> maybe even playing with colors to indicate if verbs form a train or other composition. I understand that is a quite different problem from just substituting @: with o̲.
With regards to how different of a problem that would be, J's syntax is context-sensitive. If you were to accurately identify trains and forks, you could not use regex, and would probably end up implementing a subset of the J parser.
With regards to how different of a problem that would be, J's syntax is context-sensitive. If you were to accurately identify trains and forks, you could not use regex, and would probably end up implementing a subset of the J parser.