Fun with bits and character encodings

Starter code: more-bits-package.tar
Upload via Moodle as: more-bits.tar

Goals

• Practice bit operations (~, |, &, ^, <<, >>) in C
• Dig into the details of the UTF-8 character encoding
• Practice writing your own tests

Rubric

Note that "correctness" in this rubric includes "meets all documented specifications". So, for example, if you don't follow the requirement "to_upper may only use bitwise operations on the chars in s" in the documentation for to_upper, that comes out of your "to_upper correctness" score.

Your assignment

• Implement the five functions documented in the bits.h file in more-bits-package.tar.
• Put your implementations in more-bits.c (a starter version of which is provided in the package).
• Do not change more-bits.h.
• Submit your file(s) as more-bits.tar via Moodle.

The only file you are required to submit is more-bits.c. You may include your own main.c and Makefile (starters of which are included in more-bits-package.tar), but we will use our own main.c and Makefile to do our testing and grading.

A little advice

• Read the function definitions in bits.h carefully. They are there to help you!
• Start with to_lower, to_upper, and middle_bits. These don’t require any understanding of UTF-8, and just involve bit operations.
• For help experimenting with UTF-8, you can use my UTF-8 encoding tool.
• For to_utf8 and from_utf8, start by getting single-byte codepoints to work, then two-byte codepoints, etc. Worry about cleaning up your duplicated code after you have everything working.

Have fun!