Microgrammars are “partial grammars designed to extract checker-specific features only”.
When there is no out of the box support for a file type, and plain file manipulation is too clumsy and random, Atomist microgrammar (pdf) support allows you to safely pinpoint elements of files and edit them with clean diffs.
For more on microgrammars we recommend you check out this post by Adrian Colyer.
Please see the
implementation for the latest documentation and usage.