Sonoma State University
Department of Computer Science
CS-460: Programming Languages
Programming Assignment 1: Ignore comments

Objective:

• Write a program in C or C++ that will identify and remove comments from an input test file.
• Your program should utilize a procedurally-driven deterministic finite state automoton (DFA) to identify comments. Table-driven DFA solutions will have reduced scores (per the grading rubric) since such solutions are typically automatically generated by compiler tools such as Yacc, Lex, Bison, etc.

Please note:

• The input test files (below) conform to our C-like programming language defined in Backus-Naur Form (BNF) with two exceptions: programming_assignment_1-test_file_5.c and programming_assignment_1-test_file_6.c contain partial C block-style comments that are unterminated. Therefore, I expect your program to output an error message along with the correct line number where the offending comment is. For example, "ERROR: Program contains C-style, unterminated comment on line 3".

There are two types of comments your program should remove:

• C block-style comments: /* Everything inside this space is a comment! */
• C++ style line comments: // This comment will be ignored until a newline (\n) is reached.

Tips and Hints:

• When replacing C++ style line comments, replace the // and all characters up-to (but not including) the newline character (\n) with whitespace. By doing so, you preserve the line numbering of the original input program.
• When replacing C block style comments, replace the /* and all characters up-to */ inclusive with whitespace. This too preserves the line numbering of the original input program.
• One of the subtle advantages to replacing comments with whitespace: line counts are unchanged compared to the original input file. This becomes important when displaying error messages. If you completely delete a comment rather than substituting whitespace, the resulting program's line numbering may change. It is much more desireable to output the correct line number from the original input file when syntax errors occur. Displaying the correct line number where syntax errors occur will be important in later programming assignments when parsing is involved.

I will be using the following files as input to test your program's ability to remove comments:

• programming_assignment_1-test_file_1.c
• programming_assignment_1-test_file_2.c
• programming_assignment_1-test_file_3.c
• programming_assignment_1-test_file_4.c
• programming_assignment_1-test_file_5.c
• programming_assignment_1-test_file_6.c

If you replace comments with whitespace, your program's output should look like this:

• Input file programming_assignment_1-test_file_1.c should output programming_assignment_1-test_file_1-comments_replaced_with_whitespace.c
• Input file programming_assignment_1-test_file_2.c should output programming_assignment_1-test_file_2-comments_replaced_with_whitespace.c
• Input file programming_assignment_1-test_file_3.c should output programming_assignment_1-test_file_3-comments_replaced_with_whitespace.c
• Input file programming_assignment_1-test_file_4.c should output programming_assignment_1-test_file_4-comments_replaced_with_whitespace.c
• Input file programming_assignment_1-test_file_5.c contains an incomplete C block-style comment. Therefore, your program should output "ERROR: Program contains C-style, unterminated comment on line 7".
• Input file programming_assignment_1-test_file_6.c contains an incomplete C block-style comment. Therefore, your program should output "ERROR: Program contains C-style, unterminated comment on line 7".

Uploading your programming project files

• Please upload your source code and a Makefile as a zip or gzipped-tar file.

Programming Assignment 1 Rubric

CRITERIA	RATINGS			POINTS
Compilation: Will the program compile with GNU compiler?	Proficient 2 points Makefile provided. Student's assignment one program is written in C or C++ and compiles with gcc (GNU C compiler) or g++ (GNU C++ compiler) without syntax errors on GNU/Linux. No external libraries (besides standard built-in C/C++ libraries) are required to build the project.	Satisfactory 1 point Student's assignment one program is written in C or C++ and compiles on GNU/Linux with gcc or g++. A Makefile is not included. Extra external library dependencies may be required to compile and run student's assignment one program besides standard built-in C/C++ libraries.	Below Expectation 0 points Makefile not included. Student's assignment one program fails to compile with gcc or g++ on GNU/Linux.	2 points
Parsing Implementation: How was the parsing technique implemented?	Proficient 2 points Student's assignment one program features a procedurally-driven deterministic finite-state automaton (DFA) to identify and parse comments.		Below Expectation 0 points Student's assignment one program implements a table-driven DFA; OR student's assignment one program implements a combination of procedurally-driven and table-driven DFA; OR student's assignment one program fails to use a DFA (table or procedural).	2 points
Test program 1: The first benchmark test.	Proficient 1 point Student's assignment one program removes all comments for test program one without impacting the line numbering of statements. Program line numbering is unaffected by removal of comments.	Satisfactory 0.75 points Student's assignment one program removes all comments. The removal of comments changes line numbering of statements.	Below Expectation 0 points Student's assignment one program does not properly remove all comments. This may be because student's assignment one program failed to compile, was an incomplete solution, or contained logic errors.	1 point
Test program 2: The second benchmark test.	Proficient 1 point Student's assignment one program removes all comments for test program two without impacting the line numbering of statements. Program line numbering is unaffected by removal of comments.	Satisfactory 0.75 points Student's assignment one program removes all comments. Removal of comments changes line numbering of statements.	Below Expectation 0 points Student's assignment one program does not properly remove all comments. This may be because student's assignment one program failed to compile, was an incomplete solution, or contained logic errors.	1 point
Test program 3: The third benchmark test.	Proficient 1 point Student's assignment one program removes all comments for test program three without impacting the line numbering of statements. Program line numbering is unaffected by removal of comments.	Satisfactory 0.75 points Student's assignment one program removes all comments. Removal of comments changes line numbering of statements.	Below Expectation 0 points Student's assignment one program does not properly remove all comments. This may be because student's assignment one program failed to compile, was an incomplete solution, or contained logic errors.	1 point
Test program 4: The fourth benchmark test.	Proficient 1 point Student's assignment one program removes all comments for test program four without impacting the line numbering of statements. Program line numbering is unaffected by removal of comments.	Satisfactory 0.75 points Student's assignment one program removes all comments. Removal of comments changes line numbering of statements.	Below Expectation 0 points Student's assignment one program does not properly remove all comments. This may be because student's assignment one program failed to compile, was an incomplete solution, or contained logic errors.	1 point
Test program 5: The fifth benchmark test.	Proficient 1 point Student's assignment one program detects an unterminated C-style block comment then outputs the error message "ERROR: Program contains C-style, unterminated comment on line 7".	Satisfactory 0.75 points Student's assignment one program outputs a syntax error but the line number where the error occurred is incorrect OR the line number is not identified.	Below Expectation 0 points Student's assignment one program does not detect a syntax error or fails to output a syntax error message. This may be because student's assignment one program failed to compile or was an incomplete solution.	1 point
Test program 6: The sixth benchmark test.	Proficient 1 point Student's assignment one program detects an unterminated C-style block comment then outputs the error message "ERROR: Program contains C-style, unterminated comment on line 7".	Satisfactory 0.75 points Student's assignment one program outputs a syntax error but the line number where the error occurred is incorrect OR the line number is not identified.	Below Expectation 0 points Student's assignment one program does not detect a syntax error or fails to output a syntax error message. This may be because student's assignment one program failed to compile or was an incomplete solution.	1 point
Total points: 10