--- a/runtime/indent/javascript.vim
+++ b/runtime/indent/javascript.vim
@@ -2,7 +2,7 @@
 " Language: Javascript
 " Maintainer: Chris Paul ( https://github.com/bounceme )
 " URL: https://github.com/pangloss/vim-javascript
-" Last Change: August 25, 2016
+" Last Change: December 31, 2016
 
 " Only load this indent file when no other was loaded.
 if exists('b:did_indent')
@@ -12,11 +12,10 @@ let b:did_indent = 1
 
 " Now, set up our indentation expression and keys that trigger it.
 setlocal indentexpr=GetJavascriptIndent()
-setlocal nolisp noautoindent nosmartindent
-setlocal indentkeys=0{,0},0),0],:,!^F,o,O,e
-setlocal cinoptions+=j1,J1
+setlocal autoindent nolisp nosmartindent
+setlocal indentkeys+=0],0)
 
-let b:undo_indent = 'setlocal indentexpr< smartindent< autoindent< indentkeys< cinoptions<'
+let b:undo_indent = 'setlocal indentexpr< smartindent< autoindent< indentkeys<'
 
 " Only define the function once.
 if exists('*GetJavascriptIndent')
@@ -37,158 +36,329 @@ else
   endfunction
 endif
 
-let s:line_pre = '^\s*\%(\%(\%(\/\*.\{-}\)\=\*\+\/\s*\)\=\)\@>'
-let s:expr_case = s:line_pre . '\%(\%(case\>.\+\)\|default\)\s*:'
-" Regex of syntax group names that are or delimit string or are comments.
-let s:syng_strcom = '\%(s\%(tring\|pecial\)\|comment\|regex\|doc\|template\)'
-
-" Regex of syntax group names that are strings or documentation.
-let s:syng_comment = '\%(comment\|doc\)'
-
-" Expression used to check whether we should skip a match with searchpair().
-let s:skip_expr = "synIDattr(synID(line('.'),col('.'),0),'name') =~? '".s:syng_strcom."'"
-
+" searchpair() wrapper
 if has('reltime')
-  function s:GetPair(start,end,flags,time)
-    return searchpair(a:start,'',a:end,a:flags,s:skip_expr,max([prevnonblank(v:lnum) - 2000,0]),a:time)
+  function s:GetPair(start,end,flags,skip,time,...)
+    return searchpair('\m'.a:start,'','\m'.a:end,a:flags,a:skip,max([prevnonblank(v:lnum) - 2000,0] + a:000),a:time)
   endfunction
 else
-  function s:GetPair(start,end,flags,n)
-    return searchpair(a:start,'',a:end,a:flags,0,max([prevnonblank(v:lnum) - 2000,0]))
+  function s:GetPair(start,end,flags,skip,...)
+    return searchpair('\m'.a:start,'','\m'.a:end,a:flags,a:skip,max([prevnonblank(v:lnum) - 1000,get(a:000,1)]))
   endfunction
 endif
 
-let s:line_term = '\s*\%(\%(\/\%(\%(\*.\{-}\*\/\)\|\%(\*\+\)\)\)\s*\)\=$'
+" Regex of syntax group names that are or delimit string or are comments.
+let s:syng_strcom = 'string\|comment\|regex\|special\|doc\|template'
+let s:syng_str = 'string\|template'
+let s:syng_com = 'comment\|doc'
+" Expression used to check whether we should skip a match with searchpair().
+let s:skip_expr = "synIDattr(synID(line('.'),col('.'),0),'name') =~? '".s:syng_strcom."'"
+
+function s:skip_func()
+  if !s:free || search('\m`\|\*\/','nW',s:looksyn)
+    let s:free = !eval(s:skip_expr)
+    let s:looksyn = s:free ? line('.') : s:looksyn
+    return !s:free
+  endif
+  let s:looksyn = line('.')
+  return (search('\m\/','nbW',s:looksyn) || search('\m[''"]\|\\$','nW',s:looksyn)) && eval(s:skip_expr)
+endfunction
+
+function s:alternatePair(stop)
+  let pos = getpos('.')[1:2]
+  while search('\m[][(){}]','bW',a:stop)
+    if !s:skip_func()
+      let idx = stridx('])}',s:looking_at())
+      if idx + 1
+        if !s:GetPair(['\[','(','{'][idx], '])}'[idx],'bW','s:skip_func()',2000,a:stop)
+          break
+        endif
+      else
+        return
+      endif
+    endif
+  endwhile
+  call call('cursor',pos)
+endfunction
+
+function s:save_pos(f,...)
+  let l:pos = getpos('.')[1:2]
+  let ret = call(a:f,a:000)
+  call call('cursor',l:pos)
+  return ret
+endfunction
+
+function s:syn_at(l,c)
+  return synIDattr(synID(a:l,a:c,0),'name')
+endfunction
+
+function s:looking_at()
+  return getline('.')[col('.')-1]
+endfunction
+
+function s:token()
+  return s:looking_at() =~ '\k' ? expand('<cword>') : s:looking_at()
+endfunction
+
+function s:b_token()
+  if s:looking_at() =~ '\k'
+    call search('\m\<','cbW')
+  endif
+  return search('\m\S','bW')
+endfunction
+
+function s:previous_token()
+  let l:n = line('.')
+  while s:b_token()
+    if (s:looking_at() == '/' || line('.') != l:n && search('\m\/\/','nbW',
+          \ line('.'))) && s:syn_at(line('.'),col('.')) =~? s:syng_com
+      call search('\m\_[^/]\zs\/[/*]','bW')
+    else
+      return s:token()
+    endif
+  endwhile
+  return ''
+endfunction
+
+function s:others(p)
+  return "((line2byte(line('.')) + col('.')) <= ".(line2byte(a:p[0]) + a:p[1]).") || ".s:skip_expr
+endfunction
+
+function s:tern_skip(p)
+  return s:GetPair('{','}','nbW',s:others(a:p),200,a:p[0]) > 0
+endfunction
+
+function s:tern_col(p)
+  return s:GetPair('?',':\@<!::\@!','nbW',s:others(a:p)
+        \ .' || s:tern_skip('.string(a:p).')',200,a:p[0]) > 0
+endfunction
+
+function s:label_col()
+  let pos = getpos('.')[1:2]
+  let [s:looksyn,s:free] = pos
+  call s:alternatePair(0)
+  if s:save_pos('s:IsBlock')
+    let poss = getpos('.')[1:2]
+    return call('cursor',pos) || !s:tern_col(poss)
+  elseif s:looking_at() == ':'
+    return !s:tern_col([0,0])
+  endif
+endfunction
 
 " configurable regexes that define continuation lines, not including (, {, or [.
-if !exists('g:javascript_opfirst')
-  let g:javascript_opfirst = '\%([<>,:?^%|*&]\|\/[^/*]\|\([-.+]\)\1\@!\|=>\@!\|in\%(stanceof\)\=\>\)'
-endif
-if !exists('g:javascript_continuation')
-  let g:javascript_continuation = '\%([<=,.?/*:^%|&]\|+\@<!+\|-\@<!-\|=\@<!>\|\<in\%(stanceof\)\=\)'
-endif
+let s:opfirst = '^' . get(g:,'javascript_opfirst',
+      \ '\%([<>=,?^%|*/&]\|\([-.:+]\)\1\@!\|!=\|in\%(stanceof\)\=\>\)')
+let s:continuation = get(g:,'javascript_continuation',
+      \ '\%([<=,.~!?/*^%|&:]\|+\@<!+\|-\@<!-\|=\@<!>\|\<\%(typeof\|delete\|void\|in\|instanceof\)\)') . '$'
 
-let g:javascript_opfirst = s:line_pre . g:javascript_opfirst
-let g:javascript_continuation .= s:line_term
-
-function s:OneScope(lnum,text,add)
-  return a:text =~# '\%(\<else\|\<do\|=>\)' . s:line_term ? 'no b' :
-        \ ((a:add && a:text =~ s:line_pre . '$' && search('\%' . s:PrevCodeLine(a:lnum - 1) . 'l.)' . s:line_term)) ||
-        \ cursor(a:lnum, match(a:text, ')' . s:line_term)) > -1) &&
-        \ s:GetPair('(', ')', 'cbW', 100) > 0 && search('\C\l\+\_s*\%#','bW') &&
-        \ (a:add || ((expand('<cword>') !=# 'while' || !s:GetPair('\C\<do\>', '\C\<while\>','nbW',100)) &&
-        \ (expand('<cword>') !=# 'each' || search('\C\<for\_s\+\%#','nbW')))) ? expand('<cword>') : ''
+function s:continues(ln,con)
+  return !cursor(a:ln, match(' '.a:con,s:continuation)) &&
+        \ eval((['s:syn_at(line("."),col(".")) !~? "regex"'] +
+        \ repeat(['s:previous_token() != "."'],5) + [1])[
+        \ index(split('/ typeof in instanceof void delete'),s:token())])
 endfunction
 
-" https://github.com/sweet-js/sweet.js/wiki/design#give-lookbehind-to-the-reader
-function s:IsBlock()
-  return getline(line('.'))[col('.')-1] == '{' && !search(
-        \ '\C\%(\<return\s*\|\%([-=~!<*+,.?^%|&\[(]\|=\@<!>\|\*\@<!\/\|\<\%(var\|const\|let\|import\|export\%(\_s\+default\)\=\|yield\|delete\|void\|t\%(ypeof\|hrow\)\|new\|in\%(stanceof\)\=\)\)\_s*\)\%#','bnW') &&
-        \ (!search(':\_s*\%#','bW') || (!s:GetPair('[({[]','[])}]','bW',200) || s:IsBlock()))
+" get the line of code stripped of comments and move cursor to the last
+" non-comment char.
+function s:Trim(ln)
+  let pline = substitute(getline(a:ln),'\s*$','','')
+  let l:max = max([match(pline,'.*[^/]\zs\/[/*]'),0])
+  while l:max && s:syn_at(a:ln, strlen(pline)) =~? s:syng_com
+    let pline = substitute(strpart(pline, 0, l:max),'\s*$','','')
+    let l:max = max([match(pline,'.*[^/]\zs\/[/*]'),0])
+  endwhile
+  return cursor(a:ln,strlen(pline)) ? pline : pline
 endfunction
 
-" Auxiliary Functions {{{2
-
-" Find line above 'lnum' that isn't empty, in a comment, or in a string.
+" Find line above 'lnum' that isn't empty or in a comment
 function s:PrevCodeLine(lnum)
-  let l:lnum = prevnonblank(a:lnum)
-  while l:lnum
-    if synIDattr(synID(l:lnum,matchend(getline(l:lnum), '^\s*[^''"]'),0),'name') !~? s:syng_strcom
-      return l:lnum
+  let l:n = prevnonblank(a:lnum)
+  while l:n
+    if getline(l:n) =~ '^\s*\/[/*]'
+      if (stridx(getline(l:n),'`') > 0 || getline(l:n-1)[-1:] == '\') &&
+            \ s:syn_at(l:n,1) =~? s:syng_str
+        return l:n
+      endif
+      let l:n = prevnonblank(l:n-1)
+    elseif s:syn_at(l:n,1) =~? s:syng_com
+      let l:n = s:save_pos('eval',
+            \ 'cursor('.l:n.',1) + search(''\m\/\*'',"bW")')
+    else
+      return l:n
     endif
-    let l:lnum = prevnonblank(l:lnum - 1)
   endwhile
 endfunction
 
 " Check if line 'lnum' has a balanced amount of parentheses.
 function s:Balanced(lnum)
-  let [open_0,open_2,open_4] = [0,0,0]
+  let l:open = 0
   let l:line = getline(a:lnum)
   let pos = match(l:line, '[][(){}]', 0)
   while pos != -1
-    if synIDattr(synID(a:lnum,pos + 1,0),'name') !~? s:syng_strcom
-      let idx = stridx('(){}[]', l:line[pos])
-      if idx % 2 == 0
-        let open_{idx} = open_{idx} + 1
-      else
-        let open_{idx - 1} = open_{idx - 1} - 1
+    if s:syn_at(a:lnum,pos + 1) !~? s:syng_strcom
+      let l:open += match(' ' . l:line[pos],'[[({]')
+      if l:open < 0
+        return
       endif
     endif
     let pos = match(l:line, '[][(){}]', pos + 1)
   endwhile
-  return (!open_4 + !open_2 + !open_0) - 2
+  return !l:open
+endfunction
+
+function s:OneScope(lnum)
+  let pline = s:Trim(a:lnum)
+  let kw = 'else do'
+  if pline[-1:] == ')' && s:GetPair('(', ')', 'bW', s:skip_expr, 100) > 0
+    call s:previous_token()
+    let kw = 'for if let while with'
+    if index(split('await each'),s:token()) + 1
+      call s:previous_token()
+      let kw = 'for'
+    endif
+  endif
+  return pline[-2:] == '=>' || index(split(kw),s:token()) + 1 &&
+        \ s:save_pos('s:previous_token') != '.'
 endfunction
-" }}}
+
+" returns braceless levels started by 'i' and above lines * &sw. 'num' is the
+" lineNr which encloses the entire context, 'cont' if whether line 'i' + 1 is
+" a continued expression, which could have started in a braceless context
+function s:iscontOne(i,num,cont)
+  let [l:i, l:num, bL] = [a:i, a:num + !a:num, 0]
+  let pind = a:num ? indent(l:num) + s:W : 0
+  let ind = indent(l:i) + (a:cont ? 0 : s:W)
+  while l:i >= l:num && (ind > pind || l:i == l:num)
+    if indent(l:i) < ind && s:OneScope(l:i)
+      let bL += s:W
+      let l:i = line('.')
+    elseif !a:cont || bL || ind < indent(a:i)
+      break
+    endif
+    let ind = min([ind, indent(l:i)])
+    let l:i = s:PrevCodeLine(l:i - 1)
+  endwhile
+  return bL
+endfunction
+
+" https://github.com/sweet-js/sweet.js/wiki/design#give-lookbehind-to-the-reader
+function s:IsBlock()
+  if s:looking_at() == '{'
+    let l:n = line('.')
+    let char = s:previous_token()
+    let syn = char =~ '[{>/]' ? s:syn_at(line('.'),col('.')-(char == '{')) : ''
+    if syn =~? 'xml\|jsx'
+      return char != '{'
+    elseif char =~ '\k'
+      return index(split('return const let import export yield default delete var await void typeof throw case new in instanceof')
+            \ ,char) < (line('.') != l:n) || s:previous_token() == '.'
+    elseif char == '>'
+      return getline('.')[col('.')-2] == '=' || syn =~? '^jsflow'
+    elseif char == ':'
+      return getline('.')[col('.')-2] != ':' && s:label_col()
+    endif
+    return syn =~? 'regex' || char !~ '[-=~!<*+,/?^%|&([]'
+  endif
+endfunction
 
 function GetJavascriptIndent()
-  if !exists('b:js_cache')
-    let b:js_cache = [0,0,0]
-  endif
+  let b:js_cache = get(b:,'js_cache',[0,0,0])
   " Get the current line.
-  let l:line = getline(v:lnum)
-  let syns = synIDattr(synID(v:lnum, 1, 0), 'name')
+  call cursor(v:lnum,1)
+  let l:line = getline('.')
+  let syns = s:syn_at(v:lnum, 1)
 
-  " start with strings,comments,etc.{{{2
-  if (l:line !~ '^[''"`]' && syns =~? '\%(string\|template\)') ||
-        \ (l:line !~ '^\s*[/*]' && syns =~? s:syng_comment)
+  " start with strings,comments,etc.
+  if syns =~? s:syng_com
+    if l:line =~ '^\s*\*'
+      return cindent(v:lnum)
+    elseif l:line !~ '^\s*\/[/*]'
+      return -1
+    endif
+  elseif syns =~? s:syng_str && l:line !~ '^[''"]'
+    if b:js_cache[0] == v:lnum - 1 && s:Balanced(v:lnum-1)
+      let b:js_cache[0] = v:lnum
+    endif
     return -1
   endif
-  if l:line !~ '^\%(\/\*\|\s*\/\/\)' && syns =~? s:syng_comment
-    return cindent(v:lnum)
-  endif
   let l:lnum = s:PrevCodeLine(v:lnum - 1)
-  if l:lnum == 0
-    return 0
+  if !l:lnum
+    return
   endif
 
-  if (l:line =~# s:expr_case)
-    let cpo_switch = &cpo
-    set cpo+=%
-    let ind = cindent(v:lnum)
-    let &cpo = cpo_switch
-    return ind
+  let l:line = substitute(l:line,'^\s*','','')
+  if l:line[:1] == '/*'
+    let l:line = substitute(l:line,'^\%(\/\*.\{-}\*\/\s*\)*','','')
   endif
-  "}}}
+  if l:line =~ '^\/[/*]'
+    let l:line = ''
+  endif
 
-  " the containing paren, bracket, curly. Memoize, last lineNr either has the
-  " same scope or starts a new one, unless if it closed a scope.
-  call cursor(v:lnum,1)
-  if b:js_cache[0] >= l:lnum  && b:js_cache[0] < v:lnum && b:js_cache[0] &&
-        \ (b:js_cache[0] > l:lnum || s:Balanced(l:lnum) > 0)
-    let num = b:js_cache[1]
-  elseif syns != '' && l:line[0] =~ '\s'
-    let pattern = syns =~? 'block' ? ['{','}'] : syns =~? 'jsparen' ? ['(',')'] :
-          \ syns =~? 'jsbracket'? ['\[','\]'] : ['[({[]','[])}]']
-    let num = s:GetPair(pattern[0],pattern[1],'bW',2000)
+  " the containing paren, bracket, or curly. Many hacks for performance
+  let idx = strlen(l:line) ? stridx('])}',l:line[0]) : -1
+  if b:js_cache[0] >= l:lnum && b:js_cache[0] < v:lnum &&
+        \ (b:js_cache[0] > l:lnum || s:Balanced(l:lnum))
+    call call('cursor',b:js_cache[1:])
   else
-    let num = s:GetPair('[({[]','[])}]','bW',2000)
+    let [s:looksyn, s:free, top] = [v:lnum - 1, 1, (!indent(l:lnum) &&
+          \ s:syn_at(l:lnum,1) !~? s:syng_str) * l:lnum]
+    if idx + 1
+      call s:GetPair(['\[','(','{'][idx], '])}'[idx],'bW','s:skip_func()',2000,top)
+    elseif indent(v:lnum) && syns =~? 'block'
+      call s:GetPair('{','}','bW','s:skip_func()',2000,top)
+    else
+      call s:alternatePair(top)
+    endif
   endif
-  let b:js_cache = [v:lnum,num,line('.') == v:lnum ? b:js_cache[2] : col('.')]
 
-  if l:line =~ s:line_pre . '[])}]'
-    return indent(num)
+  if idx + 1 || l:line[:1] == '|}'
+    if idx == 2 && search('\m\S','bW',line('.')) && s:looking_at() == ')'
+      call s:GetPair('(',')','bW',s:skip_expr,200)
+    endif
+    return indent('.')
   endif
 
-  call cursor(b:js_cache[1],b:js_cache[2])
+  let b:js_cache = [v:lnum] + (line('.') == v:lnum ? [0,0] : getpos('.')[1:2])
+  let num = b:js_cache[1]
 
-  let swcase = getline(l:lnum) =~# s:expr_case
-  let pline = swcase ? getline(l:lnum) : substitute(getline(l:lnum), '\%(:\@<!\/\/.*\)$', '','')
-  let inb = num == 0 || num < l:lnum && ((l:line !~ s:line_pre . ',' && pline !~ ',' . s:line_term) || s:IsBlock())
-  let switch_offset = num == 0 || s:OneScope(num, strpart(getline(num),0,b:js_cache[2] - 1),1) !=# 'switch' ? 0 :
-        \ &cino !~ ':' || !has('float') ?  s:sw() :
-        \ float2nr(str2float(matchstr(&cino,'.*:\zs[-0-9.]*')) * (&cino =~# '.*:[^,]*s' ? s:sw() : 1))
-
-  " most significant, find the indent amount
-  if inb && !swcase && ((l:line =~# g:javascript_opfirst || pline =~# g:javascript_continuation) ||
-        \ num < l:lnum && s:OneScope(l:lnum,pline,0) =~# '\<\%(for\|each\|if\|let\|no\sb\|w\%(hile\|ith\)\)\>' &&
-        \ l:line !~ s:line_pre . '{')
-    return (num > 0 ? indent(num) : -s:sw()) + (s:sw() * 2) + switch_offset
-  elseif num > 0
-    return indent(num) + s:sw() + switch_offset
+  let [s:W, isOp, bL, switch_offset] = [s:sw(),0,0,0]
+  if !num || s:IsBlock()
+    let pline = s:save_pos('s:Trim',l:lnum)
+    if num && s:looking_at() == ')' && s:GetPair('(', ')', 'bW', s:skip_expr, 100) > 0
+      let num = line('.')
+      if s:previous_token() ==# 'switch' && s:previous_token() != '.'
+        if &cino !~ ':' || !has('float')
+          let switch_offset = s:W
+        else
+          let cinc = matchlist(&cino,'.*:\(-\)\=\([0-9.]*\)\(s\)\=\C')
+          let switch_offset = float2nr(str2float(cinc[1].(strlen(cinc[2]) ? cinc[2] : strlen(cinc[3])))
+                \ * (strlen(cinc[3]) ? s:W : 1))
+        endif
+        if pline[-1:] != '.' && l:line =~# '^\%(default\|case\)\>'
+          return indent(num) + switch_offset
+        endif
+      endif
+    endif
+    if pline[-1:] !~ '[{;]'
+      if pline =~# ':\@<!:$'
+        call cursor(l:lnum,strlen(pline))
+        let isOp = s:tern_col(b:js_cache[1:2])
+      else
+        let isOp = l:line =~# s:opfirst || s:continues(l:lnum,pline)
+      endif
+      let bL = s:iscontOne(l:lnum,num,isOp)
+      let bL -= (bL && l:line[0] == '{') * s:W
+    endif
   endif
 
+  " main return
+  if isOp
+    return (num ? indent(num) : -s:W) + (s:W * 2) + switch_offset + bL
+  elseif num
+    return indent(num) + s:W + switch_offset + bL
+  endif
+  return bL
 endfunction
 
-
 let &cpo = s:cpo_save
 unlet s:cpo_save