This question: A data structure that maintain a set of strings, such that it returns strings matched by some regular expression was closed as not a real question (Note: It is not my question. Someone else has asked it).
It seems like a perfectly valid question to me. Is there some data structure which can support regex queries on some string repository. For an instance of an application of this, say you wanted to index the source code in your company. This type of a data structure might come in handy.
I admit I might be reading more than intended and it might be using subjective terms like 'efficient' and probably missing out some details (like single machine/distributed) etc, but it seems like a reasonable question. Objecively defining efficient each time would probably a waste of space/effort and time and the other info can easily be added. In any case, the question seems real enough to me, as it stands.
Can someone please explain why this is not a real question? Or get it reopened?