Concepts of Programming Languages ---- Chapter 14 Exception Handling and Event Handling
Name : Fandy Limardi
NIM : 1601210713
Lecture : Tri Djoko Wahjono, Ir., M.Sc. (D0206)
Assignment : Concept of programming languages ---- Chapter 14 Exception Handling and Event Handling
Review Question
1. Define
functional form, simple list, bound
variable, and referential transparency.
A higher-order function, or
functional form, is one that either takes one or more functions as parameters
or yields a function as its result, or both. A simple list is the problem of
membership of a given atom in a given list that does not include sublists. A
bound variable is a variable that never changes in the expression after being
bound to an actual parameter value at the time evaluation of the lambda
expression begins. A referential transparency is the execution of a function
always produces the same result when given the same parameters
2. When is an exception
thrown or raised?
An exception is raised when its associated event occurs.
6. Explain in which the arithmetic processing
capabilities of LISP and Prolog are similar.
Arithmetic processing is simple to
implement in LISP and Prolog.
7. What
does the abbreviation REPL stand for?
REPL stand for
read-evaluate-print loop
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:
There are four exceptions that are defined in the default package, Standard:
·
Constraint_Error
·
Program_Error
·
Storage_Error
·
Tasking_Error
11. are they any predefined exceptions in Ada?
Yes,
they are.
14. What
is the name of all C++ exception handlers?
Try
clause.
16. Which standard libraries
define and throw the exception overflow_error in C++?
The
exception overflow_error is thrown by math library functions.
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.
33. What is the purpose of a Java JFrame?
The JFrame class defines the data and methods that
are needed for frames. So, a class that uses a frame can be a subclass of
JFrame. A JFrame has several layers, called panes.
34. What are the different forms of assert statement?
There
are two possible forms of the assert statement:
·
assert
condition;
·
assert
condition : expression;
Problem Set
1. What mechanism did early programming languages provide to detect
or attempt to deal with errors?
Early programming languages were designed and
implemented in such a way that the user program could neither detect nor
attempt to deal with such errors. In these languages, the occurrence of such an
error simply causes the program to be terminated and control to be transferred
to the operating system.
2. Describe the approach for the detection of subscript range errors
used in C and Java.
In C subscript ranges are not checked. Java
compilers usually generate code to check the correctness of every subscript
expression. If any exception generates, then an unchecked exception is thrown.
6. In languages without exception-handling facilities, it is common
to have most subprograms include an “error” parameter, which can be set to some
value representing “OK” or some other value representing “error in procedure”.
What advantage does a linguistic exception-handling facility like that of Ada
have over this method?
There are several advantages of a linguistic
mechanism for handling exceptions, such as that found in Ada, over simply using
a flag error parameter in all subprograms. One advantage is that the code to
test the flag after every call is eliminated. Such testing makes programs
longer and harder to read. Another advantage is that exceptions can be
propagated farther than one level of control in a uniform and implicit way.
Finally, there is the advantage that all programs use a uniform method for
dealing with unusual circumstances, leading to enhanced readability.
7. In languages without exception-handling facilities, we could send
an error-handling procedure as parameter to each procedure that can detect
errors than must be handled. What disadvantage are there to this method?
There are several disadvantages of sending error
handling subprograms to other subprograms. One is that it may be necessary to
send several error handlers to some subprograms, greatly complicating both the
writing and execution of calls. Another is that there is no method of
propagating exceptions, meaning that they must all be handled locally. This
complicates exception handling, because it requires more attention to handling
in more places.
