I tested it by on a several megabyte text file (not that large) and I can see a huge improvement in speed when I use a reader vs. loading the whole thing into m

I tested it by on a several megabyte text file (not that large) and I can see a huge improvement in speed when I use a reader vs. loading the whole thing into memory as I did at first. I can see now how much of a difference it can make on a really large file, like in the gigabyte range. BTW, I deleted my earlier comment because the problem I had wasn't anything to do with bufio. I had just made an obvious mistake elsewhere in my code, which I've fixed now.