Before this was only possible when the match type is set to InformationalMatch. This did not include the cursorPosition feature and the text needed to be specified before the match is added.
To make sure the method can be called in AbstractRunner::run it is marked as const.
The usecase is a help functionality where the placeholder for the query should get focused so that the user can overwrite it by typing: https://phabricator.kde.org/F10042697
Also one could use it for the calculator or unitconverter runners.