CSE 222 Lab #1

Objectives

Familiarity with writing code involving Sets.
Exposure to writing code that instantiates a template.
Exposure to writing programs that process text files.
Exposure to some of the problems and techniques associated with writing simple translators.
Exposure to using command-line arguments.
Exposure to using Unix input and output redirection.

The Problem

Web browsers interpret an easy-to-learn markup language (HTML). So one approach to translating routine documents into nicely-formatted ones is to translate them into HTML, inserting markup "tags" as appropriate. For example, if emacs didn't already know how to pretty-print Resolve/C++ files, you might choose to do it yourself by translating Resolve/C++ source files into HTML files containing tags to demarcate keywords, etc. Then to pretty-print the document you could just view the HTML translation in a web browser and print it from there.

This was the task your employer gave to a former employee, Candace B. Rittenoff, who took some bad advice from her tax advisor, Lew Pole, and is now "working" for the IRS. As the new intern hired by the boss, Dave Reckoning, you have inherited Candace's initial design and are to complete the assignment. The program is supposed to read a Resolve/C++ source file from stdin and write to stdout an HTML file which, if viewed using a browser, is ready to be pretty-printed in the sense that:

It appears in a fixed-width font so indenting is the same as in the original Resolve/C++ source file.
Informal comments are in forest green italics, and Resolve/C++ formal comments are in saddle brown italics.
Resolve/C++ keywords (except those in comments) appear in boldface.

An executable version of an acceptable -- yet not necessarily perfect -- solution to the assignment is available in:

/class/sce/now/222/labs/lab01/Lab01/Pretty_Print_Sample

You can see what this solution produces for the source file Hello_World.cpp either by viewing the HTML page source of this file in your browser:

/class/sce/now/222/labs/lab01/Lab01/Hello_World.html

or by opening it in emacs. This will allow you to see what HTML tags are required to get italics, boldface, and colors. Look closely! Observe what happens when the embedded HTML tags are interpreted by a browser, and be careful to notice and understand subtle things that have nothing to do with italics, colors, or boldface text.

Your solution to Lab #1 is designed to be what is called a filter in Unix: it takes input from stdin and writes output to stdout. To use your program, you will want to redirect input from a Resolve/C++ source file and redirect output to an HTML file. For example, to markup the source file Something.cpp, creating the HTML document Something.html, the appropriate Unix command is:

Pretty_Print < Something.cpp > Something.html

Notice that the "<" and ">" in this command are not brackets around "Something.cpp". The "<" is followed by the name of a file from which stdin is to be redirected; the ">" is followed by the name of a file to which stdout is to be redirected. You may redirect either input or output or both, independently, and it doesn't matter in which order you do this. So the following command is equivalent to the above:

Pretty_Print > Something.html < Something.cpp

Notice also that if you redirect output to a file then the file should not already exist, or you get an error message. You can overcome this either by explicitly removing that file before executing the above command, or by using ">!" in place of ">" for output redirection. The following command, then, effectively removes the file Something.html if it exists, and then redirects output to it:

Pretty_Print < Something.cpp >! Something.html

Method

Here's what to do:

Copy the initial lab #1 files to your own working directory and get into that directory:
```
cp -R /class/sce/now/222/labs/lab01/Lab01/ .
```
```
cd Lab01
```
Get into an emacs window and visit your Lab01 directory. You should see a file called Pretty_Print.cpp. The basic structure of the program, including specifications for global operations whose bodies you should write, is provided for you courtesy of Candace. Study the skeleton code and the specifications provided. Then complete the parts designated by Dave "for students to fill in".
When you are satisfied that your program works, get into your Lab01 directory in an xterm window and use the submit command to submit your solution as follows (noting that you will need to use the appropriate suffix in place of ?? in this command, as posted next to your instructor's name on the CSE 222 Home Page):
```
submit c222?? lab1 Pretty_Print.cpp
```
If you get an error message rather than a confirmation of success, please read the message; it contains useful information! Do not just run the same command again. Save the e-mail you get as a receipt of submission, just in case.

Possible Maintenance Activities

Here are some questions about possible maintenance activities involving this program:

How does your program work on nested comments? For example, suppose you are inside a comment and find a /* or // beginning-of-comment indicator. What is "the right thing" for the program to do? (You'll probably have to look this up in a C++ book unless you're a C++ guru, because it's not clear which such programs should be legal C++ programs in the first place.)
Run the program with its own source code as input. Does it (appear to) work properly?
What are some of the reasons the program might be slow?
You could use a Sequence in place of a Set as the repository of keywords. Would this complicate the program or simplify it? Can you predict how this change might affect performance?
The list of keywords is in a file, so the part of the program that selects keywords and marks them to appear in boldface is not really specifically designed for Resolve/C++ programs. What other uses might it have?

Any extra work is strictly optional, for your own benefit, and will not directly affect your grade.