class Temple::Generator

def self.to_ruby(str)
  str.inspect.gsub(/(\\r)?\\n/m) do |str|
    if $`[-1] == ?\\
      str
    elsif $1
      "\\n"
    else
      "\n"
    end
  end
end

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

def compile(exp)
  res = send("on_#{exp.first}", *exp[1..-1])
  
  if @in_multi && CONCATABLE.include?(exp.first)
    concat(res)
  else
    res
  end
end

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

def initialize(options = {})
  @options = DEFAULT_OPTIONS.merge(options)
  @in_multi = false
end

def on_capture(name, block)
  unless @in_multi
    # We always need the preamble/postamble in capture.
    return compile([:multi, [:capture, name, block]])
  end
  
  @in_multi = false
  prev_buffer, @options[:buffer] = @options[:buffer], name.to_s
  content = compile(block)
  @in_multi = true
  
  if CONCATABLE.include?(block.first)
    "#{name} = #{content}"
  else
    content
  end
ensure
  @options[:buffer] = prev_buffer
end

def on_multi(*exp)
  if @in_multi
    exp.map { |e| compile(e) }
  else
    @in_multi = true
    content = exp.map { |e| compile(e) }
    content = [preamble, content, postamble].flatten
    @in_multi = false
    content
  end.join(" ; ")
end

def on_newline
  "\n"
end

def postamble; '' end

def preamble;  '' end

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