" Vim indent file
" Language:		Ruby
" Maintainer:		Nikolai Weibull 
" URL:			https://github.com/vim-ruby/vim-ruby
" Anon CVS:		See above site
" Release Coordinator:	Doug Kearns 

" 0. Initialization {{{1
" =================

" Only load this indent file when no other was loaded.
if exists("b:did_indent")
  finish
endif
let b:did_indent = 1

setlocal nosmartindent

" Now, set up our indentation expression and keys that trigger it.
setlocal indentexpr=GetRubyIndent(v:lnum)
setlocal indentkeys=0{,0},0),0],!^F,o,O,e
setlocal indentkeys+==end,=else,=elsif,=when,=ensure,=rescue,==begin,==end

" Only define the function once.
if exists("*GetRubyIndent")
  finish
endif

let s:cpo_save = &cpo
set cpo&vim

" 1. Variables {{{1
" ============

" Regex of syntax group names that are or delimit string or are comments.
let s:syng_strcom = '\'

" Regex of syntax group names that are strings.
let s:syng_string =
      \ '\'

" Regex of syntax group names that are strings or documentation.
let s:syng_stringdoc =
      \'\'

" Expression used to check whether we should skip a match with searchpair().
let s:skip_expr =
      \ "synIDattr(synID(line('.'),col('.'),1),'name') =~ '".s:syng_strcom."'"

" Regex used for words that, at the start of a line, add a level of indent.
let s:ruby_indent_keywords = '^\s*\zs\' .
      \ '\|\%([=,*/%+-]\|\|:\s\)\s*\zs' .
      \    '\'

" Regex used for words that, at the start of a line, remove a level of indent.
let s:ruby_deindent_keywords =
      \ '^\s*\zs\'

" Regex that defines the start-match for the 'end' keyword.
"let s:end_start_regex = '\%(^\|[^.]\)\'
" TODO: the do here should be restricted somewhat (only at end of line)?
let s:end_start_regex =
      \ '\C\%(^\s*\|[=,*/%+\-|;{]\|\|:\s\)\s*\zs' .
      \ '\' .
      \ '\|\'

" Regex that defines the middle-match for the 'end' keyword.
let s:end_middle_regex = '\\s*\%(#.*\)\=$')
  if col > 0
    call cursor(lnum, col)
    if searchpair(s:end_start_regex, '', s:end_end_regex, 'bW',
          \ s:end_skip_expr) > 0
      let n = line('.')
      let ind = indent('.')
      let msl = s:GetMSL(n)
      if msl != n
        let ind = indent(msl)
      end
      return ind
    endif
  end

  let col = s:Match(lnum, s:ruby_indent_keywords)
  if col > 0
    call cursor(lnum, col)
    let ind = virtcol('.') - 1 + &sw
    " TODO: make this better (we need to count them) (or, if a searchpair
    " fails, we know that something is lacking an end and thus we indent a
    " level
    if s:Match(lnum, s:end_end_regex)
      let ind = indent('.')
    endif
    return ind
  endif

  " 3.4. Work on the MSL line. {{{2
  " --------------------------

  " Set up variables to use and search for MSL to the previous line.
  let p_lnum = lnum
  let lnum = s:GetMSL(lnum)

  " If the previous line wasn't a MSL and is continuation return its indent.
  " TODO: the || s:IsInString() thing worries me a bit.
  if p_lnum != lnum
    if s:Match(p_lnum,s:non_bracket_continuation_regex)||s:IsInString(p_lnum,strlen(line))
      return ind
    endif
  endif

  " Set up more variables, now that we know we wasn't continuation bound.
  let line = getline(lnum)
  let msl_ind = indent(lnum)

  " If the MSL line had an indenting keyword in it, add a level of indent.
  " TODO: this does not take into account contrived things such as
  " module Foo; class Bar; end
  if s:Match(lnum, s:ruby_indent_keywords)
    let ind = msl_ind + &sw
    if s:Match(lnum, s:end_end_regex)
      let ind = ind - &sw
    endif
    return ind
  endif

  " If the previous line ended with [*+/.,-=], but wasn't a block ending,
  " indent one extra level.
  if s:Match(lnum, s:non_bracket_continuation_regex) && !s:Match(lnum, '^\s*\(}\|end\)')
    if lnum == p_lnum
      let ind = msl_ind + &sw
    else
      let ind = msl_ind
    endif
  endif

  " }}}2

  return ind
endfunction

" }}}1

let &cpo = s:cpo_save
unlet s:cpo_save

" vim:set sw=2 sts=2 ts=8 et: