function to get start, end, length form pattern match
text_locate default
text_locate(string, pattern, vectorize = FALSE, ...)# S3 method for default
text_locate(string, pattern, vectorize = FALSE, ...)
text to be searched through
regex to look for
should function be used in vectorized mode, i.e. should a pattern with length larger than 1 be allowed and if so, should it be matched to lines (with recycling if needed) instead of using on element on all lines
further options passed through to grep