• @Blue_Morpho
    link
    714 days ago

    You answered your own question. Strings with length are better than null terminated. It is a mistake in the original C language library and probably a hack because the pdp11 used asciz format.

    • @[email protected]
      link
      fedilink
      214 days ago

      Lower performance though. At each iteration through the string you need to compare the length with a counter, which if you want strings longer than 255 characters will have to be multibyte. With NTS you don’t need the counter or the multibyte comparison, strings can be indefinitely long, and you only need to check if the byte you just looked at is zero, which most CPUs do for free so you just use a branch-if-[not-]zero instruction.

      The terminating null also gives you a fairly obvious visual clue where the end of the string is when you’re debugging with a memory dump. Can you tell where the end of this string is: “ABCDEFGH”? What about now: “ABCD\0EFGH”?

      • @Blue_Morpho
        link
        114 days ago

        It’s lower performance in the one situation of iterating on an 8bit ASCII string for programs written 30 years ago but faster in more common uses. Multibyte doesn’t matter when everything is 64 bit. A 64 bit length counter is long enough for everything but the most edgy of edge cases. You take a performance hit if you aren’t aligned.

        Can you tell where the end of this string is: “ABCDEFGH”? What about now: “ABCD\0EFGH”?

        No because unicode and binary formats means a string can contain anything.