Tuesday, June 25, 2013

Concepts of Programming Languages 10th Edition : Chapter 16

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

REVIEW QUESTIONS

1. What are three primary uses of symbolic logic in formal logic?
   => - to express propositions
- to express the relationships between propositions, and
- to describe how new propositions can be inferred from other propositions that are assumed to be true.

2. What are the two parts of a compound term?
   => Two parts of a compound term are:  a functor, which is the function symbol that names the relation, and an ordered list of parameters, which together represent an element of the relation.

3. What are the two modes in which a proposition can be stated?
   => Propositions can be stated in two modes: one in which the proposition is defined to be true, and one in which the truth of the proposition is something that is to be determined. In other words, propositions can be stated to be facts or queries.

5. What are antecedents? Consequents?
   => Antecedents are the right side of clausal form propositions, whereas Consequents are the left side of clausal form propositions, because it is the consequence of the truth of the antecedent.

Concepts of Programming Languages 10th Edition : Chapter 15

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

REVIEW QUESTION

2. What does a lambda expression specify?
   => The predicate function is often given as a lambda expression, which in ML is defined exactly like a function, except with the fn reserved word, instead of fun, and of course the lambda expression is nameless.

5. Explain why QUOTE is needed for a parameter that is a data list.
   => To avoid evaluating a parameter, it is first given as a parameter to the primitive function QUOTE, which simply returns it without change.

6. What is a simple list?
   => A list which membership of a given atom in a given list that does not include sublists.

7. What does the abbreviation REPL stand for?
   =>REPL stand for read-evaluate-print loop.

11. What are the two forms of DEFINE?
    => The simplest form of DEFINE is one used to bind a name to the value of an expression. This form is (DEFINE symbol expression) The general form of such a DEFINE is (DEFINE (function_name parameters) (expression)

Concepts of Programming Languages 10th Edition : Chapter 14

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

REVIEW QUESTION

6. What is exception propagation in Ada?
   => Exception propagation allows an exception raised in one program unit to be handled in some other unit in its dynamic or static ancestry. This allows a single exception handler to be used for any number of different program units. This reuse can result in significant savings in development cost, program size, and program complexity.

9. What is the scope of exception handlers in Ada?
   => Exception handlers can be included in blocks or in the bodies of subprograms, packages, or tasks.

10. What are the four exceptions defined in the Standard package of Ada?
    => There are four exceptions that are defined in the default package, Standard:
- Constraint_aError
- Program_Error
- Storage_Error
- Tasking_Error
11. Are they any predefined exceptions in Ada?
    => Yes, they are.

12. What is the use of Suppress pragma in Ada?
    => The suppress pragma is used to disable certain run-time checks that are parts of the built-in exceptions in Ada.

14. What is the name of all C++ exception handlers?
    => Try clause.

30. In which version were assertions added to Java?
    => Assertions were added to Java in version 1.4.

31. What is the use of the assert statement?
    => The assert statement is used for defensive programming. A program may be written with many assert statements, which ensure that the program’s computation is on track to produce correct results.

32. What is event-driven programming?
    => Event-driven programming is a programming where parts of the program are executed at completely unpredictable times, often triggered by user interactions with the executing program.

Concepts of Programming Languages 10th Edition : Chapter 13

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

REVIEW QUESTION

1. What are the three possible levels of concurrency in programs?
   => - Instruction level (executing two or more machine instructions simultaneously)
        - Statement level (executing two or more high-level language statements simultaneously)
        - Unit level (executing two or more subprogram units simultaneously)

7. What is the difference between physical and logical concurrency?
   => Physical concurrency is several program units from the same program that literally execute simultaneously. Logical concurrency is multiple processors providing actual concurrency, when in fact the actual execution of programs is taking place in interleaved fashion on a single processor.

8. What is the work of a scheduler?
   => Scheduler manages the sharing of processors among the tasks.

12. What is a heavyweight task? What is a lightweight task?
    => Heavyweight task executes in its own address space. Lightweight task all run in the same address space.

Concepts of Programming Languages 10th Edition : Chapter 12



Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

REVIEW QUESTION

2. What are the problems associated with programming using abstract data types?
   => -In nearly all cases, the features and capabilities of the existing type are not quite right for the new use.
      -The type definitions are all independent and are at the same level.

4. What is message protocol?
   => Message protocol is the entire collection of methods of an object.

5. What is an overriding method?
   => Overriding method is method that overrides the inherited method.

7. What is dynamic dispatch?
   => Dynamic dispatch is the third characteristic (after abstract data types and inheritance) of object-oriented programming language which is a kind of polymorhphism provided by the dynamic binding of messages to method definitions.

Concepts of Programming Languages 10th Edition : Chapter 11

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

Review Question

1. What are three primary uses of symbolic logic in formal logic?
   => - to express propositions
- to express the relationships between propositions, and
- to describe how new propositions can be inferred from other propositions that are assumed to be true.

2. What are the two parts of a compound term?
   => Two parts of a compound term are:  a functor, which is the function symbol that names the relation, and an ordered list of parameters, which together represent an element of the relation.

3. What are the two modes in which a proposition can be stated?
   => Propositions can be stated in two modes: one in which the proposition is defined to be true, and one in which the truth of the proposition is something that is to be determined. In other words, propositions can be stated to be facts or queries.

5. What are antecedents? Consequents?
   => Antecedents are the right side of clausal form propositions, whereas Consequents are the left side of clausal form propositions, because it is the consequence of the truth of the antecedent.

7. What are the forms of Horn clauses?
   => Horn clauses can be in only two forms: They have either a single atomic proposition on the left side or an empty left side. The left side of a clausal form proposition is sometimes called the head, and Horn clauses with left sides are called headed Horn clauses. Headed Horn clauses are used to state relationships, such as likes( bob, trout ) likes( bob, fish ) x fish( trout )

11. What is an uninstantiated variable?
    => An uninstantiated variable is a variable that has not been assigned a value.

13. What is a conjunction?
    => Conjunctions contain multiple terms that are separated by logical AND operations.

PROBLEM SET

1.”All predicate calculus propositions can be algorithmically converted to clausal form”. Is this statement true or false?
   => This statement is true. Nilsson (1971) gives proof that this can be done, as well as a simple conversion algorithm for doing it.

2. Describe how a logic programming language is different from a general programming language.
   => Programming that uses a form of symbolic logic as a programming language, unlike other general programming language, is often called logic programming; languages based on symbolic logic are called logic programming languages, or declarative languages.

10. Using the internet for reference, find some of the applications of expert systems.
    => - Expert system in healthcare: The Electronic health record (EHR) is designed to replace the traditional medical and bring together a more versatile, expansive and robust expert system to provide greater quality care.
       - Expert systems in the financial field: Loan departments are interested in expert systems for morgages because of the growing cost of labour, which makes the handling and acceptance of relatively small loans less profitable.

       - A new application for expert systems is automated computer program generation. Funded by a US Air Force grant, an expert system-based application (hprcARCHITECT) that generates computer programs for mixed processor technology (FPGA/GPU/Multicore) systems without a need for technical specialists has recently been commercially introduced.

Monday, June 24, 2013

Concepts of Programming Languages 10th Edition : Chapter 10

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

Review Question

2. Which of the caller or callee saves execution status information?
   => Called.

4. What is the task of a linker?
   => The task of a linker is to find the files that contain the translated subprograms referenced in that program and load them into memory.

6. What is the difference between an activation record and an activation record instance?
   => An activation record is the format, or layout, of the moncode part of a subprogram, whereas an activation record instance is a concrete example of an activation record, a collection of data in the form of an activation record.

8. What kind of machines often use registers to pass parameters?
   => RISC.

11. What is an EP, and what is its purpose?
    => EP is a point or first address of the activation record instance of the main program. It is required to control the execution of a subprogram.


Problem Set

6. Although local variables in Java methods are dynamically allocated at the beginning of each activation,
   under what circumstances could the value of a local variable in a particular activation retain the value of
   the previous activation?
   => If the variable is declared as static. Static modifier is a modifier that makes a variable history – sensitive.

8. Pascal allows gotos with nonlocal targets. How could such statements be handled if static chains were used for nonlocal variable access? Hint:Consider the way the correct activation record instance of the static parent of a newly enacted procedure is found(see Section 10.4.2).
   =>  Following the hint stated with the question, the target of every goto in a program could be represented as an address and a nesting_depth, where the nesting_depth is the difference between the nesting level of the procedure that contains the goto and that of the procedure containing the target. Then, when a goto is executed, the static chain is followed by the number of links indicated in the nesting_depth of the goto target. The stack top pointer is reset to the top of the activation record at the end of the chain.

9. The static-chain method could be expanded slightly by using two static links in each activation  record instance where the  second points to the static grandparent activation record instance. How would this approach affect the time required for subprogram linkage and nonlocal references?
   =>  Including two static links would reduce the access time to nonlocals that are defined in scopes two steps away to be equal to that for nonlocals that are one step away. Overall, because most nonlocal references are relatively close, this could significantly increase the execution efficiency of many programs.

Concepts of Programming Languages 10th Edition : Chapter 9

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

Review Questions

1. What are the three general characteristics of subprograms?
   => - Each subprogram has a single entry point.
      - The calling program unit is suspended during the execution of the called subprogram, which implies that there is only subprogram in execution at any given time.
      - Control always returns to the caller when the subprogram execution terminates.

8. What are formal parameters? What are actual parameters?
   => Formal parameters are the parameters in the subprogram header, whereas actual parameters are a list of parameters to be bound to the formal parameters of the subprogram.

10. What are the differences between a function and a procedure?
    => Functions structurally resemble procedures bu are semantically modeled on mathematical function.

11. What are the design issues for subprograms?
    => The design issues for subprograms are:
- Are local variables statically or dynamically allocated?
- Can subprogram definitions appear in other subprogram definitions?
- What parameter-passing method or methods are used?

24. What is an overloaded subprogram?
    => An overloaded subprogram is one that has the same name as another subprogram in the same referencing environment.

25. What is ad hoc binding?
    => The environment of the call statement that passed the subprogram as an actual parameter is called ad hoc binding.

26. What is multicast delegate?
    => Multicast delegate is the all of the methods stored in a delegate instance are calles in the order in which they were placed in the instance.

32. What exactly is a delegate?
    => Delegate is a power and flexibility of method pointers which is increased by making them objects.

34. What is a closure?
    => Closure is a nested subprogram to be called from anywhere in a program.



Problem Set

3. Argue in support of the templated functions of C++. How is it different from the templated functions of other languages?
   => It is different as C++ differentiates function based on overloading. It is not practical to make multiple function overloading in regard to writability and readability. Instead, creating a template allows a function to receive any datatype as long as the variation is based on the formal parameter definition.

5. Consider the following program written in C syntax:
void swap(int a, int b) {
int temp;
temp = a;
a = b;
b = temp;
}

void main() {
int value =1, list[5]= {2,4,6,8,10};
swap (value,list[0]);
swap(list[0],list[1]);
swap(value,list[value]);
}
   for each of the following parameter-passing methods, what are all of the values of the variables value, and list after each of the three calls to swap?
a. Passed by value
b. Passed by reference
c. Passed by value-result

   => a. Passed by Value
          -value =1 , list[5] = {2,4,6,8,10}
         b. Passed by reference
         -value =6, list[5] ={4,1,2,8,10}
         c. Passed by value-result
         -value =6, list[5] ={4,1,2,8,10}

7. Consider the following program written in C syntax:
void fun(int first, int second){
first+=first;
second+=second;
}

void main(){
int list[2] ={3,5};
fun(list[0],list[1]);
}
   for each of the following parameter-passing methods, what are the values of the list array after execution?
a. Passed by value
b. Passed by reference
c. Passed by value-result

   =>   a. 3, 5
  b. 6, 10
  c. 6, 10

15. How is the problem of passing multidimensional arrays handled by Ada?

    => Ada compilers are able to determine the defined size of the dimensions of all arrays that are used as parameters at the time subprograms are compiled.

Concepts of Programming Languages 10th Edition : Chapter 8

Created By : Robert W. Sebesta
Lecturer : Mr. Tri Djoko Wahjono, Ir. M.Sc
Answered by : Shirley Halim Ng
NIM : 1601233805
Class : 02PCT

Review Questions

1. What is the definition of control structure?
   => A control structure is a control statement and the collection of statements whose execution it controls.

3. What is the definition of block?
   => A block is a sequence of code, delimited by either braces or the do and end reserved words.

5. What are the design issues for selection structures?
   => The design issues for selection structures are :
- What is the form and the type of the expression that controls the selection?
- How are the then and else clauses specified?
- How should the meaning of nested selectors be specified?

9. What are the design issues for multiple-selection statements?
   => The design issues for multiple-selection statements are:
- What is the form and type of the expression that controls the selection?
- How are the selectable segments specified?
- Is execution flow through the structure restricted to include just a single selectable segment?
- How are the case values specified?
- How should unrepresented selector expression values be handles, if at all?

15. What are design issues for counter-controlled loop statements?
    => The design issues for counter-controlled loop statements are:
- What are the type and scope of the loop variable?
- Should it be legal for the loop variable or loop parameters to be changed in the loop, and if so, does the change affect loop control?
- Should the loop parameters be evaluated only once, or once for every iteration?

19. What does the range function in Phyton do?
    => Range function in Phyton takes one, two, or three parameters and it never returns the highest value in a given parameter range.

20. What contemporary languages do not include a goto?
    => Ruby

26. What is a user-defined iteration control?
    => A user-defined iteration control is a primary iteration that an alternative form that is in class by itself.



Problem Set

1. What design issues should be considered for two-way selection statements?
   =>The design issues for two-way selectors can be summarized as follows:

      - What is the form and type of the expression that controls the selection?

      - How are the then and else clauses specified?

      - How should the meaning of nested selectors be specified?

11. Explain the advantages and disadvantages of the Java switch statement, compared to C++'s switch statement.
    => The Java variable in the argument of a switch statement can be of type integral ( byte, short etc.), char and String( JDK 1.7 onwards), whereas in C++ the argument can be int or char.

14. State one of the main legitimate needs for gotos.
    => It is useful for programmer who wants to check errors in their program. Rather than fully modifying their code, they can put some goto statement inside the if statement and return the value of the error in case if an error happens.