in reply to "Correct" program style questions
I've never used the POSIX char classes, but my suggestion would be...
1) Somewhere at the beginning of the write up state something like "For regular expressions I will be using [:alpha:] to match alpha-numerical strings, which is generally matched via [a-zA-Z0-9], so on and so forth for each of the char classes
2) Within the first few snippets give a few quick in regards to TIMTOWTDI with references to camels, llamas, and panthers (o my!), but then state that henceforth your code will always be in this form to maintain consistency across the text.
Also I would show the reasoning behind using multiple variables, even though you don't *have* to, so they at least have a feeling of the thought process behind creating the code. I've heard I don't know how many times.. "Oh yeah, well, I can read it, but writing it is still way too beyond me."... Generally if they can follow the why it was used, the how/when will come as a natural extension
P.s: sorry about nesting the first comment in code blocks, but I'm not familiar with HTML, don't really want to be, and I couldn't figure out how to get a literal bracket, which I will now figure out how to do.. :P
/* And the Creator, against his better judgement, wrote man.c */