You would have done well with this kind of thinking in the mid-80s when you needed to fit code and data into maybe 16k!

As long as you were happy to rewrite it in Z80 or 6502.

Another alternative is arithmetic encoding. For instance, if you only needed to store A-Z and space, you code those as 0-26, then multiply each char by 1, 27, 27^2, 26^3 etc, the add them.

To unpack them, divide by 27 repeatedly, the remainder each time is each character. It's simply covering numbers to base-27.

It wouldn't make much difference from using 5 bits per char for a short run, though, but could be efficient for longer strings, or if encoding a smaller set of characters.

After all.. Why not?

Why shouldn’t I ignore the 100+ cultures whose character set couldn’t fit into this encoding?

Oh god that switch statement. Here, let me come up with something better:

if (pChar >= 'a' && pChar <= 'z') {
  return pChar - 'a' + 10;
} else if (pChar == ' ') {
  return 36;
} else if (pChar == '.'){
  return 37;
}
return 0;

Back in the day those tricks were common. Some PDP-11 OS's supported a "Radix-50" encoding (50 octal = 40 decimal) that packed 3 characters into a 16 bit word (40 codepoints=26 letters, 10 digits, and a few punctuation). So you could have a 6.3 filename in 3 words.

CPU still pulls a 32kb block from RAM...

Interesting idea but type conversion and parsing is much more slower than wasting 1 byte. Nowadays memory is "free" and the main issue is the execution speed.

I'm not sure if this is the right setting for technical discussion, but as a relative elder of computing I'd like to answer the question in the image earnestly. There's a few factors squeezing the practicality out of this for almost all applications: processor architectures (like all of them these days) make operating on packed characters take more operations than 8 bit characters so there's a speed tradeoff (especially considering cache and pipelining). Computers these days are built to handle extremely memory demanding video and 3d workloads and memory usage of text data is basically a blip in comparison. When it comes to actual storage and not in-memory representation, compression algorithms typically perform better than just packing each character into fewer bits. You'd need to be in a pretty specific niche for this technique to come in handy again, for better or for worse

Not useless -- you have a future in tiny, embedded systems.

Oh god, please don't. Just use utf8mb4 like a normal human being, and let the encoding issues finally die out (when microsoft kills code pages). If space is of consideration, just use compression, like gz or something.

You could save 0.64 bit per char more if you actually treated you output as a binary number (using 6 bits per char) and didn't go through the intermediary string (implicitly using base 100 at 6.64 bits per char).
This would also make your life easier by allowing bit manipulation to slice/move parts and reducing work for the processor because base 100 means integer divisions, and base 64 means bit shifts. If you want to go down the road of a "complicated" base use base 38 and get similar drawbacks as now, except only 5.25 bits per char.

I do this kind of thing everyday as a firmware engineer :)

It’s all fun and games until the requirement changes and you need to support uppercase letters and digits as well.

Does the efficiency of storage actually matter? Are you working on a constrained system like a microcontroller? Because if you’re working on regular software, supporting Unicode is waaaaaaaaaaay more valuable than 20% smaller text storage.

unsigned int turn_char_to_int(char pChar)
{
    switch(pChar)
    {
    case 'a':
        return 10;
    case 'b':
        return 11;
    case 'c':
        return 12;
    case 'd':
        return 13;
    case 'e':
        return 14;
    case 'f':
        return 15;
    case 'g':
        return 16;
    case 'h':
        return 17;
    case 'i':
        return 18;
    case 'j':
        return 19;
    case 'k':
        return 20;
    case 'l':
        return 21;
    case 'm':
        return 22;
    case 'n':
        return 23;
    case 'o':
        return 24;
    case 'p':
        return 25;
    case 'q':
        return 26;
    case 'r':
        return 27;
    case 's':
        return 28;
    case 't':
        return 29;
    case 'u':
        return 30;
    case 'v':
        return 31;
    case 'w':
        return 32;
    case 'x':
        return 33;
    case 'y':
        return 34;
    case 'z':
        return 35;
    case ' ':
        return 36;
    case '.':
        return 37;

    }
}

Are you a monster or just stupid?

dammit yesterday was too long i thought this was a dnd joke at first

We have a binary file that has to maintain compatibility with a 16 bit Power Basic app that hasn't been recompiled since '99 or '00. We have storage for 8 character strings in two ints , and 12 character string in two ints and two shorts.

I was hopping it was somehow badly implemented in python and each char ended up occupying 2Gb

In typical C fashion, there's undefined behavior in turn_char_to_int. xD

Yes I know, the code is probably bad, but I do not care

That's why we love it.

Mostly because compilers do this kind of stuff if you optimize for space, iirc. Not that you should never do it or something, but it kinda looks like premature optimization to me.