Project #2 Solution

1. Specification




Design, write and test a program that accepts an arithmetic expression of unsigned integers in postfix notation in which the tokens are separated by spaces and builds and processes the arithmetic expression tree that represents that expression.




The main class will be P2GUI. It should create a Swing based GUI shown below:










The GUI must be generated by code that you write. You may not use a drag-and-drop GUI generator.




Pressing the Construct Tree button should cause the following: (i) the arithmetic expression tree that represents the entered postfix expression will be constructed, (ii) using that tree, the corresponding fully parenthesized infix expression should be generated and displayed in the GUI and finally (iii) a file should be generated that contains the 3-address format instructions corresponding to the arithmetic expression. These topics, including relevant classes for implementing and processing an expression tree, are discussed in the week 4 reading “Binary Trees, Expression Trees, BST (AVL) trees, and B-Trees” section II “Expression Trees”.




The above example should produce the following output file containing the 3-address instructions:




Add R0 5 9

Sub R1 3 R0

Mul R2 2 3

Div R3 R1 R2




It is not necessary to reuse registers within an expression as shown in the above mentioned reading and you can assume there are as many available as needed. Each new expression should, however, begin using registers starting at R0.




You may assume that the expression is syntactically correct with regard to the order of operators and operands, but you should check for invalid tokens, such as characters that are not valid operators or operands such as 2a, which are not valid integers. If an invalid token is detected, a checked custom exception InvalidTokenException should be thrown and caught by the main class and an appropriate error message should be displayed. Below is an example:




Your program should compile without errors.




The Google recommended Java style guide (https://google.github.io/styleguide/javaguide.html) should be used to format and document your code. Specifically, the following style guide attributes should be addressed: header comments include filename, author, date and brief purpose of the program; In-line comments used to describe major functionality of the code; the meaning and the role of variables and constants are indicated as code comments; meaningful variable names and prompts applied; class names are written in UpperCamelCase; variable names are written in lowerCamelCase; constant names are in written in All Capitals; braces use K&R style.




In addition the following design constraints should be followed: declare all instance variables private; avoid the duplication of code.




2. Submission requirements




Submit the following to the Project 2 assignment area no later than the due date listed in your LEO classroom.




All .java source files (no other file types should be submitted) and the output file generated by the program. The source code should use Java code conventions and appropriate code layout (white space management and indents) and comments. All submitted files may be included in a .zip file.



The solution description document P2SolutionDescription (.pdf or .doc / .docx) containing the following:
(1) Assumptions, main design decisions, error handling;




(2) A UML class diagram that includes all classes you wrote. Do not include predefined classes. You need only include the class name for each individual class, not the variables or methods;




(3) A table of test cases including the test cases that you have created to test the program. The table should have 5 columns indicating (i) what aspect is tested, (ii) the input values, (iii) the expected output, (iv) the actual output and (v) if the test case passed or failed. Each test case will be defined in a table row.




(4) Relevant screenshots of program execution;

(5) Lessons learned from the project;




Grading Rubric:






Criteria


Meets
Does Not Meet






5 points
0 points
















GUI is hand coded and matches required
GUI is generated by a GUI generator or






design
does not match required design






Other classes are used to support the
Does not use other classes to support the


Design


implementation of the arithmetic expression
implementation of the arithmetic






tree
expression tree






All instance data is private
Some instance data is not private






Uses good object-oriented design practice
Does not use good object-oriented design






regarding code efficiency, encapsulation and
practice regarding code efficiency,






information hiding, class and code reuse,
encapsulation and information hiding,






high cohesion of classes, avoiding code
class and code reuse, high cohesion of






duplication.
classes, avoiding code duplication.






10 points
0 points
















Produces correct fully parenthesized infix
Does not produce correct fully






expressions for all input
parenthesized infix expressions for some








input


Functionality


Produces correct three address file for all
Does not produce correct three address






input
file for some input






Correctly parses expressions with space
Does not correctly parse expressions with






delimiters
space delimiters






Registers restart at R0 on each new
Registers do not restart at R0 on each






expression
new expression






Detects and handles invalid tokens
Does not detect and handle invalid tokens






5 points
0 points
















Test cases table is defined and included in
Test cases table is not defined and






the P2SolutionDescription document
included in the P2SolutionDescription








document






All operators included in test cases
Some operators not included in test cases


Test Cases


Test cases include expressions with and
Test cases don't include expressions with






without spaces
and without spaces






Test cases include a case to test invalid
Test cases do not include a case to test






token beginning with a digit
invalid token beginning with a digit






Test cases include a case to test invalid
Test cases do not include a case to test






operators
invalid operators






5 points
0 points
















Solution description document
No solution description document is


Documentation


P2SolutionDescription includes all the
included






required sections (appropriate titled).








Source code follows Google
Source code does not follow Google






recommendation Java style
recommendation Java style






Comment blocks with class description
Comment blocks with class description






included with each class
not included with each class






Source code is commented and indented
Source code is not commented and








indented












Overall Score


Meets
Does not meet






16 or more
15 or less