feat(api): support abbreviations in nvim_set_keymap

closes #19198

runtime/doc/api.txt

@@ -1486,7 +1486,9 @@ nvim_set_keymap({mode}, {lhs}, {rhs}, {*opts})             *nvim_set_keymap()*
 
     Parameters: ~
       • {mode}  Mode short-name (map command prefix: "n", "i", "v", "x", …) or
-                "!" for |:map!|, or empty string for |:map|.
+                "!" for |:map!|, or empty string for |:map|. "ia", "ca" or
+                "!a" for abbreviation in insert mode, cmdline mode, or both,
+                respectively
       • {lhs}   Left-hand-side |{lhs}| of the mapping.
       • {rhs}   Right-hand-side |{rhs}| of the mapping.
       • {opts}  Optional parameters map: Accepts all |:map-arguments| as keys

runtime/doc/news.txt

@@ -82,6 +82,8 @@ The following new APIs or features were added.
 
 • |vim.system()| for running system commands.
 
+• |nvim_set_keymap()| now supports abbreviations.
+
 ==============================================================================
 CHANGED FEATURES                                                 *news-changed*
 

src/nvim/api/vim.c

@@ -1420,6 +1420,7 @@ ArrayOf(Dictionary) nvim_get_keymap(String mode)
 /// @param channel_id
 /// @param  mode  Mode short-name (map command prefix: "n", "i", "v", "x", …)
 ///               or "!" for |:map!|, or empty string for |:map|.
+///               "ia", "ca" or "!a" for abbreviation in insert mode, cmdline mode, or both, respectively
 /// @param  lhs   Left-hand-side |{lhs}| of the mapping.
 /// @param  rhs   Right-hand-side |{rhs}| of the mapping.
 /// @param  opts  Optional parameters map: Accepts all |:map-arguments| as keys except |<buffer>|,

src/nvim/mapping.c

@@ -2603,13 +2603,21 @@ void modify_keymap(uint64_t channel_id, Buffer buffer, bool is_unmap, String mod
     goto fail_and_free;
   }
 
-  if (mode.size > 1) {
+  bool is_abbrev = false;
+  if (mode.size > 2) {
     api_set_error(err, kErrorTypeValidation, "Shortname is too long: %s", mode.data);
     goto fail_and_free;
+  } else if (mode.size == 2) {
+    if ((mode.data[0] != '!' && mode.data[0] != 'i' && mode.data[0] != 'c')
+        || mode.data[1] != 'a') {
+      api_set_error(err, kErrorTypeValidation, "Shortname is too long: %s", mode.data);
+      goto fail_and_free;
+    }
+    is_abbrev = true;
   }
   int mode_val;  // integer value of the mapping mode, to be passed to do_map()
   char *p = (mode.size) ? mode.data : "m";
-  if (strncmp(p, "!", 2) == 0) {
+  if (*p == '!') {
     mode_val = get_map_mode(&p, true);  // mapmode-ic
   } else {
     mode_val = get_map_mode(&p, false);
@@ -2654,7 +2662,7 @@ void modify_keymap(uint64_t channel_id, Buffer buffer, bool is_unmap, String mod
     maptype_val = MAPTYPE_NOREMAP;
   }
 
-  switch (buf_do_map(maptype_val, &parsed_args, mode_val, 0, target_buf)) {
+  switch (buf_do_map(maptype_val, &parsed_args, mode_val, is_abbrev, target_buf)) {
   case 0:
     break;
   case 1:

test/functional/api/keymap_spec.lua

@@ -988,6 +988,54 @@ describe('nvim_set_keymap, nvim_del_keymap', function()
     eq("\nn  lhs           rhs\n                 map description",
        helpers.exec_capture("nmap lhs"))
   end)
+
+  it('can define !-mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('!a', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The 1 and the bar and the 2 again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The 3 is the one', meths.eval'x')
+  end)
+
+  it('can define insert mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('ia', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The 1 and the bar and the 2 again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The foo is the one', meths.eval'x')
+  end)
+
+  it('can define cmdline mode abbreviations with lua callbacks', function()
+    exec_lua [[
+      GlobalCount = 0
+      vim.api.nvim_set_keymap('ca', 'foo', '', {expr = true, callback = function()
+        GlobalCount = GlobalCount + 1
+        return tostring(GlobalCount)
+      end})
+    ]]
+
+    feed 'iThe foo and the bar and the foo again<esc>'
+    eq('The foo and the bar and the foo again', meths.get_current_line())
+
+    feed ':let x = "The foo is the one"<cr>'
+    eq('The 1 is the one', meths.eval'x')
+  end)
 end)
 
 describe('nvim_buf_set_keymap, nvim_buf_del_keymap', function()