class Temple::Generator

def buffer
  options[:buffer]
end

def call(exp)
  [preamble, compile(exp), postamble].join('; ')
end

def compile(exp)
  type, *args = exp
  method = "on_#{type}"
  if respond_to?(method)
    send(method, *args)
  else
    raise InvalidExpression, "Generator supports only core expressions - found #{exp.inspect}"
  end
end

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

def on_capture(name, exp)
  options[:capture_generator].new(:buffer => name).call(exp)
end

def on_code(code)
  code
end

def on_dynamic(code)
  concat(code)
end

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

def on_newline
  "\n"
end

def on_static(text)
  concat(text.inspect)
end