Example 1

Here, identifiers consist of letters and digits and begin with a letter; literals are sequences of digits; arithmetic operators are addition, subtraction, multiplication, division and assignment operators; punctuation symbols are ";" and left and right parentheses.

As input to a real lexical analyzer generator, this notation would be ambiguous since the left parenthesis is used in two ways. In the definition of an identifier, it is a metasymbol used for grouping, and in the definition of punctuation, it is an actual value.

Send questions and comment to: Karen Lemone