Regex in getGraphIds functions #12
Description
Currently, getGraphIds(), getGraphIdsInCorpus(), and getGraphIdsWithParticipant() only accept string literals for id. It would be nice if these accepted regular expressions as well. Ideally, to make them more R-native, they'd accept regex by default, with another argument fixed that's FALSE by default but that can be set to TRUE to make id a string literal (as with base R grep()); in that case, maybe id should be named pattern?