class Opal::Nodes::MassAssignNode

def compile
  tmp = scope.new_temp
  len = 0 # how many rhs items are we sure we have
  if rhs.type == :array
    len = rhs.size - 1
    push "#{tmp} = ", expr(rhs)
  elsif rhs.type == :to_ary
    push "#{tmp} = $opal.to_ary(", expr(rhs[1]), ")"
  elsif rhs.type == :splat
    push "(#{tmp} = ", expr(rhs[1]), ")['$to_a'] ? (#{tmp} = #{tmp}['$to_a']())"
    push " : (#{tmp})._isArray ? #{tmp} : (#{tmp} = [#{tmp}])"
  else
    raise "unsupported mlhs type"
  end
  lhs.children.each_with_index do |child, idx|
    push ', '
    if child.type == :splat
      if part = child[1]
        part = part.dup
        part << s(:js_tmp, "$slice.call(#{tmp}, #{idx})")
        push expr(part)
      end
    else
      if idx >= len
        assign = s(:js_tmp, "(#{tmp}[#{idx}] == null ? nil : #{tmp}[#{idx}])")
      else
        assign = s(:js_tmp, "#{tmp}[#{idx}]")
      end
      part = child.dup
      if child.type == :lasgn or child.type == :iasgn or child.type == :lvar or child.type == :gasgn
        part << assign
      elsif child.type == :call
        part[2] = "#{part[2]}=".to_sym
        part.last << assign
      elsif child.type == :attrasgn
        part.last << assign
      else
        raise "Bad lhs for masgn"
      end
      push expr(part)
    end
  end
  scope.queue_temp tmp
end