Lectures from 5 to 10

1.

5 points

Which are examples of dynamic rules?

*select all that apply.

Checking that pointers are not dereferenced unless pointing to a valid object

Checking that a variable was not used without been initialized

None of these

Checking that identifiers are used in appropriate context

Checking array subscript values to make sure they are within bounds(not the same as segment faults. Segment faults are handle by hardware.)

Checking arithmetic errors

2.

1 point

if b is an attribute associated with A, its called a synthesized attribute.

True

False

3.

1 point

Let L and M be two languages:
L={a, b, c}, M = {ee} – Formal definition of regular expression
L*(L+) = {_______}

abc,aabbcc,aaabbbccc,...

aee,bee,cee

a,b,c,aa,bb,cc,aaa,bbb,...

a,b,c,ee

4.

1 point

NFA uses finete state machines to recognize a string.

True

False

5.

1 point

What are the general parsing approaches?

a)Expanding from the start symbol to the whole program

a and b

Not a or b

b)Reduction from the whole program to the start symbol

6.

1 point

what grammar does the following recognize?

start → id ‘(‘ exp more_exp ‘)’
more_exp: ‘,’ exp more_exp | ε

*if more than one, select all that apply

id (exp1, exp2, …. )

exp1 (id1, id2, id3)

id (exp1) exp2

id (exp) id

7.

1 point

_______-_______ derivation is when the nonterminal on the far left in a sentential form is replaced in each derivation step

Type answer is two words. use only lower case letters and separate them with a coma.

example:
word1,word2

8.

1 point

What is an attribute grammar?

a)A grammar with each production associated with semantic actions that may modify attributes associated with grammar symbols.

b)This links syntax with semantics.

c)This was seen in project 2

d)a,b and c

e)a and b only

9.

1 point

What does a parser do?

*select all that apply.

Detects whether the program is written following the grammar rules and reports syntax errors

None of these choices

Produces a parse tree from which intermediate code can be generated

Detects whether the program has the correct types and reports semantic errors

10.

1 point

A Grammar is called S-attributed if all attributes are synthesized

True

False

11.

1 point

_______-_______ derivation is when the nonterminal on the far right in a sentential form is replaced in each derivation step.

Type answer is two words. use only lower case letters and separate them with a coma.

example:
word1,word2

12.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is first(T)={___________}

+

(

id

$

)

num

ε

13.

1 point

Regular expressions cannot use recursive definitions

True

False

14.

1 point

A grammar is called L-attributed if the parse tree traversal to update attribute values is always left-to-right and depth-first

True

False

15.

3 points

What language is being represented by the following image?

***Don't use upper case letters, and don't use any blank spaces.

16.

1 point

Is it wrong for a vegetarian to eat animal crackers?

Yes

No

Yes and No

It doesn't matter right now.

17.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is first(F)={___________}

id

$

+

ε

num

)

(

18.

3 points

What language is being represented by the following image?

***Don't use upper case letters, and don't use any blank spaces.

19.

1 point

When was the first video game invented?

I dont' know

1965

1961

don't pick this one

20.

1 point

ambiguous grammar is when there exist only one parse tree(branch) for the same grammar and input.

True

False

21.

1 point

How does the guy who drives the snowplow get to work in the mornings?

I don't care, I just want a free point

Mind blow!!!?

mhm?

I don't know

22.

5 points

which are examples of static semantic rules

*select all that apply.

none of these

Checking subroutine call arguments

Type checking

Checking that pointers are not dereferenced unless pointing to a valid object

Checking that identifiers are used in appropriate context

checking labels

23.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is follow(F)={___________}

ε

+

num

(

$

id

)

24.

1 point

Sneezing with your eyes open is impossible.

True

False

25.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is first(S)={___________}

+

)

(

num

ε

id

$

26.

1 point

Let L and M be two languages:
L={a, b, c}, M = {ee} – Formal definition of regular expression
LM = {_______}

a,b,c,ee

aee,bee,cee

a,b,c,aa,bb,cc,aaa,bbb,...

a,b,c

27.

1 point

a parse tree Depicts the end result of a derivation.

True

False

28.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is follow(T)={___________}

)

+

$

(

id

ε

num

29.

1 point

What is a token?

A token is a coin used at Chucky Cheese.

A token is a group of characters having a collective meaning.

A token is a rule describing how strings are formed.

None of these choices

30.

6 points

What are the components of grammar?

*select all that apply.

Terminals

Special terminals

Special non-terminal

Productions

Non-terminals

None of these choices

31.

6 points

Consider the following LL(1) grammar with terminals (, ), +, id, num, and
starting symbol S.

1. S → F
2. S → ( S T )
3. T → ε
4. T → + F T
5. F → id
6. F → num

What is follow(S)={___________}

+

num

$

)

(

ε

id

32.

1 point

if b is an attribute associated with a grammar symbol on the right side of the production, b is called an inherited attribute

True

False

33.

1 point

Let L and M be two languages:
L={a, b, c}, M = {ee} – Formal definition of regular expression
LUM = {_______}

a,b,c

a,ab,abc,abcee

aaa,bbb,ccc

a,b,c,ee

34.

1 point

NFA stands for "Non-deterministic Finite Automata"

True

False