Unable to parse strings containing a lot of time intervals

An error is logged and the connection is closed abruptly when a string containing a lot of time intervals is sent to parse. This happens when the number of time intervals in the string is more than a certain threshold, it works fine otherwise (the time taken and the cpu usage is very high though).
Can such cases be handled in a more graceful manner?

Here's the error log:
[error.log](https://github.com/facebook/duckling/files/2759070/error.log)