Lexical ANTLR description for the integer constants of the C programming language
Such strings either start with a decimal digit different from
0 and
in such a case describe a natural number in base
10 with any amount
of digits between
0 and
9, or start with
0
and in such a case describe a natural number in base
8
with any amount of digits between
0 and
7, or start with
0x or
0X and are followed by the description
of an hexadecimal number
with one or more digits and
symbols between
a and
f, perhaps uppercase.
Integer numbers have two
optional suffixes: the length specifier (
l,
ll,
L,
LL) and the unsignedness (
u,
U). These suffixes can appear
in any order.