Update runtime files. Add Rust support.

2 files changed, 341 insertions, 115 deletions

diff --git a/runtime/indent/javascript.vim b/runtime/indent/javascript.vim
index a6f1e1a8f8..304c0fe24f 100644
--- 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: December 31, 2016
+" Last Change: March 21, 2017
 
 " Only load this indent file when no other was loaded.
 if exists('b:did_indent')
@@ -14,6 +14,10 @@ let b:did_indent = 1
 setlocal indentexpr=GetJavascriptIndent()
 setlocal autoindent nolisp nosmartindent
 setlocal indentkeys+=0],0)
+" Testable with something like:
+" vim  -eNs "+filetype plugin indent on" "+syntax on" "+set ft=javascript" \
+"       "+norm! gg=G" '+%print' '+:q!' testfile.js \
+"       | diff -uBZ testfile.js -
 
 let b:undo_indent = 'setlocal indentexpr< smartindent< autoindent< indentkeys<'
 
@@ -32,10 +36,14 @@ if exists('*shiftwidth')
   endfunction
 else
   function s:sw()
-    return &sw
+    return &l:shiftwidth == 0 ? &l:tabstop : &l:shiftwidth
   endfunction
 endif
 
+" Performance for forwards search(): start search at pos rather than masking
+" matches before pos.
+let s:z = has('patch-7.4.984') ? 'z' : ''
+
 " searchpair() wrapper
 if has('reltime')
   function s:GetPair(start,end,flags,skip,time,...)
@@ -48,34 +56,41 @@ else
 endif
 
 " 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_strcom = 'string\|comment\|regex\|special\|doc\|template\%(braces\)\@!'
+let s:syng_str = 'string\|template\|special'
 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:parse_cino(f) abort
+  return float2nr(eval(substitute(substitute(join(split(
+        \ matchstr(&cino,'.*'.a:f.'\zs[^,]*'), 's',1), '*'.s:W)
+        \ , '^-\=\zs\*','',''), '^-\=\zs\.','0.','')))
+endfunction
+
 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
+  if getline('.') =~ '\%<'.col('.').'c\/.\{-}\/\|\%>'.col('.').'c[''"]\|\\$'
+    return eval(s:skip_expr)
+  elseif s:checkIn || search('\m`\|\${\|\*\/','nW'.s:z,s:looksyn)
+    let s:checkIn = eval(s:skip_expr)
   endif
   let s:looksyn = line('.')
-  return (search('\m\/','nbW',s:looksyn) || search('\m[''"]\|\\$','nW',s:looksyn)) && eval(s:skip_expr)
+  return s:checkIn
 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
+  let pat = '[][(){};]'
+  while search('\m'.pat,'bW',a:stop)
+    if s:skip_func() | continue | endif
+    let idx = stridx('])};',s:looking_at())
+    if idx is 3 | let pat = '[{}()]' | continue | endif
+    if idx + 1
+      if s:GetPair(['\[','(','{'][idx], '])}'[idx],'bW','s:skip_func()',2000,a:stop) <= 0
+        break
       endif
+    else
+      return
     endif
   endwhile
   call call('cursor',pos)
@@ -100,93 +115,91 @@ 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')
+  let l:pos = getpos('.')[1:2]
+  if search('\m\k\{1,}\zs\k\|\S','bW')
+    if (getline('.')[col('.')-2:col('.')-1] == '*/' || line('.') != l:pos[0] &&
+          \ getline('.') =~ '\%<'.col('.').'c\/\/') && s:syn_at(line('.'),col('.')) =~? s:syng_com
+      while search('\m\S\ze\_s*\/[/*]','bW')
+        if s:syn_at(line('.'),col('.')) !~? s:syng_com
+          return s:token()
+        endif
+      endwhile
     else
       return s:token()
     endif
-  endwhile
+  endif
+  call call('cursor',l:pos)
   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])
+function s:expr_col()
+  if getline('.')[col('.')-2] == ':'
+    return 1
   endif
+  let bal = 0
+  while search('\m[{}?:;]','bW')
+    if eval(s:skip_expr) | continue | endif
+    " switch (looking_at())
+    exe {   '}': "if s:GetPair('{','}','bW',s:skip_expr,200) <= 0 | return | endif",
+          \ ';': "return",
+          \ '{': "return getpos('.')[1:2] != b:js_cache[1:] && !s:IsBlock()",
+          \ ':': "let bal -= getline('.')[max([col('.')-2,0]):col('.')] !~ '::'",
+          \ '?': "let bal += 1 | if bal > 0 | return 1 | endif" }[s:looking_at()]
+  endwhile
 endfunction
 
 " configurable regexes that define continuation lines, not including (, {, or [.
 let s:opfirst = '^' . get(g:,'javascript_opfirst',
-      \ '\%([<>=,?^%|*/&]\|\([-.:+]\)\1\@!\|!=\|in\%(stanceof\)\=\>\)')
+      \ '\C\%([<>=,?^%|*/&]\|\([-.:+]\)\1\@!\|!=\|in\%(stanceof\)\=\>\)')
 let s:continuation = get(g:,'javascript_continuation',
-      \ '\%([<=,.~!?/*^%|&:]\|+\@<!+\|-\@<!-\|=\@<!>\|\<\%(typeof\|delete\|void\|in\|instanceof\)\)') . '$'
+      \ '\C\%([-+<>=,.~!?/*^%|&:]\|\<\%(typeof\|new\|delete\|void\|in\|instanceof\|await\)\)') . '$'
 
 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())])
+  if !cursor(a:ln, match(' '.a:con,s:continuation))
+    let teol = s:looking_at()
+    if teol == '/'
+      return s:syn_at(line('.'),col('.')) !~? 'regex'
+    elseif teol =~ '[-+>]'
+      return getline('.')[col('.')-2] != tr(teol,'>','=')
+    elseif teol =~ '\l'
+      return s:previous_token() != '.'
+    elseif teol == ':'
+      return s:expr_col()
+    endif
+    return 1
+  endif
 endfunction
 
 " 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])
+  let l:max = max([strridx(pline,'//'), strridx(pline,'/*')])
+  while l:max != -1 && s:syn_at(a:ln, strlen(pline)) =~? s:syng_com
+    let pline = pline[: l:max]
+    let l:max = max([strridx(pline,'//'), strridx(pline,'/*')])
+    let pline = substitute(pline[:-2],'\s*$','','')
   endwhile
-  return cursor(a:ln,strlen(pline)) ? pline : pline
+  return pline is '' || cursor(a:ln,strlen(pline)) ? pline : pline
 endfunction
 
 " Find line above 'lnum' that isn't empty or in a comment
 function s:PrevCodeLine(lnum)
-  let l:n = prevnonblank(a:lnum)
+  let [l:pos, l:n] = [getpos('.')[1:2], 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")')
+    elseif stridx(getline(l:n), '*/') + 1 && s:syn_at(l:n,1) =~? s:syng_com
+      call cursor(l:n,1)
+      keepjumps norm! [*
+      let l:n = search('\m\S','nbW')
     else
-      return l:n
+      break
     endif
   endwhile
+  call call('cursor',l:pos)
+  return l:n
 endfunction
 
 " Check if line 'lnum' has a balanced amount of parentheses.
@@ -201,7 +214,9 @@ function s:Balanced(lnum)
         return
       endif
     endif
-    let pos = match(l:line, '[][(){}]', pos + 1)
+    let pos = match(l:line, (l:open ?
+          \ '['.escape(tr(l:line[pos],'({[]})',')}][{(').l:line[pos],']').']' :
+          \ '[][(){}]'), pos + 1)
   endwhile
   return !l:open
 endfunction
@@ -210,11 +225,11 @@ 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
+    if s:previous_token() =~# '^\%(await\|each\)$'
       call s:previous_token()
       let kw = 'for'
+    else
+      let kw = 'for if let while with'
     endif
   endif
   return pline[-2:] == '=>' || index(split(kw),s:token()) + 1 &&
@@ -246,18 +261,23 @@ 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'
+    if match(s:stack,'\cxml\|jsx') + 1 && s:syn_at(line('.'),col('.')-1) =~? '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() == '.'
+      if char ==# 'type'
+        return s:previous_token() !~# '^\%(im\|ex\)port$'
+      endif
+      return index(split('return const let import export extends yield default delete var await void typeof throw case new of in instanceof')
+            \ ,char) < (line('.') != l:n) || s:save_pos('s:previous_token') == '.'
     elseif char == '>'
-      return getline('.')[col('.')-2] == '=' || syn =~? '^jsflow'
+      return getline('.')[col('.')-2] == '=' || s:syn_at(line('.'),col('.')) =~? '^jsflow'
     elseif char == ':'
-      return getline('.')[col('.')-2] != ':' && s:label_col()
+      return !s:save_pos('s:expr_col')
+    elseif char == '/'
+      return s:syn_at(line('.'),col('.')) =~? 'regex'
     endif
-    return syn =~? 'regex' || char !~ '[-=~!<*+,/?^%|&([]'
+    return char !~ '[=~!<*,?^%|&([]' &&
+          \ (char !~ '[-+]' || l:n != line('.') && getline('.')[col('.')-2] == char)
   endif
 endfunction
 
@@ -266,7 +286,9 @@ function GetJavascriptIndent()
   " Get the current line.
   call cursor(v:lnum,1)
   let l:line = getline('.')
-  let syns = s:syn_at(v:lnum, 1)
+  " use synstack as it validates syn state and works in an empty line
+  let s:stack = map(synstack(v:lnum,1),"synIDattr(v:val,'name')")
+  let syns = get(s:stack,-1,'')
 
   " start with strings,comments,etc.
   if syns =~? s:syng_com
@@ -275,7 +297,7 @@ function GetJavascriptIndent()
     elseif l:line !~ '^\s*\/[/*]'
       return -1
     endif
-  elseif syns =~? s:syng_str && l:line !~ '^[''"]'
+  elseif syns =~? s:syng_str
     if b:js_cache[0] == v:lnum - 1 && s:Balanced(v:lnum-1)
       let b:js_cache[0] = v:lnum
     endif
@@ -295,69 +317,60 @@ function GetJavascriptIndent()
   endif
 
   " the containing paren, bracket, or curly. Many hacks for performance
-  let idx = strlen(l:line) ? stridx('])}',l:line[0]) : -1
+  let idx = index([']',')','}'],l:line[0])
   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 [s:looksyn, s:free, top] = [v:lnum - 1, 1, (!indent(l:lnum) &&
+    let [s:looksyn, s:checkIn, top] = [v:lnum - 1, 0, (!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(['\[','(','{'][idx],'])}'[idx],'bW','s:skip_func()',2000,top)
+    elseif getline(v:lnum) !~ '^\S' && syns =~? 'block'
       call s:GetPair('{','}','bW','s:skip_func()',2000,top)
     else
       call s:alternatePair(top)
     endif
   endif
 
-  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
-
   let b:js_cache = [v:lnum] + (line('.') == v:lnum ? [0,0] : getpos('.')[1:2])
   let num = b:js_cache[1]
 
   let [s:W, isOp, bL, switch_offset] = [s:sw(),0,0,0]
   if !num || s:IsBlock()
+    let ilnum = line('.')
     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 num = ilnum == num ? line('.') : num
+      if idx < 0 && s:previous_token() ==# 'switch' && s:previous_token() != '.'
+        if &cino !~ ':'
           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))
+          let switch_offset = max([-indent(num),s:parse_cino(':')])
         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)
+    if idx < 0 && pline[-1:] !~ '[{;]'
+      let isOp = (l:line =~# s:opfirst || s:continues(l:lnum,pline)) * s:W
+      let bL = s:iscontOne(l:lnum,b:js_cache[1],isOp)
       let bL -= (bL && l:line[0] == '{') * s:W
     endif
+  elseif idx < 0 && getline(b:js_cache[1])[b:js_cache[2]-1] == '(' && &cino =~ '('
+    let pval = s:parse_cino('(')
+    return !pval ? (s:parse_cino('w') ? 0 : -(!!search('\m\S','W'.s:z,num))) + virtcol('.') :
+          \ max([indent('.') + pval + (s:GetPair('(',')','nbrmW',s:skip_expr,100,num) * s:W),0])
   endif
 
   " main return
-  if isOp
-    return (num ? indent(num) : -s:W) + (s:W * 2) + switch_offset + bL
+  if l:line =~ '^\%([])}]\||}\)'
+    return max([indent(num),0])
   elseif num
-    return indent(num) + s:W + switch_offset + bL
+    return indent(num) + s:W + switch_offset + bL + isOp
   endif
-  return bL
+  return bL + isOp
 endfunction
 
 let &cpo = s:cpo_save
diff --git a/runtime/indent/rust.vim b/runtime/indent/rust.vim
new file mode 100644
index 0000000000..a3051f0b06
--- /dev/null
+++ b/runtime/indent/rust.vim
@@ -0,0 +1,213 @@
+" Vim indent file
+" Language:         Rust
+" Author:           Chris Morgan <me@chrismorgan.info>
+" Last Change:      2017 Mar 21
+" For bugs, patches and license go to https://github.com/rust-lang/rust.vim
+
+" Only load this indent file when no other was loaded.
+if exists("b:did_indent")
+	finish
+endif
+let b:did_indent = 1
+
+setlocal cindent
+setlocal cinoptions=L0,(0,Ws,J1,j1
+setlocal cinkeys=0{,0},!^F,o,O,0[,0]
+" Don't think cinwords will actually do anything at all... never mind
+setlocal cinwords=for,if,else,while,loop,impl,mod,unsafe,trait,struct,enum,fn,extern
+
+" Some preliminary settings
+setlocal nolisp		" Make sure lisp indenting doesn't supersede us
+setlocal autoindent	" indentexpr isn't much help otherwise
+" Also do indentkeys, otherwise # gets shoved to column 0 :-/
+setlocal indentkeys=0{,0},!^F,o,O,0[,0]
+
+setlocal indentexpr=GetRustIndent(v:lnum)
+
+" Only define the function once.
+if exists("*GetRustIndent")
+	finish
+endif
+
+let s:save_cpo = &cpo
+set cpo&vim
+
+" Come here when loading the script the first time.
+
+function! s:get_line_trimmed(lnum)
+	" Get the line and remove a trailing comment.
+	" Use syntax highlighting attributes when possible.
+	" NOTE: this is not accurate; /* */ or a line continuation could trick it
+	let line = getline(a:lnum)
+	let line_len = strlen(line)
+	if has('syntax_items')
+		" If the last character in the line is a comment, do a binary search for
+		" the start of the comment.  synID() is slow, a linear search would take
+		" too long on a long line.
+		if synIDattr(synID(a:lnum, line_len, 1), "name") =~ 'Comment\|Todo'
+			let min = 1
+			let max = line_len
+			while min < max
+				let col = (min + max) / 2
+				if synIDattr(synID(a:lnum, col, 1), "name") =~ 'Comment\|Todo'
+					let max = col
+				else
+					let min = col + 1
+				endif
+			endwhile
+			let line = strpart(line, 0, min - 1)
+		endif
+		return substitute(line, "\s*$", "", "")
+	else
+		" Sorry, this is not complete, nor fully correct (e.g. string "//").
+		" Such is life.
+		return substitute(line, "\s*//.*$", "", "")
+	endif
+endfunction
+
+function! s:is_string_comment(lnum, col)
+	if has('syntax_items')
+		for id in synstack(a:lnum, a:col)
+			let synname = synIDattr(id, "name")
+			if synname == "rustString" || synname =~ "^rustComment"
+				return 1
+			endif
+		endfor
+	else
+		" without syntax, let's not even try
+		return 0
+	endif
+endfunction
+
+function GetRustIndent(lnum)
+
+	" Starting assumption: cindent (called at the end) will do it right
+	" normally. We just want to fix up a few cases.
+
+	let line = getline(a:lnum)
+
+	if has('syntax_items')
+		let synname = synIDattr(synID(a:lnum, 1, 1), "name")
+		if synname == "rustString"
+			" If the start of the line is in a string, don't change the indent
+			return -1
+		elseif synname =~ '\(Comment\|Todo\)'
+					\ && line !~ '^\s*/\*'  " not /* opening line
+			if synname =~ "CommentML" " multi-line
+				if line !~ '^\s*\*' && getline(a:lnum - 1) =~ '^\s*/\*'
+					" This is (hopefully) the line after a /*, and it has no
+					" leader, so the correct indentation is that of the
+					" previous line.
+					return GetRustIndent(a:lnum - 1)
+				endif
+			endif
+			" If it's in a comment, let cindent take care of it now. This is
+			" for cases like "/*" where the next line should start " * ", not
+			" "* " as the code below would otherwise cause for module scope
+			" Fun fact: "  /*\n*\n*/" takes two calls to get right!
+			return cindent(a:lnum)
+		endif
+	endif
+
+	" cindent gets second and subsequent match patterns/struct members wrong,
+	" as it treats the comma as indicating an unfinished statement::
+	"
+	" match a {
+	"     b => c,
+	"         d => e,
+	"         f => g,
+	" };
+
+	" Search backwards for the previous non-empty line.
+	let prevlinenum = prevnonblank(a:lnum - 1)
+	let prevline = s:get_line_trimmed(prevlinenum)
+	while prevlinenum > 1 && prevline !~ '[^[:blank:]]'
+		let prevlinenum = prevnonblank(prevlinenum - 1)
+		let prevline = s:get_line_trimmed(prevlinenum)
+	endwhile
+
+	" Handle where clauses nicely: subsequent values should line up nicely.
+	if prevline[len(prevline) - 1] == ","
+				\ && prevline =~# '^\s*where\s'
+		return indent(prevlinenum) + 6
+	endif
+
+	if prevline[len(prevline) - 1] == ","
+				\ && s:get_line_trimmed(a:lnum) !~ '^\s*[\[\]{}]'
+				\ && prevline !~ '^\s*fn\s'
+				\ && prevline !~ '([^()]\+,$'
+				\ && s:get_line_trimmed(a:lnum) !~ '^\s*\S\+\s*=>'
+		" Oh ho! The previous line ended in a comma! I bet cindent will try to
+		" take this too far... For now, let's normally use the previous line's
+		" indent.
+
+		" One case where this doesn't work out is where *this* line contains
+		" square or curly brackets; then we normally *do* want to be indenting
+		" further.
+		"
+		" Another case where we don't want to is one like a function
+		" definition with arguments spread over multiple lines:
+		"
+		" fn foo(baz: Baz,
+		"        baz: Baz) // <-- cindent gets this right by itself
+		"
+		" Another case is similar to the previous, except calling a function
+		" instead of defining it, or any conditional expression that leaves
+		" an open paren:
+		"
+		" foo(baz,
+		"     baz);
+		"
+		" if baz && (foo ||
+		"            bar) {
+		"
+		" Another case is when the current line is a new match arm.
+		"
+		" There are probably other cases where we don't want to do this as
+		" well. Add them as needed.
+		return indent(prevlinenum)
+	endif
+
+	if !has("patch-7.4.355")
+		" cindent before 7.4.355 doesn't do the module scope well at all; e.g.::
+		"
+		" static FOO : &'static [bool] = [
+		" true,
+		"	 false,
+		"	 false,
+		"	 true,
+		"	 ];
+		"
+		"	 uh oh, next statement is indented further!
+
+		" Note that this does *not* apply the line continuation pattern properly;
+		" that's too hard to do correctly for my liking at present, so I'll just
+		" start with these two main cases (square brackets and not returning to
+		" column zero)
+
+		call cursor(a:lnum, 1)
+		if searchpair('{\|(', '', '}\|)', 'nbW',
+					\ 's:is_string_comment(line("."), col("."))') == 0
+			if searchpair('\[', '', '\]', 'nbW',
+						\ 's:is_string_comment(line("."), col("."))') == 0
+				" Global scope, should be zero
+				return 0
+			else
+				" At the module scope, inside square brackets only
+				"if getline(a:lnum)[0] == ']' || search('\[', '', '\]', 'nW') == a:lnum
+				if line =~ "^\\s*]"
+					" It's the closing line, dedent it
+					return 0
+				else
+					return &shiftwidth
+				endif
+			endif
+		endif
+	endif
+
+	" Fall back on cindent, which does it mostly right
+	return cindent(a:lnum)
+endfunction
+
+let &cpo = s:save_cpo
+unlet s:save_cpo