API: nvim_call_dict_function: eliminate internal param

The `internal` param is difficult to explain, and will rarely be
anything but `true`.  To avoid it, use a hack: check if the resolved
dict value starts with "function(".

src/nvim/api/vim.c

@@ -317,7 +317,7 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
   Object rv = OBJECT_INIT;
   if (args.size > MAX_FUNC_ARGS) {
     api_set_error(err, kErrorTypeValidation,
-                  "Function called with too many arguments.");
+                  "Function called with too many arguments");
     return rv;
   }
 
@@ -338,7 +338,7 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
                     vim_args, NULL, curwin->w_cursor.lnum,
                     curwin->w_cursor.lnum, &dummy, true, NULL, self);
   if (r == FAIL) {
-    api_set_error(err, kErrorTypeException, "Error calling function.");
+    api_set_error(err, kErrorTypeException, "Error calling function");
   }
   if (!try_end(err)) {
     rv = vim_to_object(&rettv);
@@ -371,12 +371,10 @@ Object nvim_call_function(String fn, Array args, Error *err)
 ///
 /// @param dict Dictionary, or String evaluating to a VimL |self| dict
 /// @param fn Function to call
-/// @param internal true if the function is stored on the dict
 /// @param args Functions arguments packed in an Array
 /// @param[out] err Error details, if any
 /// @return Result of the function call
-Object nvim_call_dict_function(Object dict, String fn, Boolean internal,
+Object nvim_call_dict_function(Object dict, String fn, Array args, Error *err)
-                               Array args, Error *err)
   FUNC_API_SINCE(4)
 {
   Object rv = OBJECT_INIT;
@@ -399,13 +397,8 @@ Object nvim_call_dict_function(Object dict, String fn, Boolean internal,
       break;
     }
     case kObjectTypeDictionary: {
-      if (internal) {
+      if (!object_to_vim(dict, &rettv, err)) {
-        api_set_error(err, kErrorTypeValidation,
+        goto end;
-                      "Cannot invoke RPC dict as a VimL reference");
-        return rv;
-      } else if (!object_to_vim(dict, &rettv, err)) {
-        tv_clear(&rettv);
-        return rv;
       }
       break;
     }
@@ -421,22 +414,25 @@ Object nvim_call_dict_function(Object dict, String fn, Boolean internal,
     goto end;
   }
 
-  if (internal) {
+  if (dict.type != kObjectTypeDictionary) {
     dictitem_T *const di = tv_dict_find(self_dict, fn.data, (ptrdiff_t)fn.size);
-    if (di == NULL) {
+    if (di != NULL) {
-      api_set_error(err, kErrorTypeValidation, "Function not found in dict");
+      if (di->di_tv.v_type != VAR_STRING) {
-      goto end;
+        api_set_error(err, kErrorTypeValidation,
+                      "Value found in dict is not a valid function");
+        goto end;
+      }
+      // XXX: Hack to guess if function is "internal".
+      bool internal = (0 != STRNCMP(di->di_tv.vval.v_string, "function(", 9));
+      if (internal) {
+        fn = (String) {
+          .data = (char *)di->di_tv.vval.v_string,
+          .size = strlen((char *)di->di_tv.vval.v_string),
+        };
+      }
     }
-    if (di->di_tv.v_type != VAR_STRING) {
-      api_set_error(err, kErrorTypeValidation,
-                    "Value found in dict is not a valid function");
-      goto end;
-    }
-    fn = (String) {
-      .data = (char *)di->di_tv.vval.v_string,
-      .size = strlen((char *)di->di_tv.vval.v_string),
-    };
   }
+
   if (!fn.data || fn.size < 1) {
     api_set_error(err, kErrorTypeValidation, "Invalid (empty) function name");
     goto end;

test/functional/api/vim_spec.lua

@@ -180,37 +180,45 @@ describe('api', function()
   end)
 
   describe('nvim_call_dict_function', function()
-    it('invokes VimL dict', function()
+    it('invokes VimL dict function', function()
-      source('function! F(name) dict\n  return self.greeting . ", " . a:name . "!"\nendfunction')
+      source([[
+        function! F(name) dict
+          return self.greeting . ", " . a:name . "!"
+        endfunction
+      ]])
+
+      -- function() ("non-internal") function
       nvim('set_var', 'dict_function_dict', { greeting = 'Hello', F = 'function("F")' })
-      eq('Hello, World!', nvim('call_dict_function', 'g:dict_function_dict', 'F', false, {'World'}))
+      eq('Hello, World!', nvim('call_dict_function', 'g:dict_function_dict', 'F', {'World'}))
       eq({ greeting = 'Hello', F = 'function("F")' }, nvim('get_var', 'dict_function_dict'))
+
+      -- "internal" function
       nvim('set_var', 'dict_function_dict_i', { greeting = 'Hi', F = "F" })
-      eq('Hi, Moon!', nvim('call_dict_function', 'g:dict_function_dict_i', 'F', true, {'Moon'}))
+      eq('Hi, Moon!', nvim('call_dict_function', 'g:dict_function_dict_i', 'F', {'Moon'}))
       eq({ greeting = 'Hi', F = "F" }, nvim('get_var', 'dict_function_dict_i'))
     end)
     it('invokes RPC dict', function()
       source('function! G() dict\n  return self.result\nendfunction')
-      eq('self', nvim('call_dict_function', { result = 'self', G = 'G'}, 'G', false, {}))
+      eq('it works', nvim('call_dict_function', { result = 'it works', G = 'G'}, 'G', {}))
     end)
     it('validates args', function()
       command('let g:d={"baz":"zub","meep":[]}')
-      expect_err('Function not found in dict', request,
+      expect_err('Error calling function', request,
-                 'nvim_call_dict_function', 'g:d', 'bogus', true, {1,2})
+                 'nvim_call_dict_function', 'g:d', 'bogus', {1,2})
-      expect_err('Error calling function.', request,
+      expect_err('Error calling function', request,
-                 'nvim_call_dict_function', 'g:d', 'baz', true, {1,2})
+                 'nvim_call_dict_function', 'g:d', 'baz', {1,2})
       expect_err('Value found in dict is not a valid function', request,
-                 'nvim_call_dict_function', 'g:d', 'meep', true, {1,2})
+                 'nvim_call_dict_function', 'g:d', 'meep', {1,2})
-      expect_err('Cannot invoke RPC dict as a VimL reference', request,
+      expect_err('Error calling function', request,
-                 'nvim_call_dict_function', { f = '' }, 'f', true, {1,2})
+                 'nvim_call_dict_function', { f = '' }, 'f', {1,2})
       expect_err('Invalid %(empty%) function name', request,
-                 'nvim_call_dict_function', "{ 'f': '' }", 'f', true, {1,2})
+                 'nvim_call_dict_function', "{ 'f': '' }", 'f', {1,2})
       expect_err('dict argument type must be String or Dictionary', request,
-                 'nvim_call_dict_function', 42, 'f', true, {1,2})
+                 'nvim_call_dict_function', 42, 'f', {1,2})
       expect_err('Failed to evaluate dict expression', request,
-                 'nvim_call_dict_function', 'foo', 'f', true, {1,2})
+                 'nvim_call_dict_function', 'foo', 'f', {1,2})
       expect_err('Referenced dict does not exist', request,
-                 'nvim_call_dict_function', '42', 'f', true, {1,2})
+                 'nvim_call_dict_function', '42', 'f', {1,2})
     end)
   end)