vim-patch:8.1.1803: all builtin functions are global

Problem:    All builtin functions are global.
Solution:   Add the method call operator ->.  Implemented for a limited number
            of functions.
ac92e25a33

- Note that to *exactly* port hunk @@ -7376,18 +7444,19 from
  handle_subscript(), we need the :scriptversion patches (I have an open
  PR for those, but this patch works fine without them anyway).
- Port call_internal_func() from v7.4.2058.
- Adjust some error messages in tests, as they rely on the Blob patches.
- Add a modeline to test_method.vim.

Ignore the global_functions and base_method tables and prefer the
current GPerf implementation. Instead, add an extra base_arg field to
VimLFuncDef that holds the number of the argument to use as the base
(1-indexed, so that 0 may be used to refer to functions that cannot be
used as methods).

This also means we support using any argument as a base from the get-go,
rather than just the first (Vim includes this ability in future patches,
however).

To mark a function as usable as a method, use the "base" key as
described in eval.lua.

runtime/doc/eval.txt

@@ -942,6 +942,8 @@ in any order.  E.g., these are all possible:
 	expr9[expr1].name
 	expr9.name[expr1]
 	expr9(expr1, ...)[expr1].name
+	expr9->(expr1, ...)[expr1]
+Evaluation is always from left to right.
 
 
 expr8[expr1]		item of String or |List|	*expr-[]* *E111*
@@ -1043,6 +1045,11 @@ expr8(expr1, ...)	|Funcref| function call
 When expr8 is a |Funcref| type variable, invoke the function it refers to.
 
 
+expr8->name([args])	method call			*method*
+
+For global methods this is the same as: >
+	name(expr8 [, args])
+There can also be methods specifically for the type of "expr8".
 
 							*expr9*
 number
@@ -2603,6 +2610,8 @@ add({list}, {expr})					*add()*
 <		Note that when {expr} is a |List| it is appended as a single
 		item.  Use |extend()| to concatenate |Lists|.
 		Use |insert()| to add an item at another position.
+		Can also be used as a |method|: >
+			mylist->add(val1)->add(val2)
 
 
 and({expr}, {expr})					*and()*
@@ -3215,6 +3224,8 @@ copy({expr})	Make a copy of {expr}.  For Numbers and Strings this isn't
 		changing an item changes the contents of both |Lists|.
 		A |Dictionary| is copied in a similar way as a |List|.
 		Also see |deepcopy()|.
+		Can also be used as a |method|: >
+			mylist->copy()
 
 cos({expr})						*cos()*
 		Return the cosine of {expr}, measured in radians, as a |Float|.
@@ -3249,6 +3260,8 @@ count({comp}, {expr} [, {ic} [, {start}]])			*count()*
 		When {comp} is a string then the number of not overlapping
 		occurrences of {expr} is returned. Zero is returned when
 		{expr} is an empty string.
+		Can also be used as a |method|: >
+			mylist->count(val)
 
 							*cscope_connection()*
 cscope_connection([{num} , {dbpath} [, {prepend}]])
@@ -3479,6 +3492,8 @@ empty({expr})						*empty()*
 		A |List| or |Dictionary| is empty when it does not have any
 		items.  A Number is empty when its value is zero.  Special
 		variable is empty when it is |v:false| or |v:null|.
+		Can also be used as a |method|: >
+			mylist->empty()
 
 environ()						*environ()*
 		Return all of environment variables as dictionary. You can
@@ -3794,6 +3809,8 @@ extend({expr1}, {expr2} [, {expr3}])			*extend()*
 		fails.
 		Returns {expr1}.
 
+		Can also be used as a |method|: >
+			mylist->extend(otherlist)
 
 feedkeys({string} [, {mode}])				*feedkeys()*
 		Characters in {string} are queued for processing as if they
@@ -3903,6 +3920,8 @@ filter({expr1}, {expr2})					*filter()*
 		Funcref errors inside a function are ignored, unless it was
 		defined with the "abort" flag.
 
+		Can also be used as a |method|: >
+			mylist->filter(expr2)
 
 finddir({name} [, {path} [, {count}]])				*finddir()*
 		Find directory {name} in {path}.  Supports both downwards and
@@ -4159,6 +4178,8 @@ get({list}, {idx} [, {default}])			*get()*
 		Get item {idx} from |List| {list}.  When this item is not
 		available return {default}.  Return zero when {default} is
 		omitted.
+		Can also be used as a |method|: >
+			mylist->get(idx)
 get({dict}, {key} [, {default}])
 		Get item with key {key} from |Dictionary| {dict}.  When this
 		item is not available return {default}.  Return zero when
@@ -5513,6 +5534,9 @@ insert({list}, {item} [, {idx}])			*insert()*
 		Note that when {item} is a |List| it is inserted as a single
 		item.  Use |extend()| to concatenate |Lists|.
 
+		Can also be used as a |method|: >
+			mylist->insert(item)
+
 interrupt()						*interrupt()*
 		Interrupt script execution.  It works more or less like the
 		user typing CTRL-C, most commands won't execute and control
@@ -5580,6 +5604,8 @@ items({dict})						*items()*
 		|List| item is a list with two items: the key of a {dict}
 		entry and the value of this entry.  The |List| is in arbitrary
 		order.
+		Can also be used as a |method|: >
+			mydict->items()
 
 isnan({expr})						*isnan()*
 		Return |TRUE| if {expr} is a float with value NaN. >
@@ -5713,6 +5739,9 @@ join({list} [, {sep}])					*join()*
 		converted into a string like with |string()|.
 		The opposite function is |split()|.
 
+		Can also be used as a |method|: >
+			mylist->join()
+
 json_decode({expr})					*json_decode()*
 		Convert {expr} from JSON object.  Accepts |readfile()|-style
 		list as the input, as well as regular string.  May output any
@@ -5743,8 +5772,10 @@ json_encode({expr})					*json_encode()*
 keys({dict})						*keys()*
 		Return a |List| with all the keys of {dict}.  The |List| is in
 		arbitrary order.
+		Can also be used as a |method|: >
+			mydict->keys()
 
-							*len()* *E701*
+<							*len()* *E701*
 len({expr})	The result is a Number, which is the length of the argument.
 		When {expr} is a String or a Number the length in bytes is
 		used, as with |strlen()|.
@@ -5755,7 +5786,10 @@ len({expr})	The result is a Number, which is the length of the argument.
 		|Dictionary| is returned.
 		Otherwise an error is given.
 
-						*libcall()* *E364* *E368*
+		Can also be used as a |method|: >
+			mylist->len()
+
+<						*libcall()* *E364* *E368*
 libcall({libname}, {funcname}, {argument})
 		Call function {funcname} in the run-time library {libname}
 		with single argument {argument}.
@@ -5938,6 +5972,8 @@ map({expr1}, {expr2})					*map()*
 		Funcref errors inside a function are ignored, unless it was
 		defined with the "abort" flag.
 
+		Can also be used as a |method|: >
+			mylist->map(expr2)
 
 maparg({name} [, {mode} [, {abbr} [, {dict}]]])			*maparg()*
 		When {dict} is omitted or zero: Return the rhs of mapping
@@ -6273,6 +6309,9 @@ max({expr})	Return the maximum value of all items in {expr}.
 		items in {expr} cannot be used as a Number this results in
                 an error.  An empty |List| or |Dictionary| results in zero.
 
+		Can also be used as a |method|: >
+			mylist->max()
+
 menu_get({path}, {modes})				*menu_get()*
 		Returns a |List| of |Dictionaries| describing |menus| (defined
 		by |:menu|, |:amenu|, …), including |hidden-menus|.
@@ -6327,7 +6366,10 @@ min({expr})	Return the minimum value of all items in {expr}.
 		items in {expr} cannot be used as a Number this results in
 		an error.  An empty |List| or |Dictionary| results in zero.
 
-							*mkdir()* *E739*
+		Can also be used as a |method|: >
+			mylist->min()
+
+<							*mkdir()* *E739*
 mkdir({name} [, {path} [, {prot}]])
 		Create directory {name}.
 		If {path} is "p" then intermediate directories are created as
@@ -7085,6 +7127,10 @@ remove({list}, {idx} [, {end}])				*remove()*
 		Example: >
 			:echo "last item: " . remove(mylist, -1)
 			:call remove(mylist, 0, 9)
+
+<		Can also be used as a |method|: >
+			mylist->remove(idx)
+
 remove({dict}, {key})
 		Remove the entry from {dict} with key {key} and return it.
 		Example: >
@@ -7111,6 +7157,8 @@ repeat({expr}, {count})					*repeat()*
 			:let longlist = repeat(['a', 'b'], 3)
 <		Results in ['a', 'b', 'a', 'b', 'a', 'b'].
 
+		Can also be used as a |method|: >
+			mylist->repeat(count)
 
 resolve({filename})					*resolve()* *E655*
 		On MS-Windows, when {filename} is a shortcut (a .lnk file),
@@ -7130,6 +7178,8 @@ reverse({list})	Reverse the order of items in {list} in-place.  Returns
 		{list}.
 		If you want a list to remain unmodified make a copy first: >
 			:let revlist = reverse(copy(mylist))
+<		Can also be used as a |method|: >
+			mylist->reverse()
 
 round({expr})							*round()*
 		Round off {expr} to the nearest integral value and return it
@@ -8209,7 +8259,10 @@ sort({list} [, {func} [, {dict}]])			*sort()* *E702*
 		on numbers, text strings will sort next to each other, in the
 		same order as they were originally.
 
-		Also see |uniq()|.
+		Can also be used as a |method|: >
+			mylist->sort()
+
+<		Also see |uniq()|.
 
 		Example: >
 			func MyCompare(i1, i2)
@@ -8504,6 +8557,9 @@ string({expr})	Return {expr} converted to a String.  If {expr} is a Number,
 		method, use |msgpackdump()| or |json_encode()| if you need to
 		share data with other application.
 
+		Can also be used as a |method|: >
+			mylist->string()
+
 							*strlen()*
 strlen({expr})	The result is a Number, which is the length of the String
 		{expr} in bytes.
@@ -9149,6 +9205,9 @@ type({expr})							*type()*
 <               To check if the v:t_ variables exist use this: >
                         :if exists('v:t_number')
 
+<		Can also be used as a |method|: >
+			mylist->type()
+
 undofile({name})					*undofile()*
 		Return the name of the undo file that would be used for a file
 		with name {name} when writing.  This uses the 'undodir'
@@ -9211,10 +9270,15 @@ uniq({list} [, {func} [, {dict}]])			*uniq()* *E882*
 <		The default compare function uses the string representation of
 		each item.  For the use of {func} and {dict} see |sort()|.
 
+		Can also be used as a |method|: >
+			mylist->uniq()
+
 values({dict})						*values()*
 		Return a |List| with all the values of {dict}.  The |List| is
 		in arbitrary order.
 
+		Can also be used as a |method|: >
+			mydict->values()
 
 virtcol({expr})						*virtcol()*
 		The result is a Number, which is the screen column of the file

src/nvim/eval.c

@@ -3809,6 +3809,7 @@ static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string)
 //  + in front  unary plus (ignored)
 //  trailing []  subscript in String or List
 //  trailing .name entry in Dictionary
+//  trailing ->name()  method call
 //
 // "arg" must point to the first non-white of the expression.
 // "arg" is advanced to the next non-white after the recognized expression.
@@ -4080,6 +4081,63 @@ static int eval7(
   return ret;
 }
 
+/// Evaluate "->method()".
+/// @note "*arg" points to the '-'.
+/// @return FAIL or OK. "*arg" is advanced to after the ')'.
+static int eval_method(char_u **const arg, typval_T *const rettv,
+                       const bool evaluate, const bool verbose)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // Skip over the ->.
+  *arg += 2;
+
+  // Locate the method name.
+  const char_u *const name = *arg;
+  size_t len;
+  for (len = 0; ASCII_ISALNUM(name[len]) || name[len] == '_'; len++) {
+  }
+
+  if (len == 0) {
+    if (verbose) {
+      EMSG(_("E260: Missing name after ->"));
+    }
+    return FAIL;
+  }
+
+  // Check for the "(".  Skip over white space after it.
+  if (name[len] != '(') {
+    if (verbose) {
+      EMSG2(_(e_missingparen), name);
+    }
+    return FAIL;
+  }
+  *arg += len;
+
+  typval_T base = *rettv;
+  funcexe_T funcexe = FUNCEXE_INIT;
+  funcexe.evaluate = evaluate;
+  funcexe.basetv = &base;
+  rettv->v_type = VAR_UNKNOWN;
+  int ret = get_func_tv(name, len, rettv, arg, &funcexe);
+
+  // Clear the funcref afterwards, so that deleting it while
+  // evaluating the arguments is possible (see test55).
+  if (evaluate) {
+    tv_clear(&base);
+  }
+
+  // Stop the expression evaluation when immediately aborting on
+  // error, or when an interrupt occurred or an exception was thrown
+  // but not caught.
+  if (aborting()) {
+    if (ret == OK) {
+      tv_clear(rettv);
+    }
+    ret = FAIL;
+  }
+  return ret;
+}
+
 // TODO(ZyX-I): move to eval/expressions
 
 /*
@@ -8420,9 +8478,13 @@ int check_luafunc_name(const char *str, bool paren)
   }
 }
 
-/// Handle expr[expr], expr[expr:expr] subscript and .name lookup.
+/// Handle:
-/// Also handle function call with Funcref variable: func(expr)
+/// - expr[expr], expr[expr:expr] subscript
-/// Can all be combined: dict.func(expr)[idx]['func'](expr)
+/// - ".name" lookup
+/// - function call with Funcref variable: func(expr)
+/// - method call: var->method()
+///
+/// Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
 int
 handle_subscript(
     const char **const arg,
@@ -8456,12 +8518,11 @@ handle_subscript(
     }
   }
 
-
   while (ret == OK
-         && (**arg == '['
+         && (((**arg == '[' || (**arg == '.' && rettv->v_type == VAR_DICT)
-             || (**arg == '.' && rettv->v_type == VAR_DICT)
+               || (**arg == '(' && (!evaluate || tv_is_func(*rettv))))
-             || (**arg == '(' && (!evaluate || tv_is_func(*rettv))))
+              && !ascii_iswhite(*(*arg - 1)))
-         && !ascii_iswhite(*(*arg - 1))) {
+             || (**arg == '-' && (*arg)[1] == '>'))) {
     if (**arg == '(') {
       partial_T *pt = NULL;
       // need to copy the funcref so that we can clear rettv
@@ -8507,6 +8568,11 @@ handle_subscript(
       }
       tv_dict_unref(selfdict);
       selfdict = NULL;
+    } else if (**arg == '-') {
+      if (eval_method((char_u **)arg, rettv, evaluate, verbose) == FAIL) {
+        tv_clear(rettv);
+        ret = FAIL;
+      }
     } else {  // **arg == '[' || **arg == '.'
       tv_dict_unref(selfdict);
       if (rettv->v_type == VAR_DICT) {

src/nvim/eval.lua

@@ -5,6 +5,9 @@
 -- args  Number of arguments, list with maximum and minimum number of arguments
 --       or list with a minimum number of arguments only. Defaults to zero
 --       arguments.
+-- base  For methods: the argument to use as the base argument (1-indexed):
+--       base->method()
+--       Defaults to zero (function cannot be used as a method).
 -- func  Name of the C function which implements the VimL function. Defaults to
 --       `f_{funcname}`.
 
@@ -16,7 +19,7 @@ return {
   funcs={
     abs={args=1},
     acos={args=1, func="float_op_wrapper", data="&acos"},  -- WJMc
-    add={args=2},
+    add={args=2, base=1},
     ['and']={args=2},
     api_info={},
     append={args=2},
@@ -73,10 +76,10 @@ return {
     complete_check={},
     complete_info={args={0, 1}},
     confirm={args={1, 4}},
-    copy={args=1},
+    copy={args=1, base=1},
     cos={args=1, func="float_op_wrapper", data="&cos"},
     cosh={args=1, func="float_op_wrapper", data="&cosh"},
-    count={args={2, 4}},
+    count={args={2, 4}, base=1},
     cscope_connection={args={0, 3}},
     ctxget={args={0, 1}},
     ctxpop={},
@@ -93,7 +96,7 @@ return {
     did_filetype={},
     diff_filler={args=1},
     diff_hlID={args=2},
-    empty={args=1},
+    empty={args=1, base=1},
     environ={},
     escape={args=2},
     eval={args=1},
@@ -105,12 +108,12 @@ return {
     exp={args=1, func="float_op_wrapper", data="&exp"},
     expand={args={1, 3}},
     expandcmd={args=1},
-    extend={args={2, 3}},
+    extend={args={2, 3}, base=1},
     feedkeys={args={1, 2}},
     file_readable={args=1, func='f_filereadable'},  -- obsolete
     filereadable={args=1},
     filewritable={args=1},
-    filter={args=2},
+    filter={args=2, base=1},
     finddir={args={1, 3}},
     findfile={args={1, 3}},
     flatten={args={1, 2}},
@@ -128,7 +131,7 @@ return {
     funcref={args={1, 3}},
     ['function']={args={1, 3}},
     garbagecollect={args={0, 1}},
-    get={args={2, 3}},
+    get={args={2, 3}, base=1},
     getbufinfo={args={0, 1}},
     getbufline={args={2, 3}},
     getbufvar={args={2, 3}},
@@ -187,14 +190,14 @@ return {
     hostname={},
     iconv={args=3},
     indent={args=1},
-    index={args={2, 4}},
+    index={args={2, 4}, base=1},
     input={args={1, 3}},
     inputdialog={args={1, 3}},
     inputlist={args=1},
     inputrestore={},
     inputsave={},
     inputsecret={args={1, 2}},
-    insert={args={2, 3}},
+    insert={args={2, 3}, base=1},
     interrupt={args=0},
     invert={args=1},
     isdirectory={args=1},
@@ -202,7 +205,7 @@ return {
     islocked={args=1},
     isnan={args=1},
     id={args=1},
-    items={args=1},
+    items={args=1, base=1},
     jobclose={args={1, 2}, func="f_chanclose"},
     jobpid={args=1},
     jobresize={args=3},
@@ -210,12 +213,12 @@ return {
     jobstart={args={1, 2}},
     jobstop={args=1},
     jobwait={args={1, 2}},
-    join={args={1, 2}},
+    join={args={1, 2}, base=1},
     json_decode={args=1},
     json_encode={args=1},
-    keys={args=1},
+    keys={args=1, base=1},
     last_buffer_nr={},  -- obsolete
-    len={args=1},
+    len={args=1, base=1},
     libcall={args=3},
     libcallnr={args=3},
     line={args={1, 2}},
@@ -226,7 +229,7 @@ return {
     log={args=1, func="float_op_wrapper", data="&log"},
     log10={args=1, func="float_op_wrapper", data="&log10"},
     luaeval={args={1, 2}},
-    map={args=2},
+    map={args=2, base=1},
     maparg={args={1, 4}},
     mapcheck={args={1, 3}},
     match={args={2, 4}},
@@ -238,9 +241,9 @@ return {
     matchlist={args={2, 4}},
     matchstr={args={2, 4}},
     matchstrpos={args={2,4}},
-    max={args=1},
+    max={args=1, base=1},
     menu_get={args={1, 2}},
-    min={args=1},
+    min={args=1, base=1},
     mkdir={args={1, 3}},
     mode={args={0, 1}},
     msgpackdump={args=1},
@@ -270,11 +273,11 @@ return {
     reltime={args={0, 2}},
     reltimefloat={args=1},
     reltimestr={args=1},
-    remove={args={2, 3}},
+    remove={args={2, 3}, base=1},
     rename={args=2},
-    ['repeat']={args=2},
+    ['repeat']={args=2, base=1},
     resolve={args=1},
-    reverse={args=1},
+    reverse={args=1, base=1},
     round={args=1, func="float_op_wrapper", data="&round"},
     rpcnotify={args=varargs(2)},
     rpcrequest={args=varargs(2)},
@@ -327,7 +330,7 @@ return {
     sin={args=1, func="float_op_wrapper", data="&sin"},
     sinh={args=1, func="float_op_wrapper", data="&sinh"},
     sockconnect={args={2,3}},
-    sort={args={1, 3}},
+    sort={args={1, 3}, base=1},
     soundfold={args=1},
     stdioopen={args=1},
     spellbadword={args={0, 1}},
@@ -344,7 +347,7 @@ return {
     strftime={args={1, 2}},
     strgetchar={args={2, 2}},
     stridx={args={2, 3}},
-    string={args=1},
+    string={args=1, base=1},
     strlen={args=1},
     strpart={args={2, 4}},
     strptime={args=2},
@@ -383,11 +386,11 @@ return {
     tr={args=3},
     trim={args={1,3}},
     trunc={args=1, func="float_op_wrapper", data="&trunc"},
-    type={args=1},
+    type={args=1, base=1},
     undofile={args=1},
     undotree={},
-    uniq={args={1, 3}},
+    uniq={args={1, 3}, base=1},
-    values={args=1},
+    values={args=1, base=1},
     virtcol={args=1},
     visualmode={args={0, 1}},
     wait={args={2,3}},

src/nvim/eval/funcs.c

@@ -175,6 +175,50 @@ const VimLFuncDef *find_internal_func(const char *const name)
   return find_internal_func_gperf(name, len);
 }
 
+int call_internal_func(const char_u *const fname, const int argcount,
+                       typval_T *const argvars, typval_T *const rettv)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+  if (fdef == NULL) {
+    return ERROR_UNKNOWN;
+  } else if (argcount < fdef->min_argc) {
+    return ERROR_TOOFEW;
+  } else if (argcount > fdef->max_argc) {
+    return ERROR_TOOMANY;
+  }
+  argvars[argcount].v_type = VAR_UNKNOWN;
+  fdef->func(argvars, rettv, fdef->data);
+  return ERROR_NONE;
+}
+
+/// Invoke a method for base->method().
+int call_internal_method(const char_u *const fname, const int argcount,
+                         typval_T *const argvars, typval_T *const rettv,
+                         typval_T *const basetv)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+  if (fdef == NULL || fdef->base_arg == 0) {
+    return ERROR_UNKNOWN;
+  } else if (argcount + 1 < fdef->min_argc) {
+    return ERROR_TOOFEW;
+  } else if (argcount + 1 > fdef->max_argc) {
+    return ERROR_TOOMANY;
+  }
+
+  typval_T argv[MAX_FUNC_ARGS + 1];
+  const ptrdiff_t base_index = fdef->base_arg - 1;
+  memcpy(argv, argvars, base_index * sizeof(typval_T));
+  argv[base_index] = *basetv;
+  memcpy(argv + base_index + 1, argvars + base_index,
+         (argcount - base_index) * sizeof(typval_T));
+  argv[argcount + 1].v_type = VAR_UNKNOWN;
+
+  fdef->func(argv, rettv, fdef->data);
+  return ERROR_NONE;
+}
+
 /*
  * Return TRUE for a non-zero Number and a non-empty String.
  */

src/nvim/eval/funcs.h

@@ -14,6 +14,7 @@ typedef struct fst {
   char *name;        ///< Name of the function.
   uint8_t min_argc;  ///< Minimal number of arguments.
   uint8_t max_argc;  ///< Maximal number of arguments.
+  uint8_t base_arg;  ///< Method base arg # (1-indexed), or 0 if not a method.
   VimLFunc func;     ///< Function implementation.
   FunPtr data;       ///< Userdata for function implementation.
 } VimLFuncDef;

src/nvim/eval/userfunc.c

@@ -1514,7 +1514,10 @@ call_func(
       }
     } else if (fp != NULL || !builtin_function((const char *)rfname, -1)) {
       // User defined function.
-      if (fp == NULL) {
+      if (funcexe->basetv != NULL) {
+        // TODO(seandewar): support User function: base->Method()
+        fp = NULL;
+      } else if (fp == NULL) {
         fp = find_func(rfname);
       }
 
@@ -1560,20 +1563,13 @@ call_func(
           error = ERROR_NONE;
         }
       }
+    } else if (funcexe->basetv != NULL) {
+      // Find the method name in the table, call its implementation.
+      error = call_internal_method(fname, argcount, argvars, rettv,
+                                   funcexe->basetv);
     } else {
       // Find the function name in the table, call its implementation.
-      const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+      error = call_internal_func(fname, argcount, argvars, rettv);
-      if (fdef != NULL) {
-        if (argcount < fdef->min_argc) {
-          error = ERROR_TOOFEW;
-        } else if (argcount > fdef->max_argc) {
-          error = ERROR_TOOMANY;
-        } else {
-          argvars[argcount].v_type = VAR_UNKNOWN;
-          fdef->func(argvars, rettv, fdef->data);
-          error = ERROR_NONE;
-        }
-      }
     }
     /*
      * The function call (or "FuncUndefined" autocommand sequence) might
@@ -2937,7 +2933,7 @@ void ex_call(exarg_T *eap)
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this.
 
   if (*startarg != '(') {
-    EMSG2(_("E107: Missing parentheses: %s"), eap->arg);
+    EMSG2(_(e_missingparen), eap->arg);
     goto end;
   }
 

src/nvim/eval/userfunc.h

@@ -44,6 +44,7 @@ typedef struct {
   bool evaluate;       ///< actually evaluate expressions
   partial_T *partial;  ///< for extra arguments
   dict_T *selfdict;    ///< Dictionary for "self"
+  typval_T *basetv;    ///< base for base->method()
 } funcexe_T;
 
 #define FUNCEXE_INIT (funcexe_T) { \
@@ -54,6 +55,7 @@ typedef struct {
   .evaluate = false, \
   .partial = NULL, \
   .selfdict = NULL, \
+  .basetv = NULL, \
 }
 
 #define FUNCARG(fp, j)  ((char_u **)(fp->uf_args.ga_data))[j]

src/nvim/generators/gen_eval.lua

@@ -42,7 +42,7 @@ gperfpipe:write([[
 %language=ANSI-C
 %global-table
 %readonly-tables
-%define initializer-suffix ,0,0,NULL,NULL
+%define initializer-suffix ,0,0,0,NULL,NULL
 %define word-array-name functions
 %define hash-function-name hash_internal_func_gperf
 %define lookup-function-name find_internal_func_gperf
@@ -59,9 +59,10 @@ for name, def in pairs(funcs) do
   elseif #args == 1 then
     args[2] = 'MAX_FUNC_ARGS'
   end
+  local base = def.base or 0
   local func = def.func or ('f_' .. name)
   local data = def.data or "NULL"
-  gperfpipe:write(('%s,  %s, %s, &%s, (FunPtr)%s\n')
+  gperfpipe:write(('%s,  %s, %s, %s, &%s, (FunPtr)%s\n')
-                  :format(name, args[1], args[2], func, data))
+                  :format(name, args[1], args[2], base, func, data))
 end
 gperfpipe:close()

src/nvim/globals.h

@@ -972,6 +972,7 @@ EXTERN char_u e_write[] INIT(= N_("E80: Error while writing"));
 EXTERN char_u e_zerocount[] INIT(= N_("E939: Positive count required"));
 EXTERN char_u e_usingsid[] INIT(= N_(
     "E81: Using <SID> not in a script context"));
+EXTERN char_u e_missingparen[] INIT(= N_("E107: Missing parentheses: %s"));
 EXTERN char_u e_maxmempat[] INIT(= N_(
         "E363: pattern uses more memory than 'maxmempattern'"));
 EXTERN char_u e_emptybuf[] INIT(= N_("E749: empty buffer"));

src/nvim/testdir/test_method.vim

@@ -0,0 +1,68 @@
+" Tests for ->method()
+
+func Test_list()
+  let l = [1, 2, 3]
+  call assert_equal([1, 2, 3, 4], [1, 2, 3]->add(4))
+  call assert_equal(l, l->copy())
+  call assert_equal(1, l->count(2))
+  call assert_false(l->empty())
+  call assert_true([]->empty())
+  call assert_equal([1, 2, 3, 4, 5], [1, 2, 3]->extend([4, 5]))
+  call assert_equal([1, 3], [1, 2, 3]->filter('v:val != 2'))
+  call assert_equal(2, l->get(1))
+  call assert_equal(1, l->index(2))
+  call assert_equal([0, 1, 2, 3], [1, 2, 3]->insert(0))
+  call assert_fails('let x = l->items()', 'E715:')
+  call assert_equal('1 2 3', l->join())
+  call assert_fails('let x = l->keys()', 'E715:')
+  call assert_equal(3, l->len())
+  call assert_equal([2, 3, 4], [1, 2, 3]->map('v:val + 1'))
+  call assert_equal(3, l->max())
+  call assert_equal(1, l->min())
+  call assert_equal(2, [1, 2, 3]->remove(1))
+  call assert_equal([1, 2, 3, 1, 2, 3], l->repeat(2))
+  call assert_equal([3, 2, 1], [1, 2, 3]->reverse())
+  call assert_equal([1, 2, 3, 4], [4, 2, 3, 1]->sort())
+  call assert_equal('[1, 2, 3]', l->string())
+  call assert_equal(v:t_list, l->type())
+  call assert_equal([1, 2, 3], [1, 1, 2, 3, 3]->uniq())
+  call assert_fails('let x = l->values()', 'E715:')
+endfunc
+
+func Test_dict()
+  let d = #{one: 1, two: 2, three: 3}
+
+  call assert_equal(d, d->copy())
+  call assert_equal(1, d->count(2))
+  call assert_false(d->empty())
+  call assert_true({}->empty())
+  call assert_equal(#{one: 1, two: 2, three: 3, four: 4}, d->extend(#{four: 4}))
+  call assert_equal(#{one: 1, two: 2, three: 3}, d->filter('v:val != 4'))
+  call assert_equal(2, d->get('two'))
+  " Nvim doesn't support Blobs yet; expect a different emsg
+  " call assert_fails("let x = d->index(2)", 'E897:')
+  " call assert_fails("let x = d->insert(0)", 'E899:')
+  call assert_fails("let x = d->index(2)", 'E714:')
+  call assert_fails("let x = d->insert(0)", 'E686:')
+  call assert_equal([['one', 1], ['two', 2], ['three', 3]], d->items())
+  call assert_fails("let x = d->join()", 'E714:')
+  call assert_equal(['one', 'two', 'three'], d->keys())
+  call assert_equal(3, d->len())
+  call assert_equal(#{one: 2, two: 3, three: 4}, d->map('v:val + 1'))
+  call assert_equal(#{one: 1, two: 2, three: 3}, d->map('v:val - 1'))
+  call assert_equal(3, d->max())
+  call assert_equal(1, d->min())
+  call assert_equal(2, d->remove("two"))
+  let d.two = 2
+  call assert_fails('let x = d->repeat(2)', 'E731:')
+  " Nvim doesn't support Blobs yet; expect a different emsg
+  " call assert_fails('let x = d->reverse()', 'E899:')
+  call assert_fails('let x = d->reverse()', 'E686:')
+  call assert_fails('let x = d->sort()', 'E686:')
+  call assert_equal("{'one': 1, 'two': 2, 'three': 3}", d->string())
+  call assert_equal(v:t_dict, d->type())
+  call assert_fails('let x = d->uniq()', 'E686:')
+  call assert_equal([1, 2, 3], d->values())
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab