fallback to toggle-line-comment and vice versa if needed

data/core/commands/doc.lua

@@ -293,8 +293,13 @@ local commands = {
   end,
 
   ["doc:toggle-block-comments"] = function()
-    local comment = doc().syntax.multiline_comment
-    if not comment then return end
+    local comment = doc().syntax.block_comment
+    if not comment then
+      if doc().syntax.comment then
+        command.perform "doc:toggle-line-comments"
+      end
+      return
+    end
 
     for idx, line1, col1, line2, col2 in doc_multiline_selections(true) do
       local text = doc():get_text(line1, col1, line2, col2)
@@ -342,7 +347,12 @@ local commands = {
 
   ["doc:toggle-line-comments"] = function()
     local comment = doc().syntax.comment
-    if not comment then return end
+    if not comment then
+      if doc().syntax.block_comment then
+        command.perform "doc:toggle-block-comments"
+      end
+      return
+    end
     local indentation = doc():get_indent_string()
     local comment_text = comment .. " "
     for idx, line1, _, line2 in doc_multiline_selections(true) do

data/plugins/language_c.lua

@@ -5,7 +5,7 @@ syntax.add {
   name = "C",
   files = { "%.c$", "%.h$", "%.inl$" },
   comment = "//",
-  multiline_comment = { "/*", "*/" },
+  block_comment = { "/*", "*/" },
   patterns = {
     { pattern = "//.-\n",                type = "comment" },
     { pattern = { "/%*", "%*/" },        type = "comment" },

data/plugins/language_cpp.lua

@@ -10,7 +10,7 @@ syntax.add {
     "%.c++$", "%.hh$", "%.H$", "%.hxx$", "%.hpp$", "%.h++$"
   },
   comment = "//",
-  multiline_comment = { "/*", "*/" },
+  block_comment = { "/*", "*/" },
   patterns = {
     { pattern = "//.-\n",                   type = "comment" },
     { pattern = { "/%*", "%*/" },           type = "comment" },

data/plugins/language_css.lua

@@ -4,7 +4,7 @@ local syntax = require "core.syntax"
 syntax.add {
   name = "CSS",
   files = { "%.css$" },
-  multiline_comment = { "/*", "*/" },
+  block_comment = { "/*", "*/" },
   patterns = {
     { pattern = "\\.",                type = "normal"   },
     { pattern = "//.-\n",             type = "comment"  },

data/plugins/language_html.lua

@@ -4,7 +4,7 @@ local syntax = require "core.syntax"
 syntax.add {
   name = "HTML",
   files = { "%.html?$" },
-  multiline_comment = { "<!--", "-->" },
+  block_comment = { "<!--", "-->" },
   patterns = {
     {
       pattern = {

data/plugins/language_js.lua

@@ -5,7 +5,7 @@ syntax.add {
   name = "JavaScript",
   files = { "%.js$", "%.json$", "%.cson$" },
   comment = "//",
-  multiline_comment = { "/*", "*/" },
+  block_comment = { "/*", "*/" },
   patterns = {
     { pattern = "//.-\n",               type = "comment"  },
     { pattern = { "/%*", "%*/" },       type = "comment"  },

data/plugins/language_lua.lua

@@ -6,7 +6,7 @@ syntax.add {
   files = "%.lua$",
   headers = "^#!.*[ /]lua",
   comment = "--",
-  multiline_comment = { "--[[", "]]" },
+  block_comment = { "--[[", "]]" },
   patterns = {
     { pattern = { '"', '"', '\\' },          type = "string" },
     { pattern = { "'", "'", '\\' },          type = "string" },

data/plugins/language_xml.lua

@@ -5,7 +5,7 @@ syntax.add {
   name = "XML",
   files = { "%.xml$" },
   headers = "<%?xml",
-  multiline_comment = { "<!--", "-->" },
+  block_comment = { "<!--", "-->" },
   patterns = {
     { pattern = { "<!%-%-", "%-%->" },     type = "comment"  },
     { pattern = { '%f[^>][^<]', '%f[<]' }, type = "normal"   },