Sonoma State University
Department of Computer Science
CS-460: Programming Languages
Exercise 1a: Regular Expressions

Objective

In a team of three or four students, define a regular expression that matches ANSI/ISO C99 C-style comments as well as the text between the comments. I will supply paper for each group of students to create a deterministic finite state machine (DFA) diagram. What should the deterministic finite state machine (DFA) look like?

• A non-final state should be represented by a single circle with a non-negative integer inside the circle.
• A final-state should be represented by two circles (one circle encapsulating a second circle) with a non-negative integer inside the inner circle.
• Each state (non-final or final) should use a unique non-negative integer that is not used for any other state in a given DFA.
• State transitions should be represented by arrows pointing from one state to another state. State transitions should include the byte which triggers the transition.
• I will provide examples during class.

What does an ANSI/ISO C99 comments look like?

Block-style C comments:

• A block-style C comment begins with a forward-slash followed by an asterisk: /*
• A block-style C comment ends with an asterisk followed by a forward-slash: */
• Any text in-between the beginning of a C block-style comment and the ending of the C-block style comment is ignored. A block-style comment can span multiple lines.
• Example: /* This is a comment */

C++ style comment:

• A C++ style begins with forward-slash forward-slash: //
• Everything after the forward-slash forward slash is ignored up until a line feed byte is encountered (typically denoted as backslash-n or \n)
• The comment is terminated at the line feed byte.
• Example: // This is a comment

Submission Instructions:

On the sheet of paper, please write the names of each student in the group along with "Exercise 1a: Regular Expressions" then using an Android smartphone, iPhone, tablet, webcam, or digital camera take a digital photo of the completed diagram and upload to Canvas. I will collect the paper answers as well.

Exercise 1a Rubric

CRITERIA	RATINGS		POINTS
Deterministic Finite State Machine diagram	Proficient 10 points A partial or complete Deterministic Finite State Machine machine diagram is submitted which is relevant to detecting opening and/or closing C-style block comments and/or C++ style line comments.	Below Expectation 0 points No solution submitted.	10 points
Total points: 10