I am taking the Coursera class on compilers and in the lesson about lexers it is hinted that there is a time-space tradeoff between using non-deterministic finite automaton (NFA) and deterministic finite automaton (DFA) to parse regular expressions. If I understand correctly, the tradeoff is that a NFA is smaller, but is more time consuming to traverse because all possible states have to be regarded at the same time and therefore it is most of the time transformed into a DFA.  Are there any lexers that use NFAs instead of DFAs in real-life i.e. some compiler that is used in production and not a just a proof of concept?
Are there real lexers that use NFAs directly instead of first transforming them to DFAs?
finite automata;compilers;efficiency;nondeterminism;lexical analysis