class Temple::Generator

def self.to_ruby(str)
  str.inspect
end

def buffer(str = '')
  @options[:buffer] + str
end

def capture_generator
  @capture_generator ||=
    @options[:capture_generator] || Temple::Core::StringBuffer
end

def compile(exp, single = false)
  if @compiling || single
    type, *args = exp
    recv = @in_capture || self
    recv.send("on_#{type}", *args)
  else
    begin
      @compiling = true
      [preamble, compile(exp), postamble].join(' ; ')
    ensure
      @compiling = false
    end
  end
end

def concat(str)
  buffer " << (#{str})"
end

def initialize(options = {})
  @options = DEFAULT_OPTIONS.merge(options)
  @compiling = false
  @in_capture = nil
end

def on_capture(name, block)
  before = @capture
  @capture = capture_generator.new(:buffer => name)
  [
    @capture.preamble,
    @capture.compile(block, true),
    "#{name} = (#{@capture.postamble})"
  ].join(' ; ')
ensure
  @capture = before
end

def on_multi(*exp)
  exp.map { |e| compile(e) }.join(" ; ")
end

def on_newline
  "\n"
end

def postamble; '' end

def preamble;  '' end

def to_ruby(str)
  Generator.to_ruby(str)
end