Identifiers
Lexer:
IDENTIFIER :
[a-zA-Z] [a-zA-Z0-9_]*
|_[a-zA-Z0-9_]+
An identifier is any nonempty ASCII string of the following form:
Either
- The first character is a letter
- The remaining characters are alphanumeric or
_
Or
- The first character is
_ - The identifier is more than one character,
_alone is not an identifier - The remaining characters are alphanumeric or
_