Erlangのコードのインデントをemacsっぽく調整する(仮)

erl-format.rb

#!/usr/bin/env ruby
#
# emacs style erl formatter.
# usage: ruby erl-format.rb [-w] [target.erl]
#
save = false
if ARGV[0] == '-w'
  save = true
  ARGV.shift
end

if ARGV[0]
  files = ARGV
else
  files = `git status --porcelain`.lines.map{|l|l.chomp =~/..\s(.*\.erl)$/; $1}.compact
end

indent_conf={'fun' => 4, 'receive' => 4, 'case' => 4, 'try' => 4, 'end' => -8, 'spec' => 1, '->' => 0,
 '['=>1, ']' => -1, '{' => 1,'}' => -1, '(' => 1,')' => -1, '<<' => 2,'>>' => -2, '.' => -9, ';' => -1}

re = /(fun\s+[:\w]+\/|\d+\.+\d+|[\[\]\{\}\(\)\,;]|<<|>>|::|\.(?!\w)|\w*#\??\w+\{|(?<!\w)\w+(?!\w)|[>\/]?=[<:\/=]*|->|%.*|["].*?[^\\]["])/
files.each {|fname|
  STDERR.puts fname
  next unless File.file?(fname)
  output = []
  indents = []
  indent = 0
  locals = []
  local = 0
  tmp_indent = 0
  File.open(fname).read.each_line{|line|
    line.chomp!
    org = line.clone
    ii = indent + local + tmp_indent
    ii = (indents.last || 0) if line =~/^\s*(catch|after)(?!\w)/
    if line =~ re
      if indent_conf[$1] && indent_conf[$1] < 0
        if indent_conf[$1] > -9
          ii = [indent + (locals.last||0)+indent_conf[$1] ,0].max
        else
          ii = (indents.last || 0) + (locals.last || 0)
        end
      end
    end
    ii = 0 if ii < 0
    line.sub!(/^(\s*)(?=[^\s])/, " " * ii)
    line.scan(re) {
      a = $1
      b = $~.begin(0)
      if indent_conf[$1] && indent_conf[$1] >= 0
        indents << indent
        locals << local
        indent = $~.begin(0) + indent_conf[$1] - local if indent_conf[$1] > 0
        indent +=4 if indent_conf[$1] == 0
        tmp_indent = 0
      elsif indent_conf[$1]
        if $1 == '.'
          indents.clear
          locals.clear
        end
        if $1 == 'end'
          indent = indents.pop || 0
          local = locals.pop || 0
        end
        indent = indents.pop || 0
        local = locals.pop || 0
        tmp_indent = 0
      elsif  $1 == ','
        tmp_indent = 0
        local = locals.last || 0
      elsif  $1 == ';'
        tmp_indent = 0
      elsif $1 == '='
        tmp_indent = 4
      elsif $1 == '::'
        local = b + 1
      elsif $1 == '->'
        indent += 4
      elsif a =~/^\w*#\??\w+\{/
        indents << indent
        locals << local
        indent = b + indent_conf['{'] + 1 - local
        tmp_indent = 0
      end
    }
    # STDERR.puts org,line if line != org
    puts line if !save
    p indents if !save
    output << line
  }
  p indents if indents.length > 0
  File.open(fname, "wb").write(output.join("\n")+"\n") if save
}