Comp 232

Assignment #4

Due: Monday 10/23/2006

Solve the following problems.

a) Given the following grammar and the right sentential form, bBab, draw a parse tree and show the phrases and simple phrases, as well as the handle.

S -> aAb | bBA

A -> ab | aAB

B -> aB | b

(See page 203, problem 5b of the text.)

b) Design a state diagram to recognize one form of the comments of the C-based programming languages, those that begin with /* and end with */.

(See page 204, programming exercise 1 of the text.)

c) Some programming languages are typeless. What are the obvious advantages and disadvantages of having no types in a language?

(See page 244, problem 2 of the text.)

d) Assume the following Ada program was compiled and executed using static scoping rules. What value of X is printed in the procedure Sub1? Under dynamic scoping rules, what value of X is printed in procedure Sub1?

procedure Main is

X : Integer;

procedure Sub1 is

begin - - of Sub1

Put(X);

end; - - of Sub1

procedure Sub2 is

X : Integer;

begin - - of Sub2

X := 10;

Sub1

end; - - of Sub2

begin - - of Main

X := 5;

Sub2

end; - - of Main

(See page 245, problem 9 of the text.)