class RBS::Buffer

def initialize(name:, content:)
  @name = name
  @content = content
  @lines = content.lines
  @ranges = []
  offset = 0
  lines.each do |line|
    size = line.size
    range = offset...(offset+size)
    ranges << range
    offset += size
  end
end

def last_position
  content.size
end

def loc_to_pos(loc)
  line, column = loc
  if range = ranges[line - 1]
    range.begin + column
  else
    last_position
  end
end

def pos_to_loc(pos)
  index = ranges.bsearch_index do |range|
    pos < range.end ? true : false
  end
  if index
    [index + 1, pos - ranges[index].begin]
  else
    [ranges.size + 1, 0]
  end
end