Semantics - Attributes Grammar: Using the following grammar write an attributes grammar that can calculate the decimal value of an octal number. Grammar: number = list list = list octal | octal octal = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 Notes: An octal number consists of octal digits, i.e. 0 to 7.

The following example shows how to convert the octal 67 to its equivalent decimal. The symbol star represents multiplication:-

67 = 6 * 81 + 7 * 80 = 6 * 8 + 7 = 55

Questions:

1. a) Introduce an attribute.

1. b) Specify the type of your attribute, i.e. intrinsic, inherited, or synthesized.

1. c) Write the attributes grammar (Syntax rule, Semantic rule, Semantic condition) for every grammar rule.