class JMESPath::CachingParser

def cache_expression(expression)
  @mutex.synchronize do
    @cache.clear if @cache.size > 1000
    @cache[expression] = @parser.parse(expression)
  end
end

def initialize(options = {})
  @parser = options[:parser] || Parser.new(options)
  @mutex = Mutex.new
  @cache = {}
end

def parse(expression)
  if cached = @cache[expression]
    cached
  else
    cache_expression(expression)
  end
end