Lexical Elements of the Grammar

The lexical elements of the grammar which defines network files are listed as regular expresions. The first column lists the name of the symbol, the second the regular expresion defining it. The third column may contain comments.

• All terminals (characters) are put between SPM_amp"&...SPM_amp"&.

• Elements of sets are put between square brackets. Within the brackets, the characters represent themselves (even without SPM_amp"&), and - defines a range of values. The class of digits is defined, e.g. as SPM_amp["0"-"9"]&.

• Characters can be combined into groups with parenteses SPM_amp()&.

• SPM_ampx*& means, that the character or group x can occur zero or more times.

• SPM_ampx+& means, that the character or group x must occur at least once, but may occur several times.

• SPM_ampx?& means, that x can be omitted.

• SPM_ampxn& means, that x has to occur exactly n times.

• SPM_ampx|y& means, that either x or y has to occur.

• SPM_amp*&, SPM_amp+& and SPM_amp& bind strongest, SPM_amp?& is second, SPM_amp|& binds weakest.

• Groups or classes of characters are treated like a single character with respect to priority.