Configure Tabbar to show arity and also separate OTP functions

Author: Gaspar Chilingarov

plugin/vim-ide-elixir.vim

@@ -1,4 +1,4 @@
-" 
+"
 " vim: et ts=2 sts=2 sw=2
 "
 
@@ -21,22 +21,93 @@ let s:bundle_path = s:path."/bundle"
 "  "runtime(s:bundle_path)
 "endif
 
+
+function! Tag_transform(tags)
+  " remove OTP callbacks from ordinary function list
+  call filter(a:tags, ' !(v:val.fields.kind == "f" && v:val.name =~ "\\v(handle_call|handle_info|handle_cast|init|terminate)") ')
+
+  function! Arity_extract(idx, tag)
+    if a:tag.fields.kind == 'f' || a:tag.fields.kind == 'g'
+      let args_string = substitute(a:tag.pattern, "^.*".a:tag.name."[ \t]*", "", "")
+      let args_string = substitute(args_string, "do[ \t]*\\\\[$]$", "", "")
+      let args_string = substitute(args_string, "[ \t]*", "", "g")
+
+      let args_len = len(args_string)
+
+      if args_len == 0
+        let a:tag.name = a:tag.name."/0"
+      else
+        let old_args_len = -10000
+        while args_len != old_args_len
+          let args_string = substitute(args_string, "{[^}]*}", "", "g")
+          let args_string = substitute(args_string, "\\[[^]]*\\]", "", "g")
+          let old_args_len = args_len
+          let args_len = len(args_string)
+          echo(args_string)
+        endwhile
+
+        let comma_count = len(substitute(args_string, "[^,]", "", "g"))
+        let a:tag.name = a:tag.name . "/" . (comma_count + 1)
+      endif
+
+      return a:tag
+    else
+      return a:tag
+    endif
+  endfunction
+
+  " replaces function names with function_name/arity notation
+  call map(a:tags, function('Arity_extract'))
+
+  let seen_list = map(copy(a:tags), '[v:val.fields.kind, v:val.name, v:val.fields.line]')
+
+  let seen_fnames = {}
+  for [kind, fname, line] in seen_list
+    if ! has_key(seen_fnames, kind.fname)
+      let seen_fnames[kind.fname] = line
+    endif
+  endfor
+
+  " leaves only first definition of function with same arity
+  function! Filter_fun(seen_hash, idx, tag)
+    let key = a:tag.fields.kind . a:tag.name
+    let line = a:tag.fields.line
+
+    return a:seen_hash[key] == line
+  endfunction
+
+  call filter(a:tags, function('Filter_fun', [seen_fnames]))
+
+  return a:tags
+endfunction
+
+
 let g:tagbar_type_elixir = {
     \ 'ctagstype' : 'elixir',
     \ 'deffile' : s:path . '/extras/elixir-ctags/.ctags',
+    \ 'transform': function("Tag_transform"),
     \ 'kinds' : [
-        \ 'f:functions',
-        \ 'functions:functions',
+        \ 'm:modules',
+        \ 'O:OTP callbacks',
+        \ 't:tests',
+        \ 'f:functions (public)',
+        \ 'g:functions (private)',
         \ 'c:callbacks',
         \ 'd:delegates',
         \ 'e:exceptions',
         \ 'i:implementations',
         \ 'a:macros',
         \ 'o:operators',
-        \ 'm:modules',
+        \ 's:structs',
         \ 'p:protocols',
-        \ 'r:records'
+        \ 'r:records',
+        \ 'T:types',
+        \ 'z:foo'
     \ ]
 \ }
 
 set updatetime=500
+
+" keyboard shortcuts
+nmap <F4> :TagbarToggle<CR>
+