Appendix B. Notation

none Syntax
Name ::= ...

Defines a grammar rule with name Name.

none Syntax
Rule1 | Rule2

Alternative: either Rule1 or Rule2.

none Syntax
Rule*

Zero or more occurrences of Rule.

none Syntax
Rule+

One or more occurrences of Rule.

none Syntax
Rule?

Zero or one occurrences of Rule.

none Syntax
'xyz'

An occurrence of xyz with proper tokenization. For example, 'case' does not match cases.