1. A method, comprising: selecting, based on a context relating to a domain of a regular expression, an ontology and an assertion base; parsing the regular expression to identify at least one fragment of the regular expression; identifying one or more assertions in the assertion base corresponding to one of the identified fragments; identifying, for each identified assertion, an associated node in the ontology; and returning, based on the associated nodes, a concept in the ontology as representing the associated fragment of the regular expression.