In this assignment, you will use top-down parsing rather than bottom-up parsing (as implemented using YACC).

Consider Boolean expressions, with the following operations: and, or, and not (standard associativity and precedence), brackets are allowed. If below you are asked to "write ...", then you have to include the required description as a part of your documentation. If you are asked to "implement...", then you have to write a program.

Part 1. Write an S-attributed syntax directed translation for Boolean expressions with the following tokens:

true, false, and brackets, which can be used to evaluate these expressions. Note: carefully study examples from the textbook of S-attributed syntax directed translations for arithmetic expressions, to learn how to design them to express correct precedence and associativity rules.

Then, write an L-attributed translation resulting from removing left recursion. Note: carefully study examples from the textbook showing how left-recursive S-attributed translations can be converted to L-attributed translations.

Finally, implement a lexical analyzer (use Lex or write it by hand) and a recursive-descent translator based on the above translation.

Examples:

true and not false

not false or (false and not false and true or false)

are both correct, and evaluate to true, but

1 and true

is invalid.

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* You have to use C++ or C

* And you have to look at the textbook (Aho, A.A., Sethi, R., & Ullman, J.D. (1986). Compilers. Principles, Techniques, and Tools. Boston, MA: Addison-Wesley, ISBN: 0201100886.)