The following declaration defines a list of identifiers where commas are used to separate list items. The last item in the list will not be followed by a comma. This definition does not allow the list to be completely empty.
Identifier = {Letter}{Alphanumeric}* <List>
::= <List> ',' <List Item> <List Item> ::= Identifier |
The following declaration defines a list of "Statements" where each <Statement> will be followed by a semicolon. Unlike the example above, the last item in the list will be followed by the symbol. However, since the <List> rule is nullable (the blank line), the list can be completely empty.
Identifier = {Letter}{Alphanumeric}* <List>
::= <List> <Statement> ';' <Statement> ::= print '(' Identifier ')' |
This is a declaration identical to the example above, except the list must contain at least one item.
Identifier = {Letter}{Alphanumeric}* <List>
::= <List> <Statement> ';' <Statement> ::= print '(' Identifier ')' |