ext_cmdline: Add function block support

src/nvim/api/ui_events.in.h

@@ -75,5 +75,9 @@ void cmdline_char(String c, Integer shift, Integer level)
     FUNC_API_SINCE(3) FUNC_API_REMOTE_ONLY;
 void cmdline_hide(Integer level)
     FUNC_API_SINCE(3) FUNC_API_REMOTE_ONLY;
+void cmdline_function_show(void)
+    FUNC_API_SINCE(3) FUNC_API_REMOTE_ONLY;
+void cmdline_function_hide(void)
+    FUNC_API_SINCE(3) FUNC_API_REMOTE_ONLY;
 
 #endif  // NVIM_API_UI_EVENTS_IN_H

src/nvim/eval.c

@@ -19816,6 +19816,10 @@ void ex_function(exarg_T *eap)
     goto errret_2;
   }
 
+  if (ui_is_external(kUICmdline)) {
+    ui_call_cmdline_function_show();
+  }
+
   // find extra arguments "range", "dict", "abort" and "closure"
   for (;; ) {
     p = skipwhite(p);
@@ -19868,7 +19872,9 @@ void ex_function(exarg_T *eap)
     if (!eap->skip && did_emsg)
       goto erret;
 
-    msg_putchar('\n');              /* don't overwrite the function name */
+    if (!ui_is_external(kUICmdline)) {
+      msg_putchar('\n');              /* don't overwrite the function name */
+    }
     cmdline_row = msg_row;
   }
 
@@ -20194,6 +20200,9 @@ ret_free:
   xfree(name);
   did_emsg |= saved_did_emsg;
   need_wait_return |= saved_wait_return;
+  if (ui_is_external(kUICmdline)) {
+    ui_call_cmdline_function_hide();
+  }
 }
 
 /// Get a function name, translating "<SID>" and "<SNR>".

test/functional/ui/cmdline_spec.lua

@@ -7,7 +7,7 @@ if helpers.pending_win32(pending) then return end
 describe('External command line completion', function()
   local screen
   local shown = false
-  local firstc, prompt, content, pos, char, shift, level, current_hide_level
+  local firstc, prompt, content, pos, char, shift, level, current_hide_level, in_function
 
   before_each(function()
     clear()
@@ -24,6 +24,10 @@ describe('External command line completion', function()
         char, shift = unpack(data)
       elseif name == "cmdline_pos" then
         pos = data[1]
+      elseif name == "cmdline_function_show" then
+        in_function = true
+      elseif name == "cmdline_function_hide" then
+        in_function = false
       end
     end)
   end)
@@ -158,6 +162,39 @@ describe('External command line completion', function()
         eq(1, current_hide_level)
       end)
 
+      feed(':function Foo()<cr>')
+      screen:expect([[
+        ^                         |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], nil, nil, function()
+        eq(true, in_function)
+      end)
+
+      feed('line1<cr>')
+      screen:expect([[
+        ^                         |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], nil, nil, function()
+        eq(true, in_function)
+      end)
+
+      feed('endfunction<cr>')
+      screen:expect([[
+        ^                         |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], nil, nil, function()
+        eq(false, in_function)
+      end)
+
     end)
   end)
 end)