class Parser::Builders::Default

def collection_map(begin_t, parts, end_t) 

def collection_map(begin_t, parts, end_t)
  if begin_t.nil? || end_t.nil?
    if parts.any?
      expr_l = join_exprs(parts.first, parts.last)
    end
  else
    expr_l = loc(begin_t).join(loc(end_t))
  end
  Source::Map::Collection.new(loc(begin_t), loc(end_t), expr_l)
end