Thanks mate, I will definitely have a read.
In Go-land, you should be able to replace uses of memchr with IndexByte[1], which should be implemented in Assembly on most platforms.
Of course, for any of this to have a big impact, you'll want to take Mike Haertel's advice on avoiding line breaking and stop using bufio.Scanner. :-)
There are a couple of places I wish I would have done better. Using bufio.Scanner actually bothers me a lot. Also in the Read() method it reads everything from all readers into a buffer instead of pulling what it needs to check.
Thanks for suggestions :)