Close #2285 - Add a function for use with omnifunc

README.md

@@ -168,6 +168,13 @@ other plugins, and can be enabled by changing a setting before ALE is loaded.
 let g:ale_completion_enabled = 1
 ```
 
+ALE provides an omni-completion function you can use for triggering
+completion manually with `<C-x><C-o>`.
+
+```vim
+set omnifunc=ale#completion#OmniFunc
+```
+
 See `:help ale-completion` for more information.
 
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