.Open CS320/05 Questions UML Semantics
. Using the UML
We will be using the UML in notes, projects, labs, and final questions. It
is perfect for describing:(1) the structure of a language, (2) the internal
data structures used in compilers and interpreters, and (3) the meaning of
each part of the language. In any session or anywhere in the final I may 
ask you to draw and/or interpret diagrams using the UML. Here is a question
on semantics that I ask on finals:
	Give an example of how your project team described the 
semantics of its language.

. Question 1a Model of Work in this class
Draw a UML diagram of the following classes and associations. Do not show 
any operations or attributes! Use the following class names: Student, 
PieceOfWork, Date, SequenceNumber, TypeOfWork. Relationships: Each student
does several pieces of work. Each piece of work is done by one student on a
particular date. Each piece of work is of a particular type. Each piece of
work has a sequence number.
. Question 1b
Add multiplicities and some role names to your diagram. Suggested role 
names: does, doneBy, etc..

Answer:
.See ./05a.html

In the following work as a group of 4-6 people. When you have a solution 
(or 2) wait for a chance to present the diagrams to the class.

. Question 2a Model of the Java 1.0 AWT Class Library
Draw a UML diagram of the following classes and relationships (Note. these
are taken from the Java library of classes): Integer and Float are 
sub-types of Object. All Applets are Panels, all Panels are Containers, all
Containers are Components, and all Components are Objects. Some other 
Components are Buttons, Lists, and TextFields.

Answer:
.See ./05a.html
. Question 2b
What do you add to the previous model
to show that:
	 a Container can have any number of Components inside it?

. Question 3a Compositions
Draw a UML diagram that uses composition (not attributes) to model the 
following C++ class:
.As_is 	class Wodget { public: float size; int knobs; string id; };

Answer:
.See ./05a.html
. Question 3b
Draw a UML diagram that uses attributes (not composition) to model the C++
Wodget class above.

Answer:
.See ./05a.html

. Question 4 Lab work/Web site
Draw a UML diagram of the part of your web site that is concerned with this
class. Include the following ideas: Your_Home_Page, Your_CS320_Page, 
Lab_Page, Source_Code_Page.

Answer:
.See ./05a.html
. Question 5 LISP Data
Draw a UML diagram of a Node where: A Node is either Empty, an Atom, or a 
Pair. Each Pair has two pointers to nodes called the car and cdr of the 
Pair.


Answer:
.See ./05a.html

. Question 6 Syntax and Semantics
Which diagram (1,2,3) matches best each XBNF definition (alpha, beta, gamma)
in this
.See ./05xab.png
diagram.

. Question 6a Syntax
For each syntax in
.See ./05xab.png
give a string of "a"s and "b"s that fit that syntax and see if
it also fits the other two.  Which syntax is most general -- every string
that fits the other two must also fit it.

.Open Question 7 MiniCalc Syntax and Semantics
MiniCalc is a program that accepts simple expressions typed in by the
user and evaluates them.

MiniCalc uses simple integer Expressions:
       Expression ::= $Constant | $Operation. All expressions can be
evaluated  and return an Int as a value.
.As_is 		123
.As_is 		1+2

	Constant ::= digit #digit. The evaluation of a constant 
returns its value. (This was defined in an earlier session).
.As_is 		123
	evaluate("123") = 123.

	Operation::= $Constant $Operator $Expression. First the 
Expression is evaluated and then the Constant.
.As_is 		1+2

	The Operator is applied to these values to
calculate the value of the Operation.

	Operator ::= "+" | "-" | "*" | "/".
.As_is 		+
	Each operator has an `apply` function that takes two values 
and returns a value.
.As_is 		apply(left:Int, right:Int): Int

Draw a diagram, using the UML, that describes the classes of objects
(Expression, Constant, Operation, Operator) plus 
their semantics. Do not show any syntax!

Answer:
.See ./05a.html
.Close

. OO Classroom Activity
To Be Announced: Given the UML description of .... students are asked to 
simulate various the objects collaborating.
. Answers
.See http://www/dick/cs320/05a.html
. Review
Think back over this class and grade your personal performance in terms
of how much work you need to do on this topic before the final.
.Close