Imports of package tokenizer

PathSynopsis
encoding/hexPackage hex implements hexadecimal encoding and decoding.
errorsPackage errors implements functions to manipulate errors.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
ioPackage io provides basic interfaces to I/O primitives.
strconvPackage strconv implements conversions to and from string representations of basic data types.