5.1 Identifier format
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Identifiers in C-- must begin with an underscore '_' or uppercase or
lowercase letters. The following characters may be any combination of
underscore, uppercase or lowercase letters, or numbers (0 to 9). An
identifier may be no more than 64 characters long. Characters above 0x7A
('z') are not permitted.
Examples of valid identifiers:
_DOG
Loony12
HowdYBoys_AND_Girls
WOW___
X
Examples of invalid identifiers:
12bogus /* can not begin with a number */
WowisthisalongidentifieryupitsureisnotOyoulengthismorethat64chars
/* identifier longer than 64 characters */
Y_es sir /* space not permitted */
The-end /* hyphen not permitted */