CS 50200 - Programming Assignment 2

This assignment makes use of the files contained in this zip file. This assignment is due Tuesday, February 11.

This assignment is based on Language_3. This is not a difficult assignment. It is meant to help you familiarize yourself with the interpreter code for Language_3

In the zip file there is a file Language_3a.txt that describes a new language called Language_3a. Language_3a adds four new operators to Language_3. Your assignment is to add code to the interpreter for Language_3 so that the new interpreter can handle the new operators.

In the zip file there is the file Evaluate_3a.java. As distributed, this file is the interpreter for Language_3. Modify this file so that it handles the four new operators described in Language_3a.txt.

Also in the zip file there is the file AST2infix_3a.java. As distributed, this file converts Language_3 into infix form. Modify this file so that it handles the four new operators. The infix notation for these operators should be exactly like their C/C++/Java counterparts.

In the zip file there is a prettyprinter for trees, PrettyPrinter.java. But this prettyprinter is very verbose. Write a prettyprinter, called PrettyPrinter2.java, that does the following.

1. It puts the left node "inline" with the root.
2. It handles the special case when depth=1 by putting everything inline with the root.
3. It handles the special case when depth=2 by putting everything inline with the root.
4. All consecutive closing parentheses are at the end of a line.

In the zip file there is an example output file for Language_3, Language_3_Examples_output.txt. Look at that file to get a good idea of what the prettyprinter should produce.

When you have finished implementing Evaluate_3a.java, AST2infix_3a.java, and PrettyPrinter2.java, then the file Language_3a_Examples.java should compile and run. The output from running this program should look exactly like the file Language_3a_Examples_output.txt. Also, make sure that you didn't break anything from Language_3. The program Language_3_Examples.java from the zip file should also compile and run correctly and the program's output should look exactly like the file Language_3_Examples_output.txt (every Language_3 expression is also a valid Language_3a expression).

Turn in a zip file called CS502Hw2Surname.zip (where Surname is your last name) containing your versions of Evaluate_3a.java, AST2infix_3a.java, and PrettyPrinter2.java (just those files).

This assignment is due Tuesday, February 11.