Ask Question, Ask an Expert


Ask Computer Engineering Expert

problem 1: Given the production:

S-> aSAb | Ab
A-> bbb
implement a complete pseudo code for a recursive descent parser. Assume scanner ( ) returns the next token.

problem 2: Give all needed first and follow sets needed to check if the grammar is LL(1). Is it?:

S -> aA | BB
A -> aaA | empty
B -> bB | Cd
C -> cA | dC

problem 3: A function returns a number, takes no arguments, and its body is a block. Functions are defined exactly like variables in the grammar except that function name is follow by a block. Show the grammar. Is the resulting grammar LL(1)?

problem 4: A function definition must be before the program token, and functions cannot be nested (exactly like in C). Every function has a return type (no void) and one argument. Function call is like in C, with an expression for the argument and the function call itself is an expression. Show the grammar. exs:

int fun1(long x)
/* same as in any block*/
long fun2(int x)
/** ... */
program xxx(void)
int x;

problem 5: Design unambiguous grammar to parse expressions involving +, -, *, / and unary -. Unary minus is strongest, followed by * and /(same precedence, right associative), then +, left associative, then finally -, left associative. Do not use any other operators, and use only number tokens.

problem 6: Assume function f ( ) has local variables a, b, and function g is nested inside of f ( ) and has local variable a. There is also a global variable c.

a) show the complete memory space for the program when it begins execution
b) show the stack after f ( ) is called, which subsequently calls g ( ), which calls itself once.
c) assume we have three statements in g ( )

stat1: c=10;
stat2: a=20;
stat3: b=30;
how would they be translated by the compiler: describe in words.

problem 7: Show the grammar for:

a) Allow global variables placed just before the first begin – these variables are optional and are listed separated by commas. For ex:

int x,y,z;
begin {etc.}

b) Also allow functions. Each function takes any number of arguments and always returns an integer. Parameter list is C-like, and the return statement (followed by an expression) is mandatory. Functions can be called in place of any expression. Functions are defined with a block, which is the same as the begin-end block in our grammar. Functions are defined separately, as in C but before the main program. Assume we have a multi-pass compiler so that prototypes is not an issue. The following is an ex program

int sum(int a, b) {paramater list is same as for globals}
int c;
return a+b;
int x,y;

problem 8: Given the program (like Pascal, with nested functions)

int x, y; {global}
function A
int z; {z is in A}
function B {B is defined inside A}
int x; {x is in B}
function C {C is inside B}
int x; {x is in C}
C(); {recursive call on C}
end; {end of C}
end; {end of B}
B(); { A calls B}
end; {end of A}

a) show ARs (activation Records) for A, B, C (show only local data, static and dynamic link}
b) What is in the persistent data space?
c) assume call to A() is done somewhere. Then, show that contents of the stack during the 3rd recursive call to C(). Make sure to fill out all info on the stack.
d) How would the left-hand-side variables in C()be translated by the compiler (describe in words, separately for each variable).

problem 9: Given the grammar, with lower case terminals and upper case nonterminals, and S the initial nonterminal

S -> aS | aA | bA
A -> Aa | ABb | cA
B -> bB | bdB | c

a) remove left recursion as needed, showing the modified grammar

b) left-factorize as needed what you get in a), showing the new grammar

c) Is the resulting grammar LL(1)? Argue piece by piece why it is or why it is not, showing all (and only the necessary) First and Follow sets.

problem 10: Assume the following static program structure, show the static chains and display when exactly five ARs are on the stack, assuming procedure A is called first.

proc A
begin /* proc A */
proc B
begin /* proc B */
proc C
begin /* proc C */
call A
end /* proc C */
call C
end /* proc B */
proc D
begin /* proc D */
call B
end /* proc D */
call D
end /* proc A */

Computer Engineering, Engineering

  • Category:- Computer Engineering
  • Reference No.:- M93892

Have any Question? 

Related Questions in Computer Engineering

1 the simplest and most economical way of identifying an

1. The simplest and most economical way of identifying an individual is through a password. What are the conditions that are required to establish password protection and what are some reasons why passwords might not be ...

You may search these questions or part of them on the web

You may search these questions or part of them on the web resource links available under "Additional Web Resources for Telecommunication & Network Security.pdf". If you do so, you must provide the reference to the resour ...

Write a growsquareprinter program that constructs a

Write a GrowSquarePrinter program that constructs a Rectangle object square representing a square with top-left corner (100, 100) and side length 50, prints its location by calling System.out.println(square), applies the ...

1 how is an incident response plan different from a

1. How is an incident response plan different from a disaster recovery plan? 2. What is risk appetite? Explain why risk appetite varies from organization to organization. 3. What is a cost benefit analysis?

1 when an http server receives a request message from an

1. When an HTTP server receives a request message from an HTTP client, how does the server know when all headers have arrived and the body of the message is to follow? 2. In a nonpersistent HTTP connection, how can HTTP ...

1 what are electromycycles most important assets that must

1. What are ElectroMyCycle's most important assets that must be protected with security mechanisms? 2. What are the biggest security risks that ElectroMyCycle faces? 3. Design a high-level security policy for ElectroMyCy ...

Computer class assignmentclass consider your current or

Computer Class Assignment Class, Consider your current or future career (nursing), clubs or volunteer activities or any other occupations where a PowerPoint presentation might be advantageous. Where might you use PowerPo ...

Powerpoint presentationnote the accepted microsoft office

PowerPoint Presentation Note: The accepted Microsoft Office versions for this assignment are Microsoft Office 2013 (for PC) and Microsoft Office for Mac 2011 (for Macintosh). Students may use a more recent version if ava ...

1 why should salts be chosen at random2 does using

1. Why should salts be chosen at random? 2. Does using passwords with salts make attacking a specific account more difficult than using passwords without salts? Explain why or why not. 3. Show that a system using an EKE ...

What are the benefits of web cache and list four of the

What are the benefits of web cache and List four of the principles of the best use of cache?

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen