The switch loop as an expressive device

Consider the switch loop. It's a loop which iterates through the branches of a switch statement, so each iteration does something completely different:

for (int step = 0; step < 3; ++step) {
  switch (step) {
    case 0:
      //do one thing
    case 1:
      //do another thing
    case 2:
      //do something else
  //maybe there's a little bit of common code here

It looks like blatant stupidity, and sometimes it is. An unreflective coder who hears a problem described in a way that sounds sort of like iteration may implement it as a loop, without considering whether that makes any sense.

Sometimes the same thing happens as an innocent result of maintenance. Maybe the loop did make sense once, before the switch grew to dominate its body, and no one has noticed that it no longer does.

But sometimes the switch loop serves an expressive purpose.

What do you do when a function needs to execute part of itself several times with different parameters? You make a local function, of course. But what do you do in a language like C that doesn't have local functions? Or a language like C++ that has them, but only in the awkward form of local classes?

The switch loop is one solution. It allows its body to be executed repeatedly with different parameters, and it avoids duplicating it or removing it from its local context. Loops are C's only portable way to locally express repeated execution, and the switch loop is a way to use one as the best available approximation to a local function.

It's not a good solution. Even in C, it's generally better to use a separate top-level function, even if it takes a lot of parameters and makes no sense outside the calling context. But to a programmer who is reluctant to create new top-level definitions (a rather common, and annoying, aversion), or who simply overvalues locality of expression, I can imagine the switch loop seeming the best of the bad options.

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