I dont find any info on backtrack on tango-D2 regex. For example, I want to match things like barFOObar or bazFOObaz so I would use, in PCRE, ^(\w*)FOO($1)$, with $1 meaning the word (given by \w* that was matced in the first subpattern (\w*) How to do the samein Tango for D2 (or even phobos for D2)?