A package for dependency graph (i.e. SemanticGraph) pattern expressions and matching these expressions to IndexedFeatureLabel instances. The design is similar to the `java.util.regex` package and based on the `edu.stanford.nlp.trees.tregex`. Internally, these expressions are parsed using a parser designed with the javacc "compiler compiler" utility.

See SemgrexPattern for a description of the command line utility version.

Note that the only classes which should be public are the SemgrexMatcher, SemgrexPattern and SemgrexPatternCompiler classes-- the others were automatically given public access by javacc although really they should be package-private. @author Chloe Kiddon