zero Zero ZERO
= 0
= 123
= .4e-5
= +3e5
= -43
x"ff"
----------------------------------------------------
[
["number", "zero"], ["number", "Zero"], ["number", "ZERO"],
["operator", "="], ["number", "0"],
["operator", "="], ["number", "123"],
["operator", "="], ["number", ".4e-5"],
["operator", "="], ["number", "+3e5"],
["operator", "="], ["number", "-43"],
["string", "x\"ff\""]
]