callback)CALLBACK_INIT)
+
+/// Structure holding dictionary watcher
+typedef struct dict_watcher {
+  Callback callback;
+  char *key_pattern;
+  size_t key_pattern_len;
+  QUEUE node;
+  bool busy;  // prevent recursion if the dict is changed in the callback
+  bool needs_free;
+} DictWatcher;
+
+/// Bool variable values
+typedef enum {
+  kBoolVarFalse,         ///< v:false
+  kBoolVarTrue,          ///< v:true
+} BoolVarValue;
+
+/// Special variable values
+typedef enum {
+  kSpecialVarNull,   ///< v:null
+} SpecialVarValue;
+
+/// Variable lock status for typval_T.v_lock
+typedef enum {
+  VAR_UNLOCKED = 0,  ///< Not locked.
+  VAR_LOCKED = 1,    ///< User lock, can be unlocked.
+  VAR_FIXED = 2,     ///< Locked forever.
+} VarLockStatus;
+
+/// VimL variable types, for use in typval_T.v_type
+typedef enum {
+  VAR_UNKNOWN = 0,  ///< Unknown (unspecified) value.
+  VAR_NUMBER,       ///< Number, .v_number is used.
+  VAR_STRING,       ///< String, .v_string is used.
+  VAR_FUNC,         ///< Function reference, .v_string is used as function name.
+  VAR_LIST,         ///< List, .v_list is used.
+  VAR_DICT,         ///< Dictionary, .v_dict is used.
+  VAR_FLOAT,        ///< Floating-point value, .v_float is used.
+  VAR_BOOL,         ///< true, false
+  VAR_SPECIAL,      ///< Special value (null), .v_special is used.
+  VAR_PARTIAL,      ///< Partial, .v_partial is used.
+  VAR_BLOB,         ///< Blob, .v_blob is used.
+} VarType;
+
+/// Structure that holds an internal variable value
+typedef struct {
+  VarType v_type;               ///< Variable type.
+  VarLockStatus v_lock;         ///< Variable lock status.
+  union typval_vval_union {
+    varnumber_T v_number;       ///< Number, for VAR_NUMBER.
+    BoolVarValue v_bool;        ///< Bool value, for VAR_BOOL
+    SpecialVarValue v_special;  ///< Special value, for VAR_SPECIAL.
+    float_T v_float;            ///< Floating-point number, for VAR_FLOAT.
+    char *v_string;             ///< String, for VAR_STRING and VAR_FUNC, can be NULL.
+    list_T *v_list;             ///< List for VAR_LIST, can be NULL.
+    dict_T *v_dict;             ///< Dictionary for VAR_DICT, can be NULL.
+    partial_T *v_partial;       ///< Closure: function with args.
+    blob_T *v_blob;             ///< Blob for VAR_BLOB, can be NULL.
+  } vval;                       ///< Actual value.
+} typval_T;
+
+#define TV_INITIAL_VALUE \
+  ((typval_T) { \
+    .v_type = VAR_UNKNOWN, \
+    .v_lock = VAR_UNLOCKED, \
+  })
+
+/// Values for (struct dictvar_S).dv_scope
+typedef enum {
+  VAR_NO_SCOPE = 0,  ///< Not a scope dictionary.
+  VAR_SCOPE = 1,  ///< Scope dictionary which requires prefix (a:, v:, …).
+  VAR_DEF_SCOPE = 2,  ///< Scope dictionary which may be accessed without prefix
+                      ///< (l:, g:).
+} ScopeType;
+
+/// Structure to hold an item of a list
+typedef struct listitem_S listitem_T;
+
+struct listitem_S {
+  listitem_T *li_next;  ///< Next item in list.
+  listitem_T *li_prev;  ///< Previous item in list.
+  typval_T li_tv;  ///< Item value.
+};
+
+/// Structure used by those that are using an item in a list
+typedef struct listwatch_S listwatch_T;
+
+struct listwatch_S {
+  listitem_T *lw_item;  ///< Item being watched.
+  listwatch_T *lw_next;  ///< Next watcher.
+};
+
+/// Structure to hold info about a list
+/// Order of members is optimized to reduce padding.
+struct listvar_S {
+  listitem_T *lv_first;  ///< First item, NULL if none.
+  listitem_T *lv_last;  ///< Last item, NULL if none.
+  listwatch_T *lv_watch;  ///< First watcher, NULL if none.
+  listitem_T *lv_idx_item;  ///< When not NULL item at index "lv_idx".
+  list_T *lv_copylist;  ///< Copied list used by deepcopy().
+  list_T *lv_used_next;  ///< next list in used lists list.
+  list_T *lv_used_prev;  ///< Previous list in used lists list.
+  int lv_refcount;  ///< Reference count.
+  int lv_len;  ///< Number of items.
+  int lv_idx;  ///< Index of a cached item, used for optimising repeated l[idx].
+  int lv_copyID;  ///< ID used by deepcopy().
+  VarLockStatus lv_lock;  ///< Zero, VAR_LOCKED, VAR_FIXED.
+
+  LuaRef lua_table_ref;
+};
+
+/// Static list with 10 items. Use tv_list_init_static10() to initialize.
+typedef struct {
+  list_T sl_list;  // must be first
+  listitem_T sl_items[10];
+} staticList10_T;
+
+#define TV_LIST_STATIC10_INIT { \
+  .sl_list = { \
+  .lv_first = NULL, \
+  .lv_last = NULL, \
+  .lv_refcount = 0, \
+  .lv_len = 0, \
+  .lv_watch = NULL, \
+  .lv_idx_item = NULL, \
+  .lv_lock = VAR_FIXED, \
+  .lv_used_next = NULL, \
+  .lv_used_prev = NULL, \
+  }, \
+}
+
+#define TV_DICTITEM_STRUCT(...) \
+  struct { \
+    typval_T di_tv;  /* Structure that holds scope dictionary itself. */ \
+    uint8_t di_flags;  /* Flags. */ \
+    char_u di_key[__VA_ARGS__];  /* Key value. */ \
+  }
+
+/// Structure to hold a scope dictionary
+///
+/// @warning Must be compatible with dictitem_T.
+///
+/// For use in find_var_in_ht to pretend that it found dictionary item when it
+/// finds scope dictionary.
+typedef TV_DICTITEM_STRUCT(1) ScopeDictDictItem;
+
+/// Structure to hold an item of a Dictionary
+///
+/// @warning Must be compatible with ScopeDictDictItem.
+///
+/// Also used for a variable.
+typedef TV_DICTITEM_STRUCT() dictitem_T;
+
+/// Flags for dictitem_T.di_flags
+typedef enum {
+  DI_FLAGS_RO = 1,  ///< Read-only value
+  DI_FLAGS_RO_SBX = 2,  ///< Value, read-only in the sandbox
+  DI_FLAGS_FIX = 4,  ///< Fixed value: cannot be :unlet or remove()d.
+  DI_FLAGS_LOCK = 8,  ///< Locked value.
+  DI_FLAGS_ALLOC = 16,  ///< Separately allocated.
+} DictItemFlags;
+
+/// Structure representing a Dictionary
+struct dictvar_S {
+  VarLockStatus dv_lock;  ///< Whole dictionary lock status.
+  ScopeType dv_scope;     ///< Non-zero (#VAR_SCOPE, #VAR_DEF_SCOPE) if
+                          ///< dictionary represents a scope (i.e. g:, l: …).
+  int dv_refcount;        ///< Reference count.
+  int dv_copyID;          ///< ID used when recursivery traversing a value.
+  hashtab_T dv_hashtab;   ///< Hashtab containing all items.
+  dict_T *dv_copydict;    ///< Copied dict used by deepcopy().
+  dict_T *dv_used_next;   ///< Next dictionary in used dictionaries list.
+  dict_T *dv_used_prev;   ///< Previous dictionary in used dictionaries list.
+  QUEUE watchers;         ///< Dictionary key watchers set by user code.
+
+  LuaRef lua_table_ref;
+};
+
+/// Structure to hold info about a Blob
+struct blobvar_S {
+  garray_T bv_ga;         ///< Growarray with the data.
+  int bv_refcount;        ///< Reference count.
+  VarLockStatus bv_lock;  ///< VAR_UNLOCKED, VAR_LOCKED, VAR_FIXED.
+};
+
+/// Type used for script ID
+typedef int scid_T;
+/// Format argument for scid_T
+#define PRIdSCID "d"
+
+/// SCript ConteXt (SCTX): identifies a script line.
+/// When sourcing a script "sc_lnum" is zero, "sourcing_lnum" is the current
+/// line number. When executing a user function "sc_lnum" is the line where the
+/// function was defined, "sourcing_lnum" is the line number inside the
+/// function.  When stored with a function, mapping, option, etc. "sc_lnum" is
+/// the line number in the script "sc_sid".
+typedef struct {
+  scid_T sc_sid;     ///< script ID
+  int sc_seq;        ///< sourcing sequence number
+  linenr_T sc_lnum;  ///< line number
+} sctx_T;
+
+/// Maximum number of function arguments
+enum { MAX_FUNC_ARGS = 20, };
+/// Short variable name length
+enum { VAR_SHORT_LEN = 20, };
+/// Number of fixed variables used for arguments
+enum { FIXVAR_CNT = 12, };
+
+/// Structure to hold info for a function that is currently being executed.
+typedef struct funccall_S funccall_T;
+
+struct funccall_S {
+  ufunc_T *func;  ///< Function being called.
+  int linenr;  ///< Next line to be executed.
+  int returned;  ///< ":return" used.
+  /// Fixed variables for arguments.
+  TV_DICTITEM_STRUCT(VAR_SHORT_LEN + 1) fixvar[FIXVAR_CNT];
+  dict_T l_vars;  ///< l: local function variables.
+  ScopeDictDictItem l_vars_var;  ///< Variable for l: scope.
+  dict_T l_avars;  ///< a: argument variables.
+  ScopeDictDictItem l_avars_var;  ///< Variable for a: scope.
+  list_T l_varlist;  ///< List for a:000.
+  listitem_T l_listitems[MAX_FUNC_ARGS];  ///< List items for a:000.
+  typval_T *rettv;  ///< Return value.
+  linenr_T breakpoint;  ///< Next line with breakpoint or zero.
+  int dbg_tick;  ///< debug_tick when breakpoint was set.
+  int level;  ///< Top nesting level of executed function.
+  proftime_T prof_child;  ///< Time spent in a child.
+  funccall_T *caller;  ///< Calling function or NULL; or next funccal in
+                       ///< list pointed to by previous_funccal.
+  int fc_refcount;  ///< Number of user functions that reference this funccall.
+  int fc_copyID;  ///< CopyID used for garbage collection.
+  garray_T fc_funcs;  ///< List of ufunc_T* which keep a reference to "func".
+};
+
+/// Structure to hold info for a user function.
+struct ufunc {
+  int uf_varargs;       ///< variable nr of arguments
+  int uf_flags;
+  int uf_calls;         ///< nr of active calls
+  bool uf_cleared;       ///< func_clear() was already called
+  garray_T uf_args;          ///< arguments
+  garray_T uf_def_args;      ///< default argument expressions
+  garray_T uf_lines;         ///< function lines
+  int uf_profiling;     ///< true when func is being profiled
+  int uf_prof_initialized;
+  LuaRef uf_luaref;      ///< lua callback, used if (uf_flags & FC_LUAREF)
+  // Profiling the function as a whole.
+  int uf_tm_count;      ///< nr of calls
+  proftime_T uf_tm_total;      ///< time spent in function + children
+  proftime_T uf_tm_self;       ///< time spent in function itself
+  proftime_T uf_tm_children;   ///< time spent in children this call
+  // Profiling the function per line.
+  int *uf_tml_count;     ///< nr of times line was executed
+  proftime_T *uf_tml_total;     ///< time spent in a line + children
+  proftime_T *uf_tml_self;      ///< time spent in a line itself
+  proftime_T uf_tml_start;     ///< start time for current line
+  proftime_T uf_tml_children;  ///< time spent in children for this line
+  proftime_T uf_tml_wait;      ///< start wait time for current line
+  int uf_tml_idx;       ///< index of line being timed; -1 if none
+  int uf_tml_execed;    ///< line being timed was executed
+  sctx_T uf_script_ctx;    ///< SCTX where function was defined,
+                           ///< used for s: variables
+  int uf_refcount;      ///< reference count, see func_name_refcount()
+  funccall_T *uf_scoped;       ///< l: local variables for closure
+  char_u *uf_name_exp;  ///< if "uf_name[]" starts with SNR the name with
+                        ///< "<SNR>" as a string, otherwise NULL
+  char_u uf_name[];  ///< Name of function (actual size equals name);
+                     ///< can start with <SNR>123_
+                     ///< (<SNR> is K_SPECIAL KS_EXTRA KE_SNR)
+};
+
+struct partial_S {
+  int pt_refcount;    ///< Reference count.
+  char *pt_name;      ///< Function name; when NULL use pt_func->name.
+  ufunc_T *pt_func;   ///< Function pointer; when NULL lookup function with pt_name.
+  bool pt_auto;       ///< When true the partial was created by using dict.member
+                      ///< in handle_subscript().
+  int pt_argc;        ///< Number of arguments.
+  typval_T *pt_argv;  ///< Arguments in allocated array.
+  dict_T *pt_dict;    ///< Dict for "self".
+};
+
+/// Structure used for explicit stack while garbage collecting hash tables
+typedef struct ht_stack_S {
+  hashtab_T *ht;
+  struct ht_stack_S *prev;
+} ht_stack_T;
+
+/// Structure used for explicit stack while garbage collecting lists
+typedef struct list_stack_S {
+  list_T *list;
+  struct list_stack_S *prev;
+} list_stack_T;
+
+/// Structure representing one list item, used for sort array.
+typedef struct {
+  listitem_T *item;  ///< Sorted list item.
+  int idx;  ///< Sorted list item index.
+} ListSortItem;
+
+typedef int (*ListSorter)(const void *, const void *);
+
+#ifdef LOG_LIST_ACTIONS
+/// List actions log entry
+typedef struct {
+  uintptr_t l;  ///< List log entry belongs to.
+  uintptr_t li1;  ///< First list item log entry belongs to, if applicable.
+  uintptr_t li2;  ///< Second list item log entry belongs to, if applicable.
+  int len;  ///< List length when log entry was created.
+  const char *action;  ///< Logged action.
+} ListLogEntry;
+
+typedef struct list_log ListLog;
+
+/// List actions log
+struct list_log {
+  ListLog *next;  ///< Next chunk or NULL.
+  size_t capacity;  ///< Number of entries in current chunk.
+  size_t size;  ///< Current chunk size.
+  ListLogEntry entries[];  ///< Actual log entries.
+};
+#endif
+
+#endif  // NVIM_EVAL_TYPVAL_DEFS_H
diff --git a/src/nvim/eval/typval_encode.c.h b/src/nvim/eval/typval_encode.c.h
index 73b36b8611..ff4f92e40b 100644
--- a/src/nvim/eval/typval_encode.c.h
+++ b/src/nvim/eval/typval_encode.c.h
@@ -250,7 +250,7 @@
 #include "nvim/eval/typval.h"
 #include "nvim/eval/typval_encode.h"
 #include "nvim/func_attr.h"
-#include "nvim/lib/kvec.h"
+#include "klib/kvec.h"
 
 // -V::1063
 
diff --git a/src/nvim/eval/typval_encode.h b/src/nvim/eval/typval_encode.h
index ed70ba87ec..33e19c531c 100644
--- a/src/nvim/eval/typval_encode.h
+++ b/src/nvim/eval/typval_encode.h
@@ -10,9 +10,9 @@
 #include <stddef.h>
 #include <string.h>
 
+#include "klib/kvec.h"
 #include "nvim/eval/typval.h"
 #include "nvim/func_attr.h"
-#include "nvim/lib/kvec.h"
 
 /// Type of the stack entry
 typedef enum {
diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 8cb7a075cb..b0a56c4440 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -28,20 +28,6 @@
 #include "nvim/ui.h"
 #include "nvim/vim.h"
 
-// flags used in uf_flags
-#define FC_ABORT    0x01          // abort function on error
-#define FC_RANGE    0x02          // function accepts range
-#define FC_DICT     0x04          // Dict function, uses "self"
-#define FC_CLOSURE  0x08          // closure, uses outer scope variables
-#define FC_DELETED  0x10          // :delfunction used while uf_refcount > 0
-#define FC_REMOVED  0x20          // function redefined while uf_refcount > 0
-#define FC_SANDBOX  0x40          // function defined in the sandbox
-#define FC_DEAD     0x80          // function kept only for reference to dfunc
-#define FC_EXPORT   0x100         // "export def Func()"
-#define FC_NOARGS   0x200         // no a: variables in lambda
-#define FC_VIM9     0x400         // defined in vim9 script file
-#define FC_CFUNC    0x800         // C function extension
-
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "eval/userfunc.c.generated.h"
 #endif
@@ -125,7 +111,7 @@ static int get_function_args(char **argp, char_u endchar, garray_T *newargs, int
 
         // Check for duplicate argument name.
         for (i = 0; i < newargs->ga_len; i++) {
-          if (STRCMP(((char **)(newargs->ga_data))[i], arg) == 0) {
+          if (strcmp(((char **)(newargs->ga_data))[i], arg) == 0) {
             semsg(_("E853: Duplicate argument name: %s"), arg);
             xfree(arg);
             goto err_ret;
@@ -142,18 +128,18 @@ static int get_function_args(char **argp, char_u endchar, garray_T *newargs, int
         any_default = true;
         p = skipwhite(p) + 1;
         p = skipwhite(p);
-        char_u *expr = (char_u *)p;
+        char *expr = p;
         if (eval1(&p, &rettv, false) != FAIL) {
           ga_grow(default_args, 1);
 
           // trim trailing whitespace
-          while (p > (char *)expr && ascii_iswhite(p[-1])) {
+          while (p > expr && ascii_iswhite(p[-1])) {
             p--;
           }
           c = (char_u)(*p);
           *p = NUL;
-          expr = vim_strsave(expr);
-          ((char **)(default_args->ga_data))[default_args->ga_len] = (char *)expr;
+          expr = xstrdup(expr);
+          ((char **)(default_args->ga_data))[default_args->ga_len] = expr;
           default_args->ga_len++;
           *p = (char)c;
         } else {
@@ -378,7 +364,7 @@ char_u *deref_func_name(const char *name, int *lenp, partial_T **const partialp,
       *lenp = 0;
       return (char_u *)"";
     }
-    *lenp = (int)STRLEN(v->di_tv.vval.v_string);
+    *lenp = (int)strlen(v->di_tv.vval.v_string);
     return (char_u *)v->di_tv.vval.v_string;
   }
 
@@ -409,7 +395,7 @@ void emsg_funcname(char *ermsg, const char_u *name)
   char_u *p;
 
   if (*name == K_SPECIAL) {
-    p = concat_str((char_u *)"<SNR>", name + 3);
+    p = (char_u *)concat_str("<SNR>", (char *)name + 3);
   } else {
     p = (char_u *)name;
   }
@@ -439,12 +425,12 @@ int get_func_tv(const char_u *name, int len, typval_T *rettv, char **arg, funcex
   // Get the arguments.
   argp = *arg;
   while (argcount < MAX_FUNC_ARGS
-         - (funcexe->partial == NULL ? 0 : funcexe->partial->pt_argc)) {
+         - (funcexe->fe_partial == NULL ? 0 : funcexe->fe_partial->pt_argc)) {
     argp = skipwhite(argp + 1);             // skip the '(' or ','
     if (*argp == ')' || *argp == ',' || *argp == NUL) {
       break;
     }
-    if (eval1(&argp, &argvars[argcount], funcexe->evaluate) == FAIL) {
+    if (eval1(&argp, &argvars[argcount], funcexe->fe_evaluate) == FAIL) {
       ret = FAIL;
       break;
     }
@@ -525,39 +511,38 @@ static inline bool eval_fname_sid(const char *const name)
 ///
 /// @return transformed name: either `fname_buf` or a pointer to an allocated
 ///         memory.
-static char_u *fname_trans_sid(const char_u *const name, char_u *const fname_buf,
-                               char_u **const tofree, int *const error)
+static char *fname_trans_sid(const char *const name, char *const fname_buf, char **const tofree,
+                             int *const error)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  char_u *fname;
-  const int llen = eval_fname_script((const char *)name);
-  if (llen > 0) {
-    fname_buf[0] = K_SPECIAL;
-    fname_buf[1] = KS_EXTRA;
-    fname_buf[2] = KE_SNR;
-    int i = 3;
-    if (eval_fname_sid((const char *)name)) {  // "<SID>" or "s:"
-      if (current_sctx.sc_sid <= 0) {
-        *error = ERROR_SCRIPT;
-      } else {
-        snprintf((char *)fname_buf + i, (size_t)(FLEN_FIXED + 1 - i), "%" PRId64 "_",
-                 (int64_t)current_sctx.sc_sid);
-        i = (int)STRLEN(fname_buf);
-      }
-    }
-    if ((size_t)i + STRLEN(name + llen) < FLEN_FIXED) {
-      STRCPY(fname_buf + i, name + llen);
-      fname = fname_buf;
+  const int llen = eval_fname_script(name);
+  if (llen == 0) {
+    return (char *)name;  // no prefix
+  }
+
+  fname_buf[0] = (char)K_SPECIAL;
+  fname_buf[1] = (char)KS_EXTRA;
+  fname_buf[2] = KE_SNR;
+  int i = 3;
+  if (eval_fname_sid(name)) {  // "<SID>" or "s:"
+    if (current_sctx.sc_sid <= 0) {
+      *error = FCERR_SCRIPT;
     } else {
-      fname = xmalloc((size_t)i + STRLEN(name + llen) + 1);
-      *tofree = fname;
-      memmove(fname, fname_buf, (size_t)i);
-      STRCPY(fname + i, name + llen);
+      snprintf(fname_buf + i, (size_t)(FLEN_FIXED + 1 - i), "%" PRId64 "_",
+               (int64_t)current_sctx.sc_sid);
+      i = (int)strlen(fname_buf);
     }
+  }
+  char *fname;
+  if ((size_t)i + strlen(name + llen) < FLEN_FIXED) {
+    STRCPY(fname_buf + i, name + llen);
+    fname = fname_buf;
   } else {
-    fname = (char_u *)name;
+    fname = xmalloc((size_t)i + strlen(name + llen) + 1);
+    *tofree = fname;
+    memmove(fname, fname_buf, (size_t)i);
+    STRCPY(fname + i, name + llen);
   }
-
   return fname;
 }
 
@@ -758,9 +743,9 @@ static void func_clear_items(ufunc_T *fp)
   ga_clear_strings(&(fp->uf_lines));
   XFREE_CLEAR(fp->uf_name_exp);
 
-  if (fp->uf_cb_free != NULL) {
-    fp->uf_cb_free(fp->uf_cb_state);
-    fp->uf_cb_free = NULL;
+  if (fp->uf_flags & FC_LUAREF) {
+    api_free_luaref(fp->uf_luaref);
+    fp->uf_luaref = LUA_NOREF;
   }
 
   XFREE_CLEAR(fp->uf_tml_count);
@@ -863,7 +848,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
   fc->rettv = rettv;
   fc->level = ex_nesting_level;
   // Check if this function has a breakpoint.
-  fc->breakpoint = dbg_find_breakpoint(false, fp->uf_name, (linenr_T)0);
+  fc->breakpoint = dbg_find_breakpoint(false, (char *)fp->uf_name, (linenr_T)0);
   fc->dbg_tick = debug_tick;
 
   // Set up fields for closure.
@@ -970,11 +955,11 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
       snprintf((char *)numbuf, sizeof(numbuf), "%d", ai + 1);
       name = (char *)numbuf;
     }
-    if (fixvar_idx < FIXVAR_CNT && STRLEN(name) <= VAR_SHORT_LEN) {
+    if (fixvar_idx < FIXVAR_CNT && strlen(name) <= VAR_SHORT_LEN) {
       v = (dictitem_T *)&fc->fixvar[fixvar_idx++];
       v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX;
     } else {
-      v = xmalloc(sizeof(dictitem_T) + STRLEN(name));
+      v = xmalloc(sizeof(dictitem_T) + strlen(name));
       v->di_flags = DI_FLAGS_RO | DI_FLAGS_FIX | DI_FLAGS_ALLOC;
     }
     STRCPY(v->di_key, name);
@@ -1058,7 +1043,7 @@ void call_user_func(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rett
 
   bool func_not_yet_profiling_but_should =
     do_profiling_yes
-    && !fp->uf_profiling && has_profiling(false, fp->uf_name, NULL);
+    && !fp->uf_profiling && has_profiling(false, (char *)fp->uf_name, NULL);
 
   if (func_not_yet_profiling_but_should) {
     started_profiling = true;
@@ -1213,6 +1198,34 @@ static bool func_name_refcount(char_u *name)
   return isdigit(*name) || *name == '<';
 }
 
+/// Call a user function after checking the arguments.
+static int call_user_func_check(ufunc_T *fp, int argcount, typval_T *argvars, typval_T *rettv,
+                                funcexe_T *funcexe, dict_T *selfdict)
+  FUNC_ATTR_NONNULL_ARG(1, 3, 4, 5)
+{
+  if (fp->uf_flags & FC_LUAREF) {
+    return typval_exec_lua_callable(fp->uf_luaref, argcount, argvars, rettv);
+  }
+
+  if ((fp->uf_flags & FC_RANGE) && funcexe->fe_doesrange != NULL) {
+    *funcexe->fe_doesrange = true;
+  }
+  int error;
+  if (argcount < fp->uf_args.ga_len - fp->uf_def_args.ga_len) {
+    error = FCERR_TOOFEW;
+  } else if (!fp->uf_varargs && argcount > fp->uf_args.ga_len) {
+    error = FCERR_TOOMANY;
+  } else if ((fp->uf_flags & FC_DICT) && selfdict == NULL) {
+    error = FCERR_DICT;
+  } else {
+    // Call the user function.
+    call_user_func(fp, argcount, argvars, rettv, funcexe->fe_firstline, funcexe->fe_lastline,
+                   (fp->uf_flags & FC_DICT) ? selfdict : NULL);
+    error = FCERR_NONE;
+  }
+  return error;
+}
+
 static funccal_entry_T *funccal_stack = NULL;
 
 /// Save the current function call pointer, and set it to NULL.
@@ -1353,11 +1366,11 @@ int func_call(char_u *name, typval_T *args, partial_T *partial, dict_T *selfdict
   });
 
   funcexe_T funcexe = FUNCEXE_INIT;
-  funcexe.firstline = curwin->w_cursor.lnum;
-  funcexe.lastline = curwin->w_cursor.lnum;
-  funcexe.evaluate = true;
-  funcexe.partial = partial;
-  funcexe.selfdict = selfdict;
+  funcexe.fe_firstline = curwin->w_cursor.lnum;
+  funcexe.fe_lastline = curwin->w_cursor.lnum;
+  funcexe.fe_evaluate = true;
+  funcexe.fe_partial = partial;
+  funcexe.fe_selfdict = selfdict;
   r = call_func((char *)name, -1, rettv, argc, argv, &funcexe);
 
 func_call_skip_call:
@@ -1375,27 +1388,27 @@ static void user_func_error(int error, const char_u *name)
   FUNC_ATTR_NONNULL_ALL
 {
   switch (error) {
-  case ERROR_UNKNOWN:
+  case FCERR_UNKNOWN:
     emsg_funcname(N_("E117: Unknown function: %s"), name);
     break;
-  case ERROR_NOTMETHOD:
+  case FCERR_NOTMETHOD:
     emsg_funcname(N_("E276: Cannot use function as a method: %s"), name);
     break;
-  case ERROR_DELETED:
+  case FCERR_DELETED:
     emsg_funcname(N_("E933: Function was deleted: %s"), name);
     break;
-  case ERROR_TOOMANY:
+  case FCERR_TOOMANY:
     emsg_funcname(_(e_toomanyarg), name);
     break;
-  case ERROR_TOOFEW:
+  case FCERR_TOOFEW:
     emsg_funcname(N_("E119: Not enough arguments for function: %s"),
                   name);
     break;
-  case ERROR_SCRIPT:
+  case FCERR_SCRIPT:
     emsg_funcname(N_("E120: Using <SID> not in a script context: %s"),
                   name);
     break;
-  case ERROR_DICT:
+  case FCERR_DICT:
     emsg_funcname(N_("E725: Calling dict function without Dictionary: %s"),
                   name);
     break;
@@ -1435,27 +1448,27 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
   FUNC_ATTR_NONNULL_ARG(1, 3, 5, 6)
 {
   int ret = FAIL;
-  int error = ERROR_NONE;
+  int error = FCERR_NONE;
   ufunc_T *fp = NULL;
-  char_u fname_buf[FLEN_FIXED + 1];
-  char_u *tofree = NULL;
-  char_u *fname = NULL;
-  char_u *name = NULL;
+  char fname_buf[FLEN_FIXED + 1];
+  char *tofree = NULL;
+  char *fname = NULL;
+  char *name = NULL;
   int argcount = argcount_in;
   typval_T *argvars = argvars_in;
-  dict_T *selfdict = funcexe->selfdict;
+  dict_T *selfdict = funcexe->fe_selfdict;
   typval_T argv[MAX_FUNC_ARGS + 1];  // used when "partial" or
-                                     // "funcexe->basetv" is not NULL
+                                     // "funcexe->fe_basetv" is not NULL
   int argv_clear = 0;
   int argv_base = 0;
-  partial_T *partial = funcexe->partial;
+  partial_T *partial = funcexe->fe_partial;
 
   // Initialize rettv so that it is safe for caller to invoke clear_tv(rettv)
   // even when call_func() returns FAIL.
   rettv->v_type = VAR_UNKNOWN;
 
   if (len <= 0) {
-    len = (int)STRLEN(funcname);
+    len = (int)strlen(funcname);
   }
   if (partial != NULL) {
     fp = partial->pt_func;
@@ -1463,12 +1476,12 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
   if (fp == NULL) {
     // Make a copy of the name, if it comes from a funcref variable it could
     // be changed or deleted in the called function.
-    name = vim_strnsave((char_u *)funcname, (size_t)len);
-    fname = fname_trans_sid(name, fname_buf, &tofree, &error);
+    name = xstrnsave(funcname, (size_t)len);
+    fname = fname_trans_sid(name, (char *)fname_buf, &tofree, &error);
   }
 
-  if (funcexe->doesrange != NULL) {
-    *funcexe->doesrange = false;
+  if (funcexe->fe_doesrange != NULL) {
+    *funcexe->fe_doesrange = false;
   }
 
   if (partial != NULL) {
@@ -1478,10 +1491,10 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
     if (partial->pt_dict != NULL && (selfdict == NULL || !partial->pt_auto)) {
       selfdict = partial->pt_dict;
     }
-    if (error == ERROR_NONE && partial->pt_argc > 0) {
+    if (error == FCERR_NONE && partial->pt_argc > 0) {
       for (argv_clear = 0; argv_clear < partial->pt_argc; argv_clear++) {
         if (argv_clear + argcount_in >= MAX_FUNC_ARGS) {
-          error = ERROR_TOOMANY;
+          error = FCERR_TOOMANY;
           goto theend;
         }
         tv_copy(&partial->pt_argv[argv_clear], &argv[argv_clear]);
@@ -1494,8 +1507,8 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
     }
   }
 
-  if (error == ERROR_NONE && funcexe->evaluate) {
-    char_u *rfname = fname;
+  if (error == FCERR_NONE && funcexe->fe_evaluate) {
+    char *rfname = fname;
 
     // Ignore "g:" before a function name.
     if (fp == NULL && fname[0] == 'g' && fname[1] == ':') {
@@ -1504,12 +1517,12 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
 
     rettv->v_type = VAR_NUMBER;         // default rettv is number zero
     rettv->vval.v_number = 0;
-    error = ERROR_UNKNOWN;
+    error = FCERR_UNKNOWN;
 
     if (is_luafunc(partial)) {
       if (len > 0) {
-        error = ERROR_NONE;
-        argv_add_base(funcexe->basetv, &argvars, &argcount, argv, &argv_base);
+        error = FCERR_NONE;
+        argv_add_base(funcexe->fe_basetv, &argvars, &argcount, argv, &argv_base);
         nlua_typval_call(funcname, (size_t)len, argvars, argcount, rettv);
       } else {
         // v:lua was called directly; show its name in the emsg
@@ -1519,76 +1532,55 @@ int call_func(const char *funcname, int len, typval_T *rettv, int argcount_in, t
     } else if (fp != NULL || !builtin_function((const char *)rfname, -1)) {
       // User defined function.
       if (fp == NULL) {
-        fp = find_func(rfname);
+        fp = find_func((char_u *)rfname);
       }
 
       // Trigger FuncUndefined event, may load the function.
       if (fp == NULL
-          && apply_autocmds(EVENT_FUNCUNDEFINED, (char *)rfname, (char *)rfname, true, NULL)
+          && apply_autocmds(EVENT_FUNCUNDEFINED, rfname, rfname, true, NULL)
           && !aborting()) {
         // executed an autocommand, search for the function again
-        fp = find_func(rfname);
+        fp = find_func((char_u *)rfname);
       }
       // Try loading a package.
-      if (fp == NULL && script_autoload((const char *)rfname, STRLEN(rfname),
+      if (fp == NULL && script_autoload((const char *)rfname, strlen(rfname),
                                         true) && !aborting()) {
         // Loaded a package, search for the function again.
-        fp = find_func(rfname);
+        fp = find_func((char_u *)rfname);
       }
 
       if (fp != NULL && (fp->uf_flags & FC_DELETED)) {
-        error = ERROR_DELETED;
-      } else if (fp != NULL && (fp->uf_flags & FC_CFUNC)) {
-        cfunc_T cb = fp->uf_cb;
-        error = (*cb)(argcount, argvars, rettv, fp->uf_cb_state);
+        error = FCERR_DELETED;
       } else if (fp != NULL) {
-        if (funcexe->argv_func != NULL) {
+        if (funcexe->fe_argv_func != NULL) {
           // postponed filling in the arguments, do it now
-          argcount = funcexe->argv_func(argcount, argvars, argv_clear,
-                                        fp->uf_args.ga_len);
+          argcount = funcexe->fe_argv_func(argcount, argvars, argv_clear, fp);
         }
 
-        argv_add_base(funcexe->basetv, &argvars, &argcount, argv, &argv_base);
+        argv_add_base(funcexe->fe_basetv, &argvars, &argcount, argv, &argv_base);
 
-        if (fp->uf_flags & FC_RANGE && funcexe->doesrange != NULL) {
-          *funcexe->doesrange = true;
-        }
-        if (argcount < fp->uf_args.ga_len - fp->uf_def_args.ga_len) {
-          error = ERROR_TOOFEW;
-        } else if (!fp->uf_varargs && argcount > fp->uf_args.ga_len) {
-          error = ERROR_TOOMANY;
-        } else if ((fp->uf_flags & FC_DICT) && selfdict == NULL) {
-          error = ERROR_DICT;
-        } else {
-          // Call the user function.
-          call_user_func(fp, argcount, argvars, rettv, funcexe->firstline,
-                         funcexe->lastline,
-                         (fp->uf_flags & FC_DICT) ? selfdict : NULL);
-          error = ERROR_NONE;
-        }
+        error = call_user_func_check(fp, argcount, argvars, rettv, funcexe, selfdict);
       }
-    } else if (funcexe->basetv != NULL) {
+    } else if (funcexe->fe_basetv != NULL) {
       // expr->method(): Find the method name in the table, call its
       // implementation with the base as one of the arguments.
-      error = call_internal_method(fname, argcount, argvars, rettv,
-                                   funcexe->basetv);
+      error = call_internal_method((char_u *)fname, argcount, argvars, rettv,
+                                   funcexe->fe_basetv);
     } else {
       // Find the function name in the table, call its implementation.
-      error = call_internal_func(fname, argcount, argvars, rettv);
-    }
-    /*
-     * The function call (or "FuncUndefined" autocommand sequence) might
-     * have been aborted by an error, an interrupt, or an explicitly thrown
-     * exception that has not been caught so far.  This situation can be
-     * tested for by calling aborting().  For an error in an internal
-     * function or for the "E132" error in call_user_func(), however, the
-     * throw point at which the "force_abort" flag (temporarily reset by
-     * emsg()) is normally updated has not been reached yet. We need to
-     * update that flag first to make aborting() reliable.
-     */
+      error = call_internal_func((char_u *)fname, argcount, argvars, rettv);
+    }
+    // The function call (or "FuncUndefined" autocommand sequence) might
+    // have been aborted by an error, an interrupt, or an explicitly thrown
+    // exception that has not been caught so far.  This situation can be
+    // tested for by calling aborting().  For an error in an internal
+    // function or for the "E132" error in call_user_func(), however, the
+    // throw point at which the "force_abort" flag (temporarily reset by
+    // emsg()) is normally updated has not been reached yet. We need to
+    // update that flag first to make aborting() reliable.
     update_force_abort();
   }
-  if (error == ERROR_NONE) {
+  if (error == FCERR_NONE) {
     ret = OK;
   }
 
@@ -1596,7 +1588,7 @@ theend:
   // Report an error unless the argument evaluation or function call has been
   // cancelled due to an aborting error, an interrupt, or an exception.
   if (!aborting()) {
-    user_func_error(error, (name != NULL) ? name : (char_u *)funcname);
+    user_func_error(error, (name != NULL) ? (char_u *)name : (char_u *)funcname);
   }
 
   // clear the copies made from the partial
@@ -1682,7 +1674,7 @@ static void list_func_head(ufunc_T *fp, int indent, bool force)
 char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, partial_T **partial)
   FUNC_ATTR_NONNULL_ARG(1)
 {
-  char_u *name = NULL;
+  char *name = NULL;
   const char_u *start;
   const char_u *end;
   int lead;
@@ -1720,11 +1712,9 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
     goto theend;
   }
   if (end == NULL || (lv.ll_tv != NULL && (lead > 2 || lv.ll_range))) {
-    /*
-     * Report an invalid expression in braces, unless the expression
-     * evaluation has been cancelled due to an aborting error, an
-     * interrupt, or an exception.
-     */
+    // Report an invalid expression in braces, unless the expression
+    // evaluation has been cancelled due to an aborting error, an
+    // interrupt, or an exception.
     if (!aborting()) {
       if (end != NULL) {
         semsg(_(e_invarg2), start);
@@ -1743,7 +1733,7 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
       fdp->fd_di = lv.ll_di;
     }
     if (lv.ll_tv->v_type == VAR_FUNC && lv.ll_tv->vval.v_string != NULL) {
-      name = vim_strsave((char_u *)lv.ll_tv->vval.v_string);
+      name = xstrdup(lv.ll_tv->vval.v_string);
       *pp = (char *)end;
     } else if (lv.ll_tv->v_type == VAR_PARTIAL
                && lv.ll_tv->vval.v_partial != NULL) {
@@ -1757,7 +1747,7 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
         memcpy(name, end + 1, (size_t)len);
         *pp = (char *)end + 1 + len;
       } else {
-        name = vim_strsave((char_u *)partial_name(lv.ll_tv->vval.v_partial));
+        name = xstrdup(partial_name(lv.ll_tv->vval.v_partial));
         *pp = (char *)end;
       }
       if (partial != NULL) {
@@ -1785,28 +1775,28 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
   // Check if the name is a Funcref.  If so, use the value.
   if (lv.ll_exp_name != NULL) {
     len = (int)strlen(lv.ll_exp_name);
-    name = deref_func_name(lv.ll_exp_name, &len, partial,
-                           flags & TFN_NO_AUTOLOAD);
+    name = (char *)deref_func_name(lv.ll_exp_name, &len, partial,
+                                   flags & TFN_NO_AUTOLOAD);
     if ((const char *)name == lv.ll_exp_name) {
       name = NULL;
     }
   } else if (!(flags & TFN_NO_DEREF)) {
     len = (int)(end - (char_u *)(*pp));
-    name = deref_func_name((const char *)(*pp), &len, partial,
-                           flags & TFN_NO_AUTOLOAD);
-    if (name == (char_u *)(*pp)) {
+    name = (char *)deref_func_name((const char *)(*pp), &len, partial,
+                                   flags & TFN_NO_AUTOLOAD);
+    if (name == *pp) {
       name = NULL;
     }
   }
   if (name != NULL) {
-    name = vim_strsave(name);
+    name = xstrdup(name);
     *pp = (char *)end;
     if (STRNCMP(name, "<SNR>", 5) == 0) {
       // Change "<SNR>" to the byte sequence.
-      name[0] = K_SPECIAL;
-      name[1] = KS_EXTRA;
+      name[0] = (char)K_SPECIAL;
+      name[1] = (char)KS_EXTRA;
       name[2] = KE_SNR;
-      memmove(name + 3, name + 5, strlen((char *)name + 5) + 1);
+      memmove(name + 3, name + 5, strlen(name + 5) + 1);
     }
     goto theend;
   }
@@ -1869,8 +1859,8 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
 
   name = xmalloc((size_t)len + (size_t)lead + 1);
   if (!skip && lead > 0) {
-    name[0] = K_SPECIAL;
-    name[1] = KS_EXTRA;
+    name[0] = (char)K_SPECIAL;
+    name[1] = (char)KS_EXTRA;
     name[2] = KE_SNR;
     if (sid_buf_len > 0) {  // If it's "<SID>"
       memcpy(name + 3, sid_buf, sid_buf_len);
@@ -1882,7 +1872,7 @@ char_u *trans_function_name(char **pp, bool skip, int flags, funcdict_T *fdp, pa
 
 theend:
   clear_lval(&lv);
-  return name;
+  return (char_u *)name;
 }
 
 #define MAX_FUNC_NESTING 50
@@ -1890,15 +1880,15 @@ theend:
 /// ":function"
 void ex_function(exarg_T *eap)
 {
-  char_u *theline;
-  char_u *line_to_free = NULL;
-  char_u c;
+  char *theline;
+  char *line_to_free = NULL;
+  char c;
   int saved_did_emsg;
   bool saved_wait_return = need_wait_return;
-  char_u *name = NULL;
-  char_u *p;
-  char_u *arg;
-  char_u *line_arg = NULL;
+  char *name = NULL;
+  char *p;
+  char *arg;
+  char *line_arg = NULL;
   garray_T newargs;
   garray_T default_args;
   garray_T newlines;
@@ -1918,14 +1908,12 @@ void ex_function(exarg_T *eap)
   linenr_T sourcing_lnum_off;
   linenr_T sourcing_lnum_top;
   bool is_heredoc = false;
-  char_u *skip_until = NULL;
-  char_u *heredoc_trimmed = NULL;
+  char *skip_until = NULL;
+  char *heredoc_trimmed = NULL;
   bool show_block = false;
   bool do_concat = true;
 
-  /*
-   * ":function" without argument: list functions.
-   */
+  // ":function" without argument: list functions.
   if (ends_excmd(*eap->arg)) {
     if (!eap->skip) {
       todo = (int)func_hashtab.ht_used;
@@ -1933,7 +1921,7 @@ void ex_function(exarg_T *eap)
         if (!HASHITEM_EMPTY(hi)) {
           todo--;
           fp = HI2UF(hi);
-          if (message_filtered(fp->uf_name)) {
+          if (message_filtered((char *)fp->uf_name)) {
             continue;
           }
           if (!func_name_refcount(fp->uf_name)) {
@@ -1942,15 +1930,13 @@ void ex_function(exarg_T *eap)
         }
       }
     }
-    eap->nextcmd = (char *)check_nextcmd((char_u *)eap->arg);
+    eap->nextcmd = check_nextcmd(eap->arg);
     return;
   }
 
-  /*
-   * ":function /pat": list functions matching pattern.
-   */
+  // ":function /pat": list functions matching pattern.
   if (*eap->arg == '/') {
-    p = skip_regexp((char_u *)eap->arg + 1, '/', true, NULL);
+    p = skip_regexp(eap->arg + 1, '/', true, NULL);
     if (!eap->skip) {
       regmatch_T regmatch;
 
@@ -1978,7 +1964,7 @@ void ex_function(exarg_T *eap)
     if (*p == '/') {
       p++;
     }
-    eap->nextcmd = (char *)check_nextcmd(p);
+    eap->nextcmd = check_nextcmd(p);
     return;
   }
 
@@ -1996,15 +1982,20 @@ void ex_function(exarg_T *eap)
   //             "fudi.fd_di" set, "fudi.fd_newkey" == NULL
   // s:func      script-local function name
   // g:func      global function name, same as "func"
-  p = (char_u *)eap->arg;
-  name = trans_function_name((char **)&p, eap->skip, TFN_NO_AUTOLOAD, &fudi, NULL);
-  paren = (vim_strchr((char *)p, '(') != NULL);
+  p = eap->arg;
+  if (strncmp(p, "<lambda>", 8) == 0) {
+    p += 8;
+    (void)getdigits(&p, false, 0);
+    name = xstrndup(eap->arg, (size_t)(p - eap->arg));
+    CLEAR_FIELD(fudi);
+  } else {
+    name = (char *)trans_function_name(&p, eap->skip, TFN_NO_AUTOLOAD, &fudi, NULL);
+  }
+  paren = (vim_strchr(p, '(') != NULL);
   if (name == NULL && (fudi.fd_dict == NULL || !paren) && !eap->skip) {
-    /*
-     * Return on an invalid expression in braces, unless the expression
-     * evaluation has been cancelled due to an aborting error, an
-     * interrupt, or an exception.
-     */
+    // Return on an invalid expression in braces, unless the expression
+    // evaluation has been cancelled due to an aborting error, an
+    // interrupt, or an exception.
     if (!aborting()) {
       if (fudi.fd_newkey != NULL) {
         semsg(_(e_dictkey), fudi.fd_newkey);
@@ -2028,16 +2019,16 @@ void ex_function(exarg_T *eap)
   //  - exclude line numbers from function body
   //
   if (!paren) {
-    if (!ends_excmd(*skipwhite((char *)p))) {
+    if (!ends_excmd(*skipwhite(p))) {
       semsg(_(e_trailing_arg), p);
       goto ret_free;
     }
-    eap->nextcmd = (char *)check_nextcmd(p);
+    eap->nextcmd = check_nextcmd(p);
     if (eap->nextcmd != NULL) {
       *p = NUL;
     }
     if (!eap->skip && !got_int) {
-      fp = find_func(name);
+      fp = find_func((char_u *)name);
       if (fp != NULL) {
         list_func_head(fp, !eap->forceit, eap->forceit);
         for (int j = 0; j < fp->uf_lines.ga_len && !got_int; j++) {
@@ -2054,7 +2045,7 @@ void ex_function(exarg_T *eap)
               msg_putchar(' ');
             }
           }
-          msg_prt_line((char_u *)FUNCLINE(fp, j), false);
+          msg_prt_line(FUNCLINE(fp, j), false);
           ui_flush();                  // show a line at a time
           os_breakcheck();
         }
@@ -2063,27 +2054,25 @@ void ex_function(exarg_T *eap)
           msg_puts(eap->forceit ? "endfunction" : "   endfunction");
         }
       } else {
-        emsg_funcname(N_("E123: Undefined function: %s"), name);
+        emsg_funcname(N_("E123: Undefined function: %s"), (char_u *)name);
       }
     }
     goto ret_free;
   }
 
-  /*
-   * ":function name(arg1, arg2)" Define function.
-   */
-  p = (char_u *)skipwhite((char *)p);
+  // ":function name(arg1, arg2)" Define function.
+  p = skipwhite(p);
   if (*p != '(') {
     if (!eap->skip) {
       semsg(_("E124: Missing '(': %s"), eap->arg);
       goto ret_free;
     }
     // attempt to continue by skipping some text
-    if (vim_strchr((char *)p, '(') != NULL) {
-      p = (char_u *)vim_strchr((char *)p, '(');
+    if (vim_strchr(p, '(') != NULL) {
+      p = vim_strchr(p, '(');
     }
   }
-  p = (char_u *)skipwhite((char *)p + 1);
+  p = skipwhite(p + 1);
 
   ga_init(&newargs, (int)sizeof(char_u *), 3);
   ga_init(&newlines, (int)sizeof(char_u *), 3);
@@ -2094,15 +2083,15 @@ void ex_function(exarg_T *eap)
     if (name != NULL) {
       arg = name;
     } else {
-      arg = fudi.fd_newkey;
+      arg = (char *)fudi.fd_newkey;
     }
     if (arg != NULL && (fudi.fd_di == NULL || !tv_is_func(fudi.fd_di->di_tv))) {
-      int j = (*arg == K_SPECIAL) ? 3 : 0;
+      int j = ((uint8_t)(*arg) == K_SPECIAL) ? 3 : 0;
       while (arg[j] != NUL && (j == 0 ? eval_isnamec1(arg[j]) : eval_isnamec(arg[j]))) {
         j++;
       }
       if (arg[j] != NUL) {
-        emsg_funcname((char *)e_invarg2, arg);
+        emsg_funcname((char *)e_invarg2, (char_u *)arg);
       }
     }
     // Disallow using the g: dict.
@@ -2111,7 +2100,7 @@ void ex_function(exarg_T *eap)
     }
   }
 
-  if (get_function_args((char **)&p, ')', &newargs, &varargs,
+  if (get_function_args(&p, ')', &newargs, &varargs,
                         &default_args, eap->skip) == FAIL) {
     goto errret_2;
   }
@@ -2123,7 +2112,7 @@ void ex_function(exarg_T *eap)
 
   // find extra arguments "range", "dict", "abort" and "closure"
   for (;;) {
-    p = (char_u *)skipwhite((char *)p);
+    p = skipwhite(p);
     if (STRNCMP(p, "range", 5) == 0) {
       flags |= FC_RANGE;
       p += 5;
@@ -2137,9 +2126,8 @@ void ex_function(exarg_T *eap)
       flags |= FC_CLOSURE;
       p += 7;
       if (current_funccal == NULL) {
-        emsg_funcname(N_
-                        ("E932: Closure function should not be at top level: %s"),
-                      name == NULL ? (char_u *)"" : name);
+        emsg_funcname(N_("E932: Closure function should not be at top level: %s"),
+                      name == NULL ? (char_u *)"" : (char_u *)name);
         goto erret;
       }
     } else {
@@ -2155,9 +2143,7 @@ void ex_function(exarg_T *eap)
     semsg(_(e_trailing_arg), p);
   }
 
-  /*
-   * Read the body of the function, until ":endfunction" is found.
-   */
+  // Read the body of the function, until ":endfunction" is found.
   if (KeyTyped) {
     // Check if the function already exists, don't let the user type the
     // whole function before telling him it doesn't work!  For a script we
@@ -2165,8 +2151,8 @@ void ex_function(exarg_T *eap)
     if (!eap->skip && !eap->forceit) {
       if (fudi.fd_dict != NULL && fudi.fd_newkey == NULL) {
         emsg(_(e_funcdict));
-      } else if (name != NULL && find_func(name) != NULL) {
-        emsg_funcname(e_funcexts, name);
+      } else if (name != NULL && find_func((char_u *)name) != NULL) {
+        emsg_funcname(e_funcexts, (char_u *)name);
       }
     }
 
@@ -2195,9 +2181,9 @@ void ex_function(exarg_T *eap)
     if (line_arg != NULL) {
       // Use eap->arg, split up in parts by line breaks.
       theline = line_arg;
-      p = (char_u *)vim_strchr((char *)theline, '\n');
+      p = vim_strchr(theline, '\n');
       if (p == NULL) {
-        line_arg += STRLEN(line_arg);
+        line_arg += strlen(line_arg);
       } else {
         *p = NUL;
         line_arg = p + 1;
@@ -2205,9 +2191,9 @@ void ex_function(exarg_T *eap)
     } else {
       xfree(line_to_free);
       if (eap->getline == NULL) {
-        theline = getcmdline(':', 0L, indent, do_concat);
+        theline = (char *)getcmdline(':', 0L, indent, do_concat);
       } else {
-        theline = (char_u *)eap->getline(':', eap->cookie, indent, do_concat);
+        theline = eap->getline(':', eap->cookie, indent, do_concat);
       }
       line_to_free = theline;
     }
@@ -2237,18 +2223,18 @@ void ex_function(exarg_T *eap)
       // * ":python <<EOF" and "EOF"
       // * ":let {var-name} =<< [trim] {marker}" and "{marker}"
       if (heredoc_trimmed == NULL
-          || (is_heredoc && (char_u *)skipwhite((char *)theline) == theline)
+          || (is_heredoc && skipwhite(theline) == theline)
           || STRNCMP(theline, heredoc_trimmed,
-                     STRLEN(heredoc_trimmed)) == 0) {
+                     strlen(heredoc_trimmed)) == 0) {
         if (heredoc_trimmed == NULL) {
           p = theline;
         } else if (is_heredoc) {
-          p = (char_u *)skipwhite((char *)theline) == theline
-            ? theline : theline + STRLEN(heredoc_trimmed);
+          p = skipwhite(theline) == theline
+            ? theline : theline + strlen(heredoc_trimmed);
         } else {
-          p = theline + STRLEN(heredoc_trimmed);
+          p = theline + strlen(heredoc_trimmed);
         }
-        if (STRCMP(p, skip_until) == 0) {
+        if (strcmp(p, skip_until) == 0) {
           XFREE_CLEAR(skip_until);
           XFREE_CLEAR(heredoc_trimmed);
           do_concat = true;
@@ -2260,27 +2246,26 @@ void ex_function(exarg_T *eap)
       for (p = theline; ascii_iswhite(*p) || *p == ':'; p++) {}
 
       // Check for "endfunction".
-      if (checkforcmd((char **)&p, "endfunction", 4) && nesting-- == 0) {
+      if (checkforcmd(&p, "endfunction", 4) && nesting-- == 0) {
         if (*p == '!') {
           p++;
         }
-        char_u *nextcmd = NULL;
+        char *nextcmd = NULL;
         if (*p == '|') {
           nextcmd = p + 1;
-        } else if (line_arg != NULL && *skipwhite((char *)line_arg) != NUL) {
+        } else if (line_arg != NULL && *skipwhite(line_arg) != NUL) {
           nextcmd = line_arg;
         } else if (*p != NUL && *p != '"' && p_verbose > 0) {
-          give_warning2((char_u *)_("W22: Text found after :endfunction: %s"),
-                        p, true);
+          give_warning2(_("W22: Text found after :endfunction: %s"), p, true);
         }
         if (nextcmd != NULL) {
           // Another command follows. If the line came from "eap" we
           // can simply point into it, otherwise we need to change
           // "eap->cmdlinep".
-          eap->nextcmd = (char *)nextcmd;
+          eap->nextcmd = nextcmd;
           if (line_to_free != NULL) {
             xfree(*eap->cmdlinep);
-            *eap->cmdlinep = (char *)line_to_free;
+            *eap->cmdlinep = line_to_free;
             line_to_free = NULL;
           }
         }
@@ -2299,13 +2284,13 @@ void ex_function(exarg_T *eap)
       }
 
       // Check for defining a function inside this function.
-      if (checkforcmd((char **)&p, "function", 2)) {
+      if (checkforcmd(&p, "function", 2)) {
         if (*p == '!') {
-          p = (char_u *)skipwhite((char *)p + 1);
+          p = skipwhite(p + 1);
         }
         p += eval_fname_script((const char *)p);
-        xfree(trans_function_name((char **)&p, true, 0, NULL, NULL));
-        if (*skipwhite((char *)p) == '(') {
+        xfree(trans_function_name(&p, true, 0, NULL, NULL));
+        if (*skipwhite(p) == '(') {
           if (nesting == MAX_FUNC_NESTING - 1) {
             emsg(_("E1058: function nesting too deep"));
           } else {
@@ -2316,7 +2301,7 @@ void ex_function(exarg_T *eap)
       }
 
       // Check for ":append", ":change", ":insert".
-      p = (char_u *)skip_range((char *)p, NULL);
+      p = skip_range(p, NULL);
       if ((p[0] == 'a' && (!ASCII_ISALPHA(p[1]) || p[1] == 'p'))
           || (p[0] == 'c'
               && (!ASCII_ISALPHA(p[1])
@@ -2328,11 +2313,11 @@ void ex_function(exarg_T *eap)
               && (!ASCII_ISALPHA(p[1]) || (p[1] == 'n'
                                            && (!ASCII_ISALPHA(p[2])
                                                || (p[2] == 's')))))) {
-        skip_until = vim_strsave((char_u *)".");
+        skip_until = xstrdup(".");
       }
 
       // heredoc: Check for ":python <<EOF", ":lua <<EOF", etc.
-      arg = (char_u *)skipwhite((char *)skiptowhite(p));
+      arg = skipwhite(skiptowhite(p));
       if (arg[0] == '<' && arg[1] == '<'
           && ((p[0] == 'p' && p[1] == 'y'
                && (!ASCII_ISALNUM(p[2]) || p[2] == 't'
@@ -2349,22 +2334,22 @@ void ex_function(exarg_T *eap)
               || (p[0] == 'm' && p[1] == 'z'
                   && (!ASCII_ISALPHA(p[2]) || p[2] == 's')))) {
         // ":python <<" continues until a dot, like ":append"
-        p = (char_u *)skipwhite((char *)arg + 2);
+        p = skipwhite(arg + 2);
         if (*p == NUL) {
-          skip_until = vim_strsave((char_u *)".");
+          skip_until = xstrdup(".");
         } else {
-          skip_until = vim_strsave(p);
+          skip_until = xstrdup(p);
         }
       }
 
       // Check for ":let v =<< [trim] EOF"
       //       and ":let [a, b] =<< [trim] EOF"
-      arg = (char_u *)skipwhite((char *)skiptowhite(p));
+      arg = skipwhite(skiptowhite(p));
       if (*arg == '[') {
-        arg = (char_u *)vim_strchr((char *)arg, ']');
+        arg = vim_strchr(arg, ']');
       }
       if (arg != NULL) {
-        arg = (char_u *)skipwhite((char *)skiptowhite(arg));
+        arg = skipwhite(skiptowhite(arg));
         if (arg[0] == '='
             && arg[1] == '<'
             && arg[2] == '<'
@@ -2372,14 +2357,13 @@ void ex_function(exarg_T *eap)
                 && p[1] == 'e'
                 && (!ASCII_ISALNUM(p[2])
                     || (p[2] == 't' && !ASCII_ISALNUM(p[3]))))) {
-          p = (char_u *)skipwhite((char *)arg + 3);
+          p = skipwhite(arg + 3);
           if (STRNCMP(p, "trim", 4) == 0) {
             // Ignore leading white space.
-            p = (char_u *)skipwhite((char *)p + 4);
-            heredoc_trimmed =
-              vim_strnsave(theline, (size_t)((char_u *)skipwhite((char *)theline) - theline));
+            p = skipwhite(p + 4);
+            heredoc_trimmed = xstrnsave(theline, (size_t)(skipwhite(theline) - theline));
           }
-          skip_until = vim_strnsave(p, (size_t)(skiptowhite(p) - p));
+          skip_until = xstrnsave(p, (size_t)(skiptowhite(p) - p));
           do_concat = false;
           is_heredoc = true;
         }
@@ -2392,8 +2376,8 @@ void ex_function(exarg_T *eap)
     // Copy the line to newly allocated memory.  get_one_sourceline()
     // allocates 250 bytes per line, this saves 80% on average.  The cost
     // is an extra alloc/free.
-    p = vim_strsave(theline);
-    ((char **)(newlines.ga_data))[newlines.ga_len++] = (char *)p;
+    p = xstrdup(theline);
+    ((char **)(newlines.ga_data))[newlines.ga_len++] = p;
 
     // Add NULL lines for continuation lines, so that the line count is
     // equal to the index in the growarray.
@@ -2413,30 +2397,28 @@ void ex_function(exarg_T *eap)
     goto erret;
   }
 
-  /*
-   * If there are no errors, add the function
-   */
+  // If there are no errors, add the function
   if (fudi.fd_dict == NULL) {
-    v = find_var((const char *)name, STRLEN(name), &ht, false);
+    v = find_var((const char *)name, strlen(name), &ht, false);
     if (v != NULL && v->di_tv.v_type == VAR_FUNC) {
       emsg_funcname(N_("E707: Function name conflicts with variable: %s"),
-                    name);
+                    (char_u *)name);
       goto erret;
     }
 
-    fp = find_func(name);
+    fp = find_func((char_u *)name);
     if (fp != NULL) {
       // Function can be replaced with "function!" and when sourcing the
       // same script again, but only once.
       if (!eap->forceit
           && (fp->uf_script_ctx.sc_sid != current_sctx.sc_sid
               || fp->uf_script_ctx.sc_seq == current_sctx.sc_seq)) {
-        emsg_funcname(e_funcexts, name);
+        emsg_funcname(e_funcexts, (char_u *)name);
         goto erret;
       }
       if (fp->uf_calls > 0) {
         emsg_funcname(N_("E127: Cannot redefine function %s: It is in use"),
-                      name);
+                      (char_u *)name);
         goto erret;
       }
       if (fp->uf_refcount > 1) {
@@ -2480,23 +2462,23 @@ void ex_function(exarg_T *eap)
     // Give the function a sequential number.  Can only be used with a
     // Funcref!
     xfree(name);
-    sprintf(numbuf, "%d", ++func_nr);
-    name = vim_strsave((char_u *)numbuf);
+    sprintf(numbuf, "%d", ++func_nr);  // NOLINT(runtime/printf)
+    name = xstrdup(numbuf);
   }
 
   if (fp == NULL) {
-    if (fudi.fd_dict == NULL && vim_strchr((char *)name, AUTOLOAD_CHAR) != NULL) {
+    if (fudi.fd_dict == NULL && vim_strchr(name, AUTOLOAD_CHAR) != NULL) {
       int slen, plen;
       char_u *scriptname;
 
       // Check that the autoload name matches the script name.
       int j = FAIL;
       if (SOURCING_NAME != NULL) {
-        scriptname = (char_u *)autoload_name((const char *)name, STRLEN(name));
-        p = (char_u *)vim_strchr((char *)scriptname, '/');
+        scriptname = (char_u *)autoload_name((const char *)name, strlen(name));
+        p = vim_strchr((char *)scriptname, '/');
         plen = (int)STRLEN(p);
         slen = (int)STRLEN(SOURCING_NAME);
-        if (slen > plen && FNAMECMP(p, SOURCING_NAME + slen - plen) == 0) {
+        if (slen > plen && path_fnamecmp(p, SOURCING_NAME + slen - plen) == 0) {
           j = OK;
         }
         xfree(scriptname);
@@ -2508,7 +2490,7 @@ void ex_function(exarg_T *eap)
       }
     }
 
-    fp = xcalloc(1, offsetof(ufunc_T, uf_name) + STRLEN(name) + 1);
+    fp = xcalloc(1, offsetof(ufunc_T, uf_name) + strlen(name) + 1);
 
     if (fudi.fd_dict != NULL) {
       if (fudi.fd_di == NULL) {
@@ -2524,16 +2506,16 @@ void ex_function(exarg_T *eap)
         tv_clear(&fudi.fd_di->di_tv);
       }
       fudi.fd_di->di_tv.v_type = VAR_FUNC;
-      fudi.fd_di->di_tv.vval.v_string = (char *)vim_strsave(name);
+      fudi.fd_di->di_tv.vval.v_string = xstrdup(name);
 
       // behave like "dict" was used
       flags |= FC_DICT;
     }
 
     // insert the new function in the function list
-    set_ufunc_name(fp, name);
+    set_ufunc_name(fp, (char_u *)name);
     if (overwrite) {
-      hi = hash_find(&func_hashtab, (char *)name);
+      hi = hash_find(&func_hashtab, name);
       hi->hi_key = UF2HIKEY(fp);
     } else if (hash_add(&func_hashtab, UF2HIKEY(fp)) == FAIL) {
       xfree(fp);
@@ -2590,8 +2572,8 @@ int eval_fname_script(const char *const p)
   // Use mb_strnicmp() because in Turkish comparing the "I" may not work with
   // the standard library function.
   if (p[0] == '<'
-      && (mb_strnicmp((char_u *)p + 1, (char_u *)"SID>", 4) == 0
-          || mb_strnicmp((char_u *)p + 1, (char_u *)"SNR>", 4) == 0)) {
+      && (mb_strnicmp(p + 1, "SID>", 4) == 0
+          || mb_strnicmp(p + 1, "SNR>", 4) == 0)) {
     return 5;
   }
   if (p[0] == 's' && p[1] == ':') {
@@ -2666,7 +2648,7 @@ char *get_user_func_name(expand_T *xp, int idx)
       return (char *)fp->uf_name;  // Prevent overflow.
     }
 
-    cat_func_name(IObuff, fp);
+    cat_func_name((char_u *)IObuff, fp);
     if (xp->xp_context != EXPAND_USER_FUNC) {
       STRCAT(IObuff, "(");
       if (!fp->uf_varargs && GA_EMPTY(&fp->uf_args)) {
@@ -2700,7 +2682,7 @@ void ex_delfunction(exarg_T *eap)
     semsg(_(e_trailing_arg), p);
     return;
   }
-  eap->nextcmd = (char *)check_nextcmd(p);
+  eap->nextcmd = check_nextcmd((char *)p);
   if (eap->nextcmd != NULL) {
     *p = NUL;
   }
@@ -2889,7 +2871,7 @@ void ex_return(exarg_T *eap)
   if (returning) {
     eap->nextcmd = NULL;
   } else if (eap->nextcmd == NULL) {          // no argument
-    eap->nextcmd = (char *)check_nextcmd(arg);
+    eap->nextcmd = check_nextcmd((char *)arg);
   }
 
   if (eap->skip) {
@@ -2975,12 +2957,12 @@ void ex_call(exarg_T *eap)
     arg = startarg;
 
     funcexe_T funcexe = FUNCEXE_INIT;
-    funcexe.firstline = eap->line1;
-    funcexe.lastline = eap->line2;
-    funcexe.doesrange = &doesrange;
-    funcexe.evaluate = true;
-    funcexe.partial = partial;
-    funcexe.selfdict = fudi.fd_dict;
+    funcexe.fe_firstline = eap->line1;
+    funcexe.fe_lastline = eap->line2;
+    funcexe.fe_doesrange = &doesrange;
+    funcexe.fe_evaluate = true;
+    funcexe.fe_partial = partial;
+    funcexe.fe_selfdict = fudi.fd_dict;
     if (get_func_tv(name, -1, &rettv, (char **)&arg, &funcexe) == FAIL) {
       failed = true;
       break;
@@ -3010,7 +2992,7 @@ void ex_call(exarg_T *eap)
 
   // When inside :try we need to check for following "| catch" or "| endtry".
   // Not when there was an error, but do check if an exception was thrown.
-  if ((!aborting() || current_exception != NULL) && (!failed || eap->cstack->cs_trylevel > 0)) {
+  if ((!aborting() || did_throw) && (!failed || eap->cstack->cs_trylevel > 0)) {
     // Check for trailing illegal characters and a following command.
     if (!ends_excmd(*arg)) {
       if (!failed && !aborting()) {
@@ -3018,7 +3000,7 @@ void ex_call(exarg_T *eap)
         semsg(_(e_trailing_arg), arg);
       }
     } else {
-      eap->nextcmd = (char *)check_nextcmd(arg);
+      eap->nextcmd = check_nextcmd((char *)arg);
     }
   }
 
@@ -3105,25 +3087,25 @@ int do_return(exarg_T *eap, int reanimate, int is_cmd, void *rettv)
 
 /// Generate a return command for producing the value of "rettv".  The result
 /// is an allocated string.  Used by report_pending() for verbose messages.
-char_u *get_return_cmd(void *rettv)
+char *get_return_cmd(void *rettv)
 {
-  char_u *s = NULL;
-  char_u *tofree = NULL;
+  char *s = NULL;
+  char *tofree = NULL;
 
   if (rettv != NULL) {
-    tofree = s = (char_u *)encode_tv2echo((typval_T *)rettv, NULL);
+    tofree = s = encode_tv2echo((typval_T *)rettv, NULL);
   }
   if (s == NULL) {
-    s = (char_u *)"";
+    s = "";
   }
 
   STRCPY(IObuff, ":return ");
   STRLCPY(IObuff + 8, s, IOSIZE - 8);
-  if (STRLEN(s) + 8 >= IOSIZE) {
+  if (strlen(s) + 8 >= IOSIZE) {
     STRCPY(IObuff + IOSIZE - 4, "...");
   }
   xfree(tofree);
-  return vim_strsave(IObuff);
+  return xstrdup((char *)IObuff);
 }
 
 /// Get next function line.
@@ -3134,12 +3116,12 @@ char *get_func_line(int c, void *cookie, int indent, bool do_concat)
 {
   funccall_T *fcp = (funccall_T *)cookie;
   ufunc_T *fp = fcp->func;
-  char_u *retval;
+  char *retval;
   garray_T *gap;    // growarray with function lines
 
   // If breakpoints have been added/deleted need to check for it.
   if (fcp->dbg_tick != debug_tick) {
-    fcp->breakpoint = dbg_find_breakpoint(false, fp->uf_name, SOURCING_LNUM);
+    fcp->breakpoint = dbg_find_breakpoint(false, (char *)fp->uf_name, SOURCING_LNUM);
     fcp->dbg_tick = debug_tick;
   }
   if (do_profiling == PROF_YES) {
@@ -3159,7 +3141,7 @@ char *get_func_line(int c, void *cookie, int indent, bool do_concat)
     if (fcp->linenr >= gap->ga_len) {
       retval = NULL;
     } else {
-      retval = (char_u *)xstrdup(((char **)(gap->ga_data))[fcp->linenr++]);
+      retval = xstrdup(((char **)(gap->ga_data))[fcp->linenr++]);
       SOURCING_LNUM = fcp->linenr;
       if (do_profiling == PROF_YES) {
         func_line_start(cookie);
@@ -3169,13 +3151,13 @@ char *get_func_line(int c, void *cookie, int indent, bool do_concat)
 
   // Did we encounter a breakpoint?
   if (fcp->breakpoint != 0 && fcp->breakpoint <= SOURCING_LNUM) {
-    dbg_breakpoint(fp->uf_name, SOURCING_LNUM);
+    dbg_breakpoint((char *)fp->uf_name, SOURCING_LNUM);
     // Find next breakpoint.
-    fcp->breakpoint = dbg_find_breakpoint(false, fp->uf_name, SOURCING_LNUM);
+    fcp->breakpoint = dbg_find_breakpoint(false, (char *)fp->uf_name, SOURCING_LNUM);
     fcp->dbg_tick = debug_tick;
   }
 
-  return (char *)retval;
+  return retval;
 }
 
 /// @return  true if the currently active function should be ended, because a
@@ -3211,9 +3193,9 @@ void make_partial(dict_T *const selfdict, typval_T *const rettv)
   } else {
     fname = rettv->v_type == VAR_FUNC || rettv->v_type == VAR_STRING
                                       ? (char_u *)rettv->vval.v_string
-                                      : rettv->vval.v_partial->pt_name;
+                                      : (char_u *)rettv->vval.v_partial->pt_name;
     // Translate "s:func" to the stored function name.
-    fname = fname_trans_sid(fname, fname_buf, &tofree, &error);
+    fname = (char_u *)fname_trans_sid((char *)fname, (char *)fname_buf, (char **)&tofree, &error);
     fp = find_func(fname);
     xfree(tofree);
   }
@@ -3227,7 +3209,7 @@ void make_partial(dict_T *const selfdict, typval_T *const rettv)
     pt->pt_auto = true;
     if (rettv->v_type == VAR_FUNC || rettv->v_type == VAR_STRING) {
       // Just a function: Take over the function name and use selfdict.
-      pt->pt_name = (char_u *)rettv->vval.v_string;
+      pt->pt_name = rettv->vval.v_string;
     } else {
       partial_T *ret_pt = rettv->vval.v_partial;
       int i;
@@ -3236,8 +3218,8 @@ void make_partial(dict_T *const selfdict, typval_T *const rettv)
       // args. Can't take over name or args, the partial might
       // be referenced elsewhere.
       if (ret_pt->pt_name != NULL) {
-        pt->pt_name = vim_strsave(ret_pt->pt_name);
-        func_ref(pt->pt_name);
+        pt->pt_name = xstrdup(ret_pt->pt_name);
+        func_ref((char_u *)pt->pt_name);
       } else {
         pt->pt_func = ret_pt->pt_func;
         func_ptr_ref(pt->pt_func);
@@ -3549,7 +3531,7 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
 {
   ufunc_T *fp = fp_in;
   funccall_T *fc;
-  int error = ERROR_NONE;
+  int error = FCERR_NONE;
   char_u fname_buf[FLEN_FIXED + 1];
   char_u *tofree = NULL;
   char_u *fname;
@@ -3559,7 +3541,7 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
   }
 
   if (fp_in == NULL) {
-    fname = fname_trans_sid(name, fname_buf, &tofree, &error);
+    fname = (char_u *)fname_trans_sid((char *)name, (char *)fname_buf, (char **)&tofree, &error);
     fp = find_func(fname);
   }
   if (fp != NULL) {
@@ -3571,20 +3553,18 @@ bool set_ref_in_func(char_u *name, ufunc_T *fp_in, int copyID)
   return abort;
 }
 
-/// Registers a C extension user function.
-char_u *register_cfunc(cfunc_T cb, cfunc_free_T cb_free, void *state)
+/// Registers a luaref as a lambda.
+char_u *register_luafunc(LuaRef ref)
 {
   char_u *name = get_lambda_name();
   ufunc_T *fp = xcalloc(1, offsetof(ufunc_T, uf_name) + STRLEN(name) + 1);
 
   fp->uf_refcount = 1;
   fp->uf_varargs = true;
-  fp->uf_flags = FC_CFUNC;
+  fp->uf_flags = FC_LUAREF;
   fp->uf_calls = 0;
   fp->uf_script_ctx = current_sctx;
-  fp->uf_cb = cb;
-  fp->uf_cb_free = cb_free;
-  fp->uf_cb_state = state;
+  fp->uf_luaref = ref;
 
   STRCPY(fp->uf_name, name);
   hash_add(&func_hashtab, UF2HIKEY(fp));
diff --git a/src/nvim/eval/userfunc.h b/src/nvim/eval/userfunc.h
index 4b7007aae9..4098622a14 100644
--- a/src/nvim/eval/userfunc.h
+++ b/src/nvim/eval/userfunc.h
@@ -9,6 +9,20 @@
 #define HIKEY2UF(p)  ((ufunc_T *)(p - offsetof(ufunc_T, uf_name)))
 #define HI2UF(hi)    HIKEY2UF((hi)->hi_key)
 
+// flags used in uf_flags
+#define FC_ABORT    0x01          // abort function on error
+#define FC_RANGE    0x02          // function accepts range
+#define FC_DICT     0x04          // Dict function, uses "self"
+#define FC_CLOSURE  0x08          // closure, uses outer scope variables
+#define FC_DELETED  0x10          // :delfunction used while uf_refcount > 0
+#define FC_REMOVED  0x20          // function redefined while uf_refcount > 0
+#define FC_SANDBOX  0x40          // function defined in the sandbox
+#define FC_DEAD     0x80          // function kept only for reference to dfunc
+#define FC_EXPORT   0x100         // "export def Func()"
+#define FC_NOARGS   0x200         // no a: variables in lambda
+#define FC_VIM9     0x400         // defined in vim9 script file
+#define FC_LUAREF  0x800          // luaref callback
+
 ///< Structure used by trans_function_name()
 typedef struct {
   dict_T *fd_dict;  ///< Dictionary used.
@@ -24,44 +38,43 @@ struct funccal_entry {
 
 /// errors for when calling a function
 typedef enum {
-  ERROR_UNKNOWN = 0,
-  ERROR_TOOMANY,
-  ERROR_TOOFEW,
-  ERROR_SCRIPT,
-  ERROR_DICT,
-  ERROR_NONE,
-  ERROR_OTHER,
-  ERROR_BOTH,
-  ERROR_DELETED,
-  ERROR_NOTMETHOD,
+  FCERR_UNKNOWN = 0,
+  FCERR_TOOMANY = 1,
+  FCERR_TOOFEW = 2,
+  FCERR_SCRIPT = 3,
+  FCERR_DICT = 4,
+  FCERR_NONE = 5,
+  FCERR_OTHER = 6,
+  FCERR_DELETED = 7,
+  FCERR_NOTMETHOD = 8,  ///< function cannot be used as a method
 } FnameTransError;
 
 /// Used in funcexe_T. Returns the new argcount.
-typedef int (*ArgvFunc)(int current_argcount, typval_T *argv, int argskip,
-                        int called_func_argcount);
+typedef int (*ArgvFunc)(int current_argcount, typval_T *argv, int partial_argcount,
+                        ufunc_T *called_func);
 
 /// Structure passed between functions dealing with function call execution.
 typedef struct {
-  ArgvFunc argv_func;  ///< when not NULL, can be used to fill in arguments only
-                       ///< when the invoked function uses them
-  linenr_T firstline;  ///< first line of range
-  linenr_T lastline;   ///< last line of range
-  bool *doesrange;     ///< [out] if not NULL: function handled range
-  bool evaluate;       ///< actually evaluate expressions
-  partial_T *partial;  ///< for extra arguments
-  dict_T *selfdict;    ///< Dictionary for "self"
-  typval_T *basetv;    ///< base for base->method()
+  ArgvFunc fe_argv_func;  ///< when not NULL, can be used to fill in arguments only
+                          ///< when the invoked function uses them
+  linenr_T fe_firstline;  ///< first line of range
+  linenr_T fe_lastline;   ///< last line of range
+  bool *fe_doesrange;     ///< [out] if not NULL: function handled range
+  bool fe_evaluate;       ///< actually evaluate expressions
+  partial_T *fe_partial;  ///< for extra arguments
+  dict_T *fe_selfdict;    ///< Dictionary for "self"
+  typval_T *fe_basetv;    ///< base for base->method()
 } funcexe_T;
 
 #define FUNCEXE_INIT (funcexe_T) { \
-  .argv_func = NULL, \
-  .firstline = 0, \
-  .lastline = 0, \
-  .doesrange = NULL, \
-  .evaluate = false, \
-  .partial = NULL, \
-  .selfdict = NULL, \
-  .basetv = NULL, \
+  .fe_argv_func = NULL, \
+  .fe_firstline = 0, \
+  .fe_lastline = 0, \
+  .fe_doesrange = NULL, \
+  .fe_evaluate = false, \
+  .fe_partial = NULL, \
+  .fe_selfdict = NULL, \
+  .fe_basetv = NULL, \
 }
 
 #define FUNCARG(fp, j)  ((char **)(fp->uf_args.ga_data))[j]
diff --git a/src/nvim/eval/vars.c b/src/nvim/eval/vars.c
index 0086cc41ca..4d7214205d 100644
--- a/src/nvim/eval/vars.c
+++ b/src/nvim/eval/vars.c
@@ -81,7 +81,7 @@ static list_T *heredoc_get(exarg_T *eap, char *cmd)
   // The marker is the next word.
   if (*cmd != NUL && *cmd != '"') {
     marker = skipwhite(cmd);
-    p = (char *)skiptowhite((char_u *)marker);
+    p = skiptowhite(marker);
     if (*skipwhite(p) != NUL && *skipwhite(p) != '"') {
       semsg(_(e_trailing_arg), p);
       return NULL;
@@ -113,7 +113,7 @@ static list_T *heredoc_get(exarg_T *eap, char *cmd)
         && STRNCMP(theline, *eap->cmdlinep, marker_indent_len) == 0) {
       mi = marker_indent_len;
     }
-    if (STRCMP(marker, theline + mi) == 0) {
+    if (strcmp(marker, theline + mi) == 0) {
       xfree(theline);
       break;
     }
@@ -207,7 +207,7 @@ static void ex_let_const(exarg_T *eap, const bool is_const)
       list_func_vars(&first);
       list_vim_vars(&first);
     }
-    eap->nextcmd = (char *)check_nextcmd((char_u *)arg);
+    eap->nextcmd = check_nextcmd(arg);
   } else if (expr[0] == '=' && expr[1] == '<' && expr[2] == '<') {
     // HERE document
     list_T *l = heredoc_get(eap, expr + 3);
@@ -413,7 +413,7 @@ void list_hashtable_vars(hashtab_T *ht, const char *prefix, int empty, int *firs
       // apply :filter /pat/ to variable name
       xstrlcpy(buf, prefix, IOSIZE);
       xstrlcat(buf, (char *)di->di_key, IOSIZE);
-      if (message_filtered((char_u *)buf)) {
+      if (message_filtered(buf)) {
         continue;
       }
 
@@ -587,7 +587,7 @@ static char *ex_let_one(char *arg, typval_T *const tv, const bool copy, const bo
           char *s = vim_getenv(name);
 
           if (s != NULL) {
-            tofree = (char *)concat_str((const char_u *)s, (const char_u *)p);
+            tofree = concat_str(s, p);
             p = (const char *)tofree;
             xfree(s);
           }
@@ -663,8 +663,7 @@ static char *ex_let_one(char *arg, typval_T *const tv, const bool copy, const bo
           } else if (opt_type == gov_string && stringval != NULL && s != NULL) {
             // string
             char *const oldstringval = stringval;
-            stringval = (char *)concat_str((const char_u *)stringval,
-                                           (const char_u *)s);
+            stringval = concat_str(stringval, s);
             xfree(oldstringval);
             s = stringval;
           }
@@ -705,14 +704,13 @@ static char *ex_let_one(char *arg, typval_T *const tv, const bool copy, const bo
       if (p != NULL && op != NULL && *op == '.') {
         s = get_reg_contents(*arg == '@' ? '"' : *arg, kGRegExprSrc);
         if (s != NULL) {
-          ptofree = (char *)concat_str((char_u *)s, (const char_u *)p);
+          ptofree = concat_str(s, p);
           p = (const char *)ptofree;
           xfree(s);
         }
       }
       if (p != NULL) {
-        write_reg_contents(*arg == '@' ? '"' : *arg,
-                           (const char_u *)p, (ssize_t)STRLEN(p), false);
+        write_reg_contents(*arg == '@' ? '"' : *arg, p, (ssize_t)strlen(p), false);
         arg_end = arg + 1;
       }
       xfree(ptofree);
@@ -826,7 +824,7 @@ static void ex_unletlock(exarg_T *eap, char *argstart, int deep, ex_unletlock_ca
     arg = skipwhite(name_end);
   } while (!ends_excmd(*arg));
 
-  eap->nextcmd = (char *)check_nextcmd((char_u *)arg);
+  eap->nextcmd = check_nextcmd(arg);
 }
 
 // TODO(ZyX-I): move to eval/ex_cmds
@@ -1350,12 +1348,8 @@ void set_var_const(const char *name, const size_t name_len, typval_T *const tv,
   }
 
   if (watched) {
-    if (oldtv.v_type == VAR_UNKNOWN) {
-      tv_dict_watcher_notify(dict, (char *)v->di_key, &v->di_tv, NULL);
-    } else {
-      tv_dict_watcher_notify(dict, (char *)v->di_key, &v->di_tv, &oldtv);
-      tv_clear(&oldtv);
-    }
+    tv_dict_watcher_notify(dict, (char *)v->di_key, &v->di_tv, &oldtv);
+    tv_clear(&oldtv);
   }
 
   if (is_const) {
@@ -1803,7 +1797,7 @@ void f_setbufvar(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
       // reset notion of buffer
       aucmd_restbuf(&aco);
     } else {
-      const size_t varname_len = STRLEN(varname);
+      const size_t varname_len = strlen(varname);
       char *const bufvarname = xmalloc(varname_len + 3);
       buf_T *const save_curbuf = curbuf;
       curbuf = buf;