[abecedarius]

That's a reasonable guess, but a return would work there. I think I did it this way because all the breaks you need in a switch are noisy -- too noisy if you'd like to write one action per line. However, you can mute the noise by lining it up:

        switch (getchar ()) {
            break; case ' ': enter_text ();
            break; case 'f': view = formulas;
            break; case 'h': col = (col == 0 ? 0 : col-1);

which also makes oops-I-forgot-the-break hard to miss. I hadn't thought of that pattern yet. (You could define a macro for "break; case" too; my friend Kragen calls that IF.)

But I mostly stopped coding in C after around this time.

[kragen]

I thought you were the one who suggested the IF and ELSE macros in http://canonical.org/~kragen/sw/aspmisc/actor.c. :)

Interestingly, in http://canonical.org/~kragen/sw/dev3/paperalgo, I haven't yet run into the desire to have more than one `case` in a pattern-matching `switch`. I just added that piece of code from Vicissicalc to the paperalgo page.

[e12e]

The first break is ignored?

[dlp211]

Not exactly. But it does create a no-op default. I've never seen/used this pattern, so I would have to go compile this down into assembly and play with it to give you a more complete answer.

[abecedarius]

Dropped by dead-code elimination. A compiler might conceivably issue a warning that the first break is unreachable, though that's never happened so far.