Ask HN: How do you define a junior developer?

Re:Ask HN: How do you define a junior developer? by koenigdavidmj on Thursday September 22, 2016 @01:04PM (#12558293)

Without goto, you get to maintain several copies of your cleanup code, all different:

  int
  insane()
  {
      FILE *a = open("a", "r");
      if (!a) {
          return -1;
      }

      FILE *b = open("b", "r");
      if (!b) {
          fclose(a);
          return -1;
      }

      FILE *c = open("c", "r");
      if (!c) {
          fclose(a);
          fclose(b);
          return -1;
      }

      int rv = (do something with a, b, and c);

      fclose(a);
      fclose(b);
      fclose(c);
      return rv;
  }

Now here's an example where you only need to maintain one copy of your cleanup code:

  int
  reasonable()
  {
      FILE *a = NULL;
      FILE *b = NULL;
      FILE *c = NULL;
      int rv = -1;

      a = open("a", "r");
      if (!a) { goto out; }
      b = open("b", "r");
      if (!b) { goto out; }
      c = open("c", "r");
      if (!c) { goto out; }

      rv = (do something with a, b, and c);

  out:
      if (a) { fclose(a); }
      if (b) { fclose(b); }
      if (c) { fclose(c); }
      return rv;
  }

Avoiding goto gets impossible the second you start doing socket twiddling, or message generation. Yes, languages with context managers (Python's with blocks), RAII (C++ or Rust), or defer (Go) make this easier, but some of us are stuck writing C sometimes.

[ Parent | on HN ]

Re:Ask HN: How do you define a junior developer? by tzs on Thursday September 22, 2016 @01:32PM (#12558539)

Of course in this case you can avoid both the repetition and the goto at the cost of more nesting:

  rv = -1;
  a = open(...);
  if (a) {
    b = open(...);
    if (b) {
      c = open(...);
      if (c) {
        rv = something(a,b,c);
        close(c);
      }
      close(b);
    }
    close(a);
  }
  return rv;

I wonder if there is some sort of program organization analog of Heisenberg's uncertainty principle, where the product of some measure of repetition, some measure of non-structured jumping, and some measure of nesting must be greater than a certain value?

[ Parent | on HN ]