evanrinehart / borax

Borax

B interpreter.

B was developed at Bell Labs by Ken Thompson and Dennis M. Ritchie. The target application was system software for minicomputers.

Supports

• Bitwise complement operator ~
• break; statement performs the equivalent of a goto out of nearest switch or while statement.
• Automatic vector declarations use square brackets to indicate size.
• Vectors declared with size N actually hold N+1 words. The bonus 1 word of space can be ignored or not. In particular vect[N] is not an error.
• Octal numeric constants may include 8s and 9s, i.e. 09 = 011.

Example

main() {
  extrn printf, getchar, time, exit;
  auto timev[2];

  printf("What is my task...*n");
  printf("o - print Hello World*n");
  printf("t - print system time*n");
  printf("x - exit immediately*n");
  printf("> ");

  switch getchar() {
    case 'o':
      printf("Hello World!*n");
      goto done;
    case 't':
      time(timev);
      printf("The system time is (%d,%d)*n", timev[0], timev[1]);
      goto done;
    case 'x':
      printf("As you wish--");
      exit();
      goto done;
  }

  done: printf("End of Program*n");
}

References

• Users' Reference to B (1972) by Ken Thompson
• Bell Laboratories Computing Science Technical Report #8: The Programming Language B (1973) (Brian Kernighan, Steve Johnson)