I'm looking into doing some Regex with Tango. I'm interested in knowing which engine it uses. It claims to be based on the "Tagged NFA/DFA" however I can only get information on one or the other. It seems to be NFA because it has lazy, but according to http://www.regular- expressions.info/engine.html

"You can do the test by applying the regex r"regex|regex not" to the string "regex not". If the resulting match is only "regex", the engine is [NFA]. If the result is regex not, then it is [DFA]. The reason behind this is that the regex-directed engine is "eager".

So if for some reason Tango is mixing the two, where am I going to find accurate information on what is going on?