Add support with Go language.

sources_non_forked/vim-go/autoload/go/implements.vim

@@ -0,0 +1,44 @@
+" don't spam the user when Vim is started in Vi compatibility mode
+let s:cpo_save = &cpo
+set cpo&vim
+
+function! go#implements#Implements(selected) abort
+  let l:mode = go#config#ImplementsMode()
+  if l:mode == 'guru'
+		call go#guru#Implements(a:selected)
+    return
+  elseif l:mode == 'gopls'
+    if !go#config#GoplsEnabled()
+      call go#util#EchoError("go_implements_mode is 'gopls', but gopls is disabled")
+    endif
+    let [l:line, l:col] = getpos('.')[1:2]
+    let [l:line, l:col] = go#lsp#lsp#Position(l:line, l:col)
+    let l:fname = expand('%:p')
+    call go#lsp#Implements(l:fname, l:line, l:col, funcref('s:parse_output'))
+    return
+  else
+    call go#util#EchoWarning('unknown value for g:go_implements_mode')
+  endif
+endfunction
+
+" This uses Vim's errorformat to parse the output and put it into a quickfix
+" or locationlist.
+function! s:parse_output(exit_val, output, title) abort
+  if a:exit_val
+    call go#util#EchoError(a:output)
+    return
+  endif
+
+  let errformat = ",%f:%l:%c:\ %m"
+  let l:listtype = go#list#Type("GoImplements")
+  call go#list#ParseFormat(l:listtype, errformat, a:output, a:title, 0)
+
+  let errors = go#list#Get(l:listtype)
+  call go#list#Window(l:listtype, len(errors))
+endfunction
+
+" restore Vi compatibility settings
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+" vim: sw=2 ts=2 et