Grammar parsing can be time consuming, but after development is finished, they change infrequently. CoffeePot can automatically cache compiled versions of grammars and use them automatically if they are up-to-date (based on last modified time).

(You can do this manually, by saving the compiled grammars and loading them explicitly, but using a cache saves a little time and effort.)

The location of cached grammars is controlled by cache setting in the configuration file. If the cache is a relative location (such as .grammar-cache), the compiled grammars are stored in the cache with the same filename as the original grammar except that the extension is changed. If the location is absolute (begins with a "/"; such as /home/user/.config/nineml/grammar-cache), the name of the cached file is a cryptographic hash of the original absolute filename.

The cache directory must be configured; if it's unconfigured, no caching is performed.