Change python syntax providers, closes #209v3.3.0

2 files changed, 824 insertions, 175 deletions

diff --git a/indent/cython.vim b/indent/cython.vim
new file mode 100644
index 00000000..c6777c00
--- /dev/null
+++ b/indent/cython.vim
@@ -0,0 +1,433 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'python-ident') == -1
+  
+" PEP8 compatible Python indent file
+" Language:         Python
+" Maintainer:       Daniel Hahler <https://daniel.hahler.de/>
+" Prev Maintainer:  Hynek Schlawack <hs@ox.cx>
+" Prev Maintainer:  Eric Mc Sween <em@tomcom.de> (address invalid)
+" Original Author:  David Bustos <bustos@caltech.edu> (address invalid)
+" License:          CC0
+"
+" vim-python-pep8-indent - A nicer Python indentation style for vim.
+" Written in 2004 by David Bustos <bustos@caltech.edu>
+" Maintained from 2004-2005 by Eric Mc Sween <em@tomcom.de>
+" Maintained from 2013 by Hynek Schlawack <hs@ox.cx>
+" Maintained from 2017 by Daniel Hahler <https://daniel.hahler.de/>
+"
+" To the extent possible under law, the author(s) have dedicated all copyright
+" and related and neighboring rights to this software to the public domain
+" worldwide. This software is distributed without any warranty.
+" You should have received a copy of the CC0 Public Domain Dedication along
+" with this software. If not, see
+" <http://creativecommons.org/publicdomain/zero/1.0/>.
+
+" Only load this indent file when no other was loaded.
+if exists('b:did_indent')
+    finish
+endif
+let b:did_indent = 1
+
+setlocal nolisp
+setlocal autoindent
+setlocal indentexpr=GetPythonPEPIndent(v:lnum)
+setlocal indentkeys=!^F,o,O,<:>,0),0],0},=elif,=except
+
+if !exists('g:python_pep8_indent_multiline_string')
+    let g:python_pep8_indent_multiline_string = 0
+endif
+
+let s:block_rules = {
+            \ '^\s*elif\>': ['if', 'elif'],
+            \ '^\s*except\>': ['try', 'except'],
+            \ '^\s*finally\>': ['try', 'except', 'else']
+            \ }
+let s:block_rules_multiple = {
+            \ '^\s*else\>': ['if', 'elif', 'for', 'try', 'except'],
+            \ }
+" Pairs to look for when searching for opening parenthesis.
+" The value is the maximum offset in lines.
+let s:paren_pairs = {'()': 50, '[]': 100, '{}': 1000}
+
+if &filetype ==# 'pyrex' || &filetype ==# 'cython'
+    let b:control_statement = '\v^\s*(class|def|if|while|with|for|except|cdef|cpdef)>'
+else
+    let b:control_statement = '\v^\s*(class|def|if|while|with|for|except)>'
+endif
+let s:stop_statement = '^\s*\(break\|continue\|raise\|return\|pass\)\>'
+
+" Skip strings and comments. Return 1 for chars to skip.
+" jedi* refers to syntax definitions from jedi-vim for call signatures, which
+" are inserted temporarily into the buffer.
+let s:skip_special_chars = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "\\vstring|comment|jedi\\S"'
+
+let s:skip_after_opening_paren = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "\\vcomment|jedi\\S"'
+
+" Also ignore anything concealed.
+" Wrapper around synconcealed for older Vim (7.3.429, used on Travis CI).
+function! s:is_concealed(line, col)
+    let concealed = synconcealed(a:line, a:col)
+    return len(concealed) && concealed[0]
+endfunction
+if has('conceal')
+    let s:skip_special_chars .= '|| s:is_concealed(line("."), col("."))'
+endif
+
+
+let s:skip_search = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "comment"'
+
+" Use 'shiftwidth()' instead of '&sw'.
+" (Since Vim patch 7.3.629, 'shiftwidth' can be set to 0 to follow 'tabstop').
+if exists('*shiftwidth')
+    function! s:sw()
+        return shiftwidth()
+    endfunction
+else
+    function! s:sw()
+        return &shiftwidth
+    endfunction
+endif
+
+function! s:pair_sort(x, y)
+    if a:x[0] == a:y[0]
+        return a:x[1] == a:y[1] ? 0 : a:x[1] > a:y[1] ? 1 : -1
+    else
+        return a:x[0] > a:y[0] ? 1 : -1
+    endif
+endfunction
+
+" Find backwards the closest open parenthesis/bracket/brace.
+function! s:find_opening_paren(...)
+    " optional arguments: line and column (defaults to 1) to search around
+    if a:0 > 0
+        let view = winsaveview()
+        call cursor(a:1, a:0 > 1 ? a:2 : 1)
+        let ret = s:find_opening_paren()
+        call winrestview(view)
+        return ret
+    endif
+
+    " Return if cursor is in a comment.
+    exe 'if' s:skip_search '| return [0, 0] | endif'
+
+    let nearest = [0, 0]
+    for [p, maxoff] in items(s:paren_pairs)
+        let stopline = max([0, line('.') - maxoff, nearest[0]])
+        let next = searchpairpos(
+           \ '\V'.p[0], '', '\V'.p[1], 'bnW', s:skip_special_chars, stopline)
+        if next[0] && (next[0] > nearest[0] || (next[0] == nearest[0] && next[1] > nearest[1]))
+            let nearest = next
+        endif
+    endfor
+    return nearest
+endfunction
+
+" Find the start of a multi-line statement
+function! s:find_start_of_multiline_statement(lnum)
+    let lnum = a:lnum
+    while lnum > 0
+        if getline(lnum - 1) =~# '\\$'
+            let lnum = prevnonblank(lnum - 1)
+        else
+            let [paren_lnum, _] = s:find_opening_paren(lnum)
+            if paren_lnum < 1
+                return lnum
+            else
+                let lnum = paren_lnum
+            endif
+        endif
+    endwhile
+endfunction
+
+" Find possible indent(s) of the block starter that matches the current line.
+function! s:find_start_of_block(lnum, types, multiple)
+    let r = []
+    let types = copy(a:types)
+    let re = '\V\^\s\*\('.join(a:types, '\|').'\)\>'
+    let lnum = a:lnum
+    let last_indent = indent(lnum) + 1
+    while lnum > 0 && last_indent > 0
+        let indent = indent(lnum)
+        if indent < last_indent
+            for type in types
+                let re = '\v^\s*'.type.'>'
+                if getline(lnum) =~# re
+                    if !a:multiple
+                        return [indent]
+                    endif
+                    if index(r, indent) == -1
+                        let r += [indent]
+                    endif
+                    " Remove any handled type, e.g. 'if'.
+                    call remove(types, index(types, type))
+                endif
+            endfor
+            let last_indent = indent(lnum)
+        endif
+        let lnum = prevnonblank(lnum - 1)
+    endwhile
+    return r
+endfunction
+
+" Is "expr" true for every position in "lnum", beginning at "start"?
+" (optionally up to a:1 / 4th argument)
+function! s:match_expr_on_line(expr, lnum, start, ...)
+    let text = getline(a:lnum)
+    let end = a:0 ? a:1 : len(text)
+    if a:start > end
+        return 1
+    endif
+    let save_pos = getpos('.')
+    let r = 1
+    for i in range(a:start, end)
+        call cursor(a:lnum, i)
+        if !(eval(a:expr) || text[i-1] =~# '\s')
+            let r = 0
+            break
+        endif
+    endfor
+    call setpos('.', save_pos)
+    return r
+endfunction
+
+" Line up with open parenthesis/bracket/brace.
+function! s:indent_like_opening_paren(lnum)
+    let [paren_lnum, paren_col] = s:find_opening_paren(a:lnum)
+    if paren_lnum <= 0
+        return -2
+    endif
+    let text = getline(paren_lnum)
+    let base = indent(paren_lnum)
+
+    let nothing_after_opening_paren = s:match_expr_on_line(
+                \ s:skip_after_opening_paren, paren_lnum, paren_col+1)
+    let starts_with_closing_paren = getline(a:lnum) =~# '^\s*[])}]'
+
+    if nothing_after_opening_paren
+        if starts_with_closing_paren
+            let res = base
+        else
+            let res = base + s:sw()
+        endif
+    else
+        " Indent to match position of opening paren.
+        let res = paren_col
+    endif
+
+    " If this line is the continuation of a control statement
+    " indent further to distinguish the continuation line
+    " from the next logical line.
+    if text =~# b:control_statement && res == base + s:sw()
+        return base + s:sw() * 2
+    else
+        return res
+    endif
+endfunction
+
+" Match indent of first block of this type.
+function! s:indent_like_block(lnum)
+    let text = getline(a:lnum)
+    for [multiple, block_rules] in [
+                \ [0, s:block_rules],
+                \ [1, s:block_rules_multiple]]
+        for [line_re, blocks] in items(block_rules)
+            if text !~# line_re
+                continue
+            endif
+
+            let indents = s:find_start_of_block(a:lnum - 1, blocks, multiple)
+            if !len(indents)
+                return -1
+            endif
+            if len(indents) == 1
+                return indents[0]
+            endif
+
+            " Multiple valid indents, e.g. for 'else' with both try and if.
+            let indent = indent(a:lnum)
+            if index(indents, indent) != -1
+                " The indent is valid, keep it.
+                return indent
+            endif
+            " Fallback to the first/nearest one.
+            return indents[0]
+        endfor
+    endfor
+    return -2
+endfunction
+
+function! s:indent_like_previous_line(lnum)
+    let lnum = prevnonblank(a:lnum - 1)
+
+    " No previous line, keep current indent.
+    if lnum < 1
+      return -1
+    endif
+
+    let text = getline(lnum)
+    let start = s:find_start_of_multiline_statement(lnum)
+    let base = indent(start)
+    let current = indent(a:lnum)
+
+    " Jump to last character in previous line.
+    call cursor(lnum, len(text))
+    let ignore_last_char = eval(s:skip_special_chars)
+
+    " Search for final colon that is not inside something to be ignored.
+    while 1
+        let curpos = getpos('.')[2]
+        if curpos == 1 | break | endif
+        if eval(s:skip_special_chars) || text[curpos-1] =~# '\s'
+            normal! h
+            continue
+        elseif text[curpos-1] ==# ':'
+            return base + s:sw()
+        endif
+        break
+    endwhile
+
+    if text =~# '\\$' && !ignore_last_char
+        " If this line is the continuation of a control statement
+        " indent further to distinguish the continuation line
+        " from the next logical line.
+        if getline(start) =~# b:control_statement
+            return base + s:sw() * 2
+        endif
+
+        " Nest (other) explicit continuations only one level deeper.
+        return base + s:sw()
+    endif
+
+    let empty = getline(a:lnum) =~# '^\s*$'
+
+    " Current and prev line are empty, next is not -> indent like next.
+    if empty && a:lnum > 1 &&
+          \ (getline(a:lnum - 1) =~# '^\s*$') &&
+          \ !(getline(a:lnum + 1) =~# '^\s*$')
+      return indent(a:lnum + 1)
+    endif
+
+    " If the previous statement was a stop-execution statement or a pass
+    if getline(start) =~# s:stop_statement
+        " Remove one level of indentation if the user hasn't already dedented
+        if empty || current > base - s:sw()
+            return base - s:sw()
+        endif
+        " Otherwise, trust the user
+        return -1
+    endif
+
+    if !empty && s:is_dedented_already(current, base)
+        return -1
+    endif
+
+    " In all other cases, line up with the start of the previous statement.
+    return base
+endfunction
+
+" If this line is dedented and the number of indent spaces is valid
+" (multiple of the indentation size), trust the user.
+function! s:is_dedented_already(current, base)
+    let dedent_size = a:current - a:base
+    return (dedent_size < 0 && a:current % s:sw() == 0) ? 1 : 0
+endfunction
+
+" Is the syntax at lnum (and optionally cnum) a python string?
+function! s:is_python_string(lnum, ...)
+    let line = getline(a:lnum)
+    let linelen = len(line)
+    if linelen < 1
+      let linelen = 1
+    endif
+    let cols = a:0 ? type(a:1) != type([]) ? [a:1] : a:1 : range(1, linelen)
+    for cnum in cols
+        if match(map(synstack(a:lnum, cnum),
+                    \ "synIDattr(v:val, 'name')"), 'python\S*String') == -1
+            return 0
+        end
+    endfor
+    return 1
+endfunction
+
+function! GetPythonPEPIndent(lnum)
+    " First line has indent 0
+    if a:lnum == 1
+        return 0
+    endif
+
+    let line = getline(a:lnum)
+    let prevline = getline(a:lnum-1)
+
+    " Multilinestrings: continous, docstring or starting.
+    if s:is_python_string(a:lnum-1, len(prevline))
+                \ && (s:is_python_string(a:lnum, 1)
+                \     || match(line, '^\%("""\|''''''\)') != -1)
+
+        " Indent closing quotes as the line with the opening ones.
+        let match_quotes = match(line, '^\s*\zs\%("""\|''''''\)')
+        if match_quotes != -1
+            " closing multiline string
+            let quotes = line[match_quotes:(match_quotes+2)]
+            let pairpos = searchpairpos(quotes, '', quotes, 'b')
+            if pairpos[0] != 0
+                return indent(pairpos[0])
+            else
+                " TODO: test to cover this!
+            endif
+        endif
+
+        if s:is_python_string(a:lnum-1)
+            " Previous line is (completely) a string.
+            return indent(a:lnum-1)
+        endif
+
+        if match(prevline, '^\s*\%("""\|''''''\)') != -1
+            " docstring.
+            return indent(a:lnum-1)
+        endif
+
+        let indent_multi = get(b:, 'python_pep8_indent_multiline_string',
+                    \ get(g:, 'python_pep8_indent_multiline_string', 0))
+        if match(prevline, '\v%("""|'''''')$') != -1
+            " Opening multiline string, started in previous line.
+            if (&autoindent && indent(a:lnum) == indent(a:lnum-1))
+                        \ || match(line, '\v^\s+$') != -1
+                " <CR> with empty line or to split up 'foo("""bar' into
+                " 'foo("""' and 'bar'.
+                if indent_multi == -2
+                    return indent(a:lnum-1) + s:sw()
+                endif
+                return indent_multi
+            endif
+        endif
+
+        " Keep existing indent.
+        if match(line, '\v^\s*\S') != -1
+            return -1
+        endif
+
+        if indent_multi != -2
+            return indent_multi
+        endif
+
+        return s:indent_like_opening_paren(a:lnum)
+    endif
+
+    " Parens: If we can find an open parenthesis/bracket/brace, line up with it.
+    let indent = s:indent_like_opening_paren(a:lnum)
+    if indent >= -1
+        return indent
+    endif
+
+    " Blocks: Match indent of first block of this type.
+    let indent = s:indent_like_block(a:lnum)
+    if indent >= -1
+        return indent
+    endif
+
+    return s:indent_like_previous_line(a:lnum)
+endfunction
+
+endif
diff --git a/indent/python.vim b/indent/python.vim
index 48b34469..c6777c00 100644
--- a/indent/python.vim
+++ b/indent/python.vim
@@ -1,217 +1,433 @@
-if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'python') == -1
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'python-ident') == -1
   
 " PEP8 compatible Python indent file
+" Language:         Python
+" Maintainer:       Daniel Hahler <https://daniel.hahler.de/>
+" Prev Maintainer:  Hynek Schlawack <hs@ox.cx>
+" Prev Maintainer:  Eric Mc Sween <em@tomcom.de> (address invalid)
+" Original Author:  David Bustos <bustos@caltech.edu> (address invalid)
+" License:          CC0
+"
+" vim-python-pep8-indent - A nicer Python indentation style for vim.
+" Written in 2004 by David Bustos <bustos@caltech.edu>
+" Maintained from 2004-2005 by Eric Mc Sween <em@tomcom.de>
+" Maintained from 2013 by Hynek Schlawack <hs@ox.cx>
+" Maintained from 2017 by Daniel Hahler <https://daniel.hahler.de/>
+"
+" To the extent possible under law, the author(s) have dedicated all copyright
+" and related and neighboring rights to this software to the public domain
+" worldwide. This software is distributed without any warranty.
+" You should have received a copy of the CC0 Public Domain Dedication along
+" with this software. If not, see
+" <http://creativecommons.org/publicdomain/zero/1.0/>.
+
 " Only load this indent file when no other was loaded.
-if exists("b:did_indent")
+if exists('b:did_indent')
     finish
 endif
 let b:did_indent = 1
 
-setlocal expandtab
 setlocal nolisp
 setlocal autoindent
 setlocal indentexpr=GetPythonPEPIndent(v:lnum)
 setlocal indentkeys=!^F,o,O,<:>,0),0],0},=elif,=except
 
-let s:maxoff = 50
+if !exists('g:python_pep8_indent_multiline_string')
+    let g:python_pep8_indent_multiline_string = 0
+endif
+
+let s:block_rules = {
+            \ '^\s*elif\>': ['if', 'elif'],
+            \ '^\s*except\>': ['try', 'except'],
+            \ '^\s*finally\>': ['try', 'except', 'else']
+            \ }
+let s:block_rules_multiple = {
+            \ '^\s*else\>': ['if', 'elif', 'for', 'try', 'except'],
+            \ }
+" Pairs to look for when searching for opening parenthesis.
+" The value is the maximum offset in lines.
+let s:paren_pairs = {'()': 50, '[]': 100, '{}': 1000}
+
+if &filetype ==# 'pyrex' || &filetype ==# 'cython'
+    let b:control_statement = '\v^\s*(class|def|if|while|with|for|except|cdef|cpdef)>'
+else
+    let b:control_statement = '\v^\s*(class|def|if|while|with|for|except)>'
+endif
+let s:stop_statement = '^\s*\(break\|continue\|raise\|return\|pass\)\>'
+
+" Skip strings and comments. Return 1 for chars to skip.
+" jedi* refers to syntax definitions from jedi-vim for call signatures, which
+" are inserted temporarily into the buffer.
+let s:skip_special_chars = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "\\vstring|comment|jedi\\S"'
+
+let s:skip_after_opening_paren = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "\\vcomment|jedi\\S"'
+
+" Also ignore anything concealed.
+" Wrapper around synconcealed for older Vim (7.3.429, used on Travis CI).
+function! s:is_concealed(line, col)
+    let concealed = synconcealed(a:line, a:col)
+    return len(concealed) && concealed[0]
+endfunction
+if has('conceal')
+    let s:skip_special_chars .= '|| s:is_concealed(line("."), col("."))'
+endif
+
+
+let s:skip_search = 'synIDattr(synID(line("."), col("."), 0), "name") ' .
+            \ '=~? "comment"'
+
+" Use 'shiftwidth()' instead of '&sw'.
+" (Since Vim patch 7.3.629, 'shiftwidth' can be set to 0 to follow 'tabstop').
+if exists('*shiftwidth')
+    function! s:sw()
+        return shiftwidth()
+    endfunction
+else
+    function! s:sw()
+        return &shiftwidth
+    endfunction
+endif
+
+function! s:pair_sort(x, y)
+    if a:x[0] == a:y[0]
+        return a:x[1] == a:y[1] ? 0 : a:x[1] > a:y[1] ? 1 : -1
+    else
+        return a:x[0] > a:y[0] ? 1 : -1
+    endif
+endfunction
 
 " Find backwards the closest open parenthesis/bracket/brace.
-function! s:SearchParensPair()
-  let line = line('.')
-  let col = col('.')
-
-  " Skip strings and comments and don't look too far
-  let skip = "line('.') < " . (line - s:maxoff) . " ? dummy :" .
-        \ 'synIDattr(synID(line("."), col("."), 0), "name") =~? ' .
-        \ '"string\\|comment"'
-
-  " Search for parentheses
-  call cursor(line, col)
-  let parlnum = searchpair('(', '', ')', 'bW', skip)
-  let parcol = col('.')
-
-  " Search for brackets
-  call cursor(line, col)
-  let par2lnum = searchpair('\[', '', '\]', 'bW', skip)
-  let par2col = col('.')
-
-  " Search for braces
-  call cursor(line, col)
-  let par3lnum = searchpair('{', '', '}', 'bW', skip)
-  let par3col = col('.')
-
-  " Get the closest match
-  if par2lnum > parlnum || (par2lnum == parlnum && par2col > parcol)
-    let parlnum = par2lnum
-    let parcol = par2col
-  endif
-  if par3lnum > parlnum || (par3lnum == parlnum && par3col > parcol)
-    let parlnum = par3lnum
-    let parcol = par3col
-  endif
-
-  " Put the cursor on the match
-  if parlnum > 0
-    call cursor(parlnum, parcol)
-  endif
-  return parlnum
+function! s:find_opening_paren(...)
+    " optional arguments: line and column (defaults to 1) to search around
+    if a:0 > 0
+        let view = winsaveview()
+        call cursor(a:1, a:0 > 1 ? a:2 : 1)
+        let ret = s:find_opening_paren()
+        call winrestview(view)
+        return ret
+    endif
+
+    " Return if cursor is in a comment.
+    exe 'if' s:skip_search '| return [0, 0] | endif'
+
+    let nearest = [0, 0]
+    for [p, maxoff] in items(s:paren_pairs)
+        let stopline = max([0, line('.') - maxoff, nearest[0]])
+        let next = searchpairpos(
+           \ '\V'.p[0], '', '\V'.p[1], 'bnW', s:skip_special_chars, stopline)
+        if next[0] && (next[0] > nearest[0] || (next[0] == nearest[0] && next[1] > nearest[1]))
+            let nearest = next
+        endif
+    endfor
+    return nearest
 endfunction
 
 " Find the start of a multi-line statement
-function! s:StatementStart(lnum)
-  let lnum = a:lnum
-  while 1
-    if getline(lnum - 1) =~ '\\$'
-      let lnum = lnum - 1
-    else
-      call cursor(lnum, 1)
-      let maybe_lnum = s:SearchParensPair()
-      if maybe_lnum < 1
-        return lnum
-      else
-        let lnum = maybe_lnum
-      endif
-    endif
-  endwhile
+function! s:find_start_of_multiline_statement(lnum)
+    let lnum = a:lnum
+    while lnum > 0
+        if getline(lnum - 1) =~# '\\$'
+            let lnum = prevnonblank(lnum - 1)
+        else
+            let [paren_lnum, _] = s:find_opening_paren(lnum)
+            if paren_lnum < 1
+                return lnum
+            else
+                let lnum = paren_lnum
+            endif
+        endif
+    endwhile
 endfunction
 
-" Find the block starter that matches the current line
-function! s:BlockStarter(lnum, block_start_re)
-  let lnum = a:lnum
-  let maxindent = 10000       " whatever
-  while lnum > 1
-    let lnum = prevnonblank(lnum - 1)
-    if indent(lnum) < maxindent
-      if getline(lnum) =~ a:block_start_re
-        return lnum
-      else
-        let maxindent = indent(lnum)
-        " It's not worth going further if we reached the top level
-        if maxindent == 0
-          return -1
+" Find possible indent(s) of the block starter that matches the current line.
+function! s:find_start_of_block(lnum, types, multiple)
+    let r = []
+    let types = copy(a:types)
+    let re = '\V\^\s\*\('.join(a:types, '\|').'\)\>'
+    let lnum = a:lnum
+    let last_indent = indent(lnum) + 1
+    while lnum > 0 && last_indent > 0
+        let indent = indent(lnum)
+        if indent < last_indent
+            for type in types
+                let re = '\v^\s*'.type.'>'
+                if getline(lnum) =~# re
+                    if !a:multiple
+                        return [indent]
+                    endif
+                    if index(r, indent) == -1
+                        let r += [indent]
+                    endif
+                    " Remove any handled type, e.g. 'if'.
+                    call remove(types, index(types, type))
+                endif
+            endfor
+            let last_indent = indent(lnum)
         endif
-      endif
+        let lnum = prevnonblank(lnum - 1)
+    endwhile
+    return r
+endfunction
+
+" Is "expr" true for every position in "lnum", beginning at "start"?
+" (optionally up to a:1 / 4th argument)
+function! s:match_expr_on_line(expr, lnum, start, ...)
+    let text = getline(a:lnum)
+    let end = a:0 ? a:1 : len(text)
+    if a:start > end
+        return 1
     endif
-  endwhile
-  return -1
+    let save_pos = getpos('.')
+    let r = 1
+    for i in range(a:start, end)
+        call cursor(a:lnum, i)
+        if !(eval(a:expr) || text[i-1] =~# '\s')
+            let r = 0
+            break
+        endif
+    endfor
+    call setpos('.', save_pos)
+    return r
 endfunction
 
-function! GetPythonPEPIndent(lnum)
-  let scol = col('.')
-
-  " First line has indent 0
-  if a:lnum == 1
-    return 0
-  endif
-
-  " If we can find an open parenthesis/bracket/brace, line up with it.
-  call cursor(a:lnum, 1)
-  let parlnum = s:SearchParensPair()
-  if parlnum > 0
-    let parcol = col('.')
-    let matches = matchlist(getline(a:lnum), '^\(\s*\)[])}]')
-    if len(matches) == 0
-      let closing_paren = 0
-      let closing_paren_pos = 0
-    else
-      let closing_paren = 1
-      let closing_paren_pos = len(matches[1])
-    endif
-    if match(getline(parlnum), '[([{]\s*$', parcol - 1) != -1
-      if closing_paren
-        return indent(parlnum)
-      else
-        return indent(parlnum) + &shiftwidth
-      endif
-    elseif a:lnum - 1 != parlnum
-      if closing_paren && closing_paren_pos > scol
-        return indent(parlnum)
-      else
-        let lastindent = match(getline(a:lnum - 1), '\S')
-        if lastindent != -1 && lastindent < parcol
-          return lastindent
+" Line up with open parenthesis/bracket/brace.
+function! s:indent_like_opening_paren(lnum)
+    let [paren_lnum, paren_col] = s:find_opening_paren(a:lnum)
+    if paren_lnum <= 0
+        return -2
+    endif
+    let text = getline(paren_lnum)
+    let base = indent(paren_lnum)
+
+    let nothing_after_opening_paren = s:match_expr_on_line(
+                \ s:skip_after_opening_paren, paren_lnum, paren_col+1)
+    let starts_with_closing_paren = getline(a:lnum) =~# '^\s*[])}]'
+
+    if nothing_after_opening_paren
+        if starts_with_closing_paren
+            let res = base
+        else
+            let res = base + s:sw()
         endif
-      endif
+    else
+        " Indent to match position of opening paren.
+        let res = paren_col
     endif
 
-    " If we line up with an opening column there is a special case
-    " we want to handle: a docstring as argument.  In that case we
-    " don't want to line up with the paren but with the statement
-    " imagine foo(doc=""" as example
-    echo getline(parlnum)
-    if match(getline(parlnum), '\("""\|' . "'''" . '\)\s*$') != -1
-      return indent(parlnum)
+    " If this line is the continuation of a control statement
+    " indent further to distinguish the continuation line
+    " from the next logical line.
+    if text =~# b:control_statement && res == base + s:sw()
+        return base + s:sw() * 2
+    else
+        return res
     endif
+endfunction
 
-    return parcol
-  endif
+" Match indent of first block of this type.
+function! s:indent_like_block(lnum)
+    let text = getline(a:lnum)
+    for [multiple, block_rules] in [
+                \ [0, s:block_rules],
+                \ [1, s:block_rules_multiple]]
+        for [line_re, blocks] in items(block_rules)
+            if text !~# line_re
+                continue
+            endif
 
-  " Examine this line
-  let thisline = getline(a:lnum)
-  let thisindent = indent(a:lnum)
+            let indents = s:find_start_of_block(a:lnum - 1, blocks, multiple)
+            if !len(indents)
+                return -1
+            endif
+            if len(indents) == 1
+                return indents[0]
+            endif
 
-  " If the line starts with 'elif' or 'else', line up with 'if' or 'elif'
-  if thisline =~ '^\s*\(elif\|else\)\>'
-    let bslnum = s:BlockStarter(a:lnum, '^\s*\(if\|elif\)\>')
-    if bslnum > 0
-      return indent(bslnum)
-    else
+            " Multiple valid indents, e.g. for 'else' with both try and if.
+            let indent = indent(a:lnum)
+            if index(indents, indent) != -1
+                " The indent is valid, keep it.
+                return indent
+            endif
+            " Fallback to the first/nearest one.
+            return indents[0]
+        endfor
+    endfor
+    return -2
+endfunction
+
+function! s:indent_like_previous_line(lnum)
+    let lnum = prevnonblank(a:lnum - 1)
+
+    " No previous line, keep current indent.
+    if lnum < 1
       return -1
     endif
-  endif
 
-  " If the line starts with 'except' or 'finally', line up with 'try'
-  " or 'except'
-  if thisline =~ '^\s*\(except\|finally\)\>'
-    let bslnum = s:BlockStarter(a:lnum, '^\s*\(try\|except\)\>')
-    if bslnum > 0
-      return indent(bslnum)
-    else
-      return -1
+    let text = getline(lnum)
+    let start = s:find_start_of_multiline_statement(lnum)
+    let base = indent(start)
+    let current = indent(a:lnum)
+
+    " Jump to last character in previous line.
+    call cursor(lnum, len(text))
+    let ignore_last_char = eval(s:skip_special_chars)
+
+    " Search for final colon that is not inside something to be ignored.
+    while 1
+        let curpos = getpos('.')[2]
+        if curpos == 1 | break | endif
+        if eval(s:skip_special_chars) || text[curpos-1] =~# '\s'
+            normal! h
+            continue
+        elseif text[curpos-1] ==# ':'
+            return base + s:sw()
+        endif
+        break
+    endwhile
+
+    if text =~# '\\$' && !ignore_last_char
+        " If this line is the continuation of a control statement
+        " indent further to distinguish the continuation line
+        " from the next logical line.
+        if getline(start) =~# b:control_statement
+            return base + s:sw() * 2
+        endif
+
+        " Nest (other) explicit continuations only one level deeper.
+        return base + s:sw()
     endif
-  endif
-
-  " Examine previous line
-  let plnum = a:lnum - 1
-  let pline = getline(plnum)
-  let sslnum = s:StatementStart(plnum)
-
-  " If the previous line is blank, keep the same indentation
-  if pline =~ '^\s*$'
-    return -1
-  endif
-
-  " If this line is explicitly joined, try to find an indentation that looks
-  " good.
-  if pline =~ '\\$'
-    let compound_statement = '^\s*\(if\|while\|from\|import\|for\s.*\sin\|except\)\s*'
-    let maybe_indent = matchend(getline(sslnum), compound_statement)
-    if maybe_indent != -1
-      return maybe_indent
-    else
-      return indent(sslnum) + &sw * 2
+
+    let empty = getline(a:lnum) =~# '^\s*$'
+
+    " Current and prev line are empty, next is not -> indent like next.
+    if empty && a:lnum > 1 &&
+          \ (getline(a:lnum - 1) =~# '^\s*$') &&
+          \ !(getline(a:lnum + 1) =~# '^\s*$')
+      return indent(a:lnum + 1)
     endif
-  endif
 
-  " If the previous line ended with a colon and is not a comment, indent
-  " relative to statement start.
-  if pline =~ '^[^#]*:\s*\(#.*\)\?$'
-    return indent(sslnum) + &sw
-  endif
+    " If the previous statement was a stop-execution statement or a pass
+    if getline(start) =~# s:stop_statement
+        " Remove one level of indentation if the user hasn't already dedented
+        if empty || current > base - s:sw()
+            return base - s:sw()
+        endif
+        " Otherwise, trust the user
+        return -1
+    endif
+
+    if !empty && s:is_dedented_already(current, base)
+        return -1
+    endif
+
+    " In all other cases, line up with the start of the previous statement.
+    return base
+endfunction
+
+" If this line is dedented and the number of indent spaces is valid
+" (multiple of the indentation size), trust the user.
+function! s:is_dedented_already(current, base)
+    let dedent_size = a:current - a:base
+    return (dedent_size < 0 && a:current % s:sw() == 0) ? 1 : 0
+endfunction
+
+" Is the syntax at lnum (and optionally cnum) a python string?
+function! s:is_python_string(lnum, ...)
+    let line = getline(a:lnum)
+    let linelen = len(line)
+    if linelen < 1
+      let linelen = 1
+    endif
+    let cols = a:0 ? type(a:1) != type([]) ? [a:1] : a:1 : range(1, linelen)
+    for cnum in cols
+        if match(map(synstack(a:lnum, cnum),
+                    \ "synIDattr(v:val, 'name')"), 'python\S*String') == -1
+            return 0
+        end
+    endfor
+    return 1
+endfunction
+
+function! GetPythonPEPIndent(lnum)
+    " First line has indent 0
+    if a:lnum == 1
+        return 0
+    endif
+
+    let line = getline(a:lnum)
+    let prevline = getline(a:lnum-1)
+
+    " Multilinestrings: continous, docstring or starting.
+    if s:is_python_string(a:lnum-1, len(prevline))
+                \ && (s:is_python_string(a:lnum, 1)
+                \     || match(line, '^\%("""\|''''''\)') != -1)
+
+        " Indent closing quotes as the line with the opening ones.
+        let match_quotes = match(line, '^\s*\zs\%("""\|''''''\)')
+        if match_quotes != -1
+            " closing multiline string
+            let quotes = line[match_quotes:(match_quotes+2)]
+            let pairpos = searchpairpos(quotes, '', quotes, 'b')
+            if pairpos[0] != 0
+                return indent(pairpos[0])
+            else
+                " TODO: test to cover this!
+            endif
+        endif
+
+        if s:is_python_string(a:lnum-1)
+            " Previous line is (completely) a string.
+            return indent(a:lnum-1)
+        endif
+
+        if match(prevline, '^\s*\%("""\|''''''\)') != -1
+            " docstring.
+            return indent(a:lnum-1)
+        endif
+
+        let indent_multi = get(b:, 'python_pep8_indent_multiline_string',
+                    \ get(g:, 'python_pep8_indent_multiline_string', 0))
+        if match(prevline, '\v%("""|'''''')$') != -1
+            " Opening multiline string, started in previous line.
+            if (&autoindent && indent(a:lnum) == indent(a:lnum-1))
+                        \ || match(line, '\v^\s+$') != -1
+                " <CR> with empty line or to split up 'foo("""bar' into
+                " 'foo("""' and 'bar'.
+                if indent_multi == -2
+                    return indent(a:lnum-1) + s:sw()
+                endif
+                return indent_multi
+            endif
+        endif
+
+        " Keep existing indent.
+        if match(line, '\v^\s*\S') != -1
+            return -1
+        endif
+
+        if indent_multi != -2
+            return indent_multi
+        endif
+
+        return s:indent_like_opening_paren(a:lnum)
+    endif
+
+    " Parens: If we can find an open parenthesis/bracket/brace, line up with it.
+    let indent = s:indent_like_opening_paren(a:lnum)
+    if indent >= -1
+        return indent
+    endif
 
-  " If the previous line was a stop-execution statement or a pass
-  if getline(sslnum) =~ '^\s*\(break\|continue\|raise\|return\|pass\)\>'
-    " See if the user has already dedented
-    if indent(a:lnum) > indent(sslnum) - &sw
-      " If not, recommend one dedent
-      return indent(sslnum) - &sw
+    " Blocks: Match indent of first block of this type.
+    let indent = s:indent_like_block(a:lnum)
+    if indent >= -1
+        return indent
     endif
-    " Otherwise, trust the user
-    return -1
-  endif
 
-  " In all other cases, line up with the start of the previous statement.
-  return indent(sslnum)
+    return s:indent_like_previous_line(a:lnum)
 endfunction
 
 endif