The Hardest Program I've Ever Written (2015)

There seem to be a lot of posts that attempt to cast seemingly mundane things through an “ethical” lens and I often wonder what the authors of them must be like in real life.

It's certainly an interesting take.

Regarding the second one, a formatter shouldn’t be changing the AST. At most inserting parentheses/braces/semicolons for clarity, which doesn’t change the AST structurally (or, depending on one‘s definition of “AST”, doesn’t change it at all).

> * They don't factor out an expression into a separate variable.

* They implicitly enable people to write deeply nested code that lacks such factoring, without feeling like anything has gone wrong.

> They destroy `git blame`

How is this a problem with auto formatters? This is completely on the person/team, not the tool. Even if the repo doesn’t enforce on pre-commit or something, don’t most formatters have the option to only format lines you’ve actually changed?

> * They don't factor out an expression into a separate variable.

That's...not formatting, and there's probably no good deterministic rule for when to do that, anyhow.

If I didn't want opinions, I'd join a cult.

The bike shedding is optional once one accepts that code written by someone else might look a bit different from ones own. _Some_ conventions are beneficial, and one might discuss those, but one does not have to have complete uniformity.

Bike shedding for weeks might happen and is not helpful. On the other side of this argument there are not-so-very-pleasant things as well. A: We follow this-and-this coding convention and we do not like wasting time on discussing it so we follow it to the letter. B: I don't like this small thing that I would like to write differently. A: We follow this-and-this coding convention and we do not like wasting time on discussing it so we follow it to the letter. B: You actually don't follow this-and-this coding convention because you are not following this-and-that rule. A: Yes, that is a change that I liked.

One can easily end up with a very old coding convention that only the oldest developer likes so the oldest developer can now be dictator over everybody else.

The one they invented to justify hating coding standards.

The human might use a carefully selected mix of tabs and spaces to output a picture. And formatter will destroy it, thus destroying artist expression.

Compare:

    #define/**/Q(x,y)r;char*q/*                         */=y#x","#y")",*p,x=*p%67;}
      /*-IOCCC2020-*/#include/*                         */<stdio.h>/*-BBQlock--*/
        int(y),x,i,k,Q(s[9<<9/*           12            */];float(f)[3];void(Z)
          (){*f=r<0?r:-r;f[1]/*      11         1       */=42.5;f[2]=22.5;for
           (k=0;++k<39;*f/=(k/*   10               2    */%2?k:-k)*6875.5/i)
            y=f[1+k%2]+=*f;k=/*                         */f[2];p=s+k/2*86+y
             ;}int(main)(){p=/*  9         o-------> 3  */s;for(;i<1978;*q
              >32?k=i++/86-11/*           /             */,y=(750>r*r+k*k
              *4)*4+y/2,*p++=/*    8     L         4    */r<44?y?"+0X+0X"
               "+!"[y]-1:*q++/*       7         5       */:10:*q++)r=-41
               +i%86;r=20;for/*            6            */(x=13;(i=3600*
               --x);*p++="XR"/*                         */"MOQSUWAY"[x%+
               10]-9,*p+=x/10/*                         */*41)Z();sscanf
               (__TIME__,"%d"/*  \       /    -------+  */":%d:%d",&k,&x
              ,&i);r=10;for(i/*   \     /     ------ |  */+=(k*60+x)*60;r
              +18;*p=k%2?*p%2/*    \   /      ------ |  */?59:44:*p>39?59
             :39,i=r--?i:i%(+/*     \ /       ------ |  */3600)*12)Z();for
            (p=s;*p;putchar(k/*      X        ------ |  */%2&&k<14?q="End",
           printf("%c%c",224|/*   __/ \__         |  |  */(21554>>k&3),"gCS"
          "gGMX"[k/2]+65),"E"/*  /  \ /  \        |  |  */"Gh_BrG"[k/2]+64:*p
        ),++p)k,"#define/**/"/*  \__/ \__/        +--+  */"Q(x,y)r;cha""r*q=y#"
      "x\",\"#y\")\",*p,x=*p"/*                         */"%67;}/*-IOCCC2020-*/#"
    "include<stdio.h>/*-BBQl"/*                         */"ock--*/int(y),x,i,k,Q(")

and clang-formatted version:

    #define /**/ Q(x, y)                                                           \
      r;                                                                           \
      char *q /*                         */ = y #x "," #y ")", *p, x = *p % 67;    \
      }
    /*-IOCCC2020-*/ #include /*                         */<stdio.h> /*-BBQlock--*/
            int(y),x,i,k,Q(s[9<<9/*           12            */];float(f)[3];void(Z)
              (){
      *f = r < 0 ? r : -r;
      f[1] /*      11         1       */ = 42.5;
      f[2] = 22.5;
      for (k = 0; ++k < 39;
           *f /= (k /*   10               2    */ % 2 ? k : -k) * 6875.5 / i)
        y = f[1 + k % 2] += *f;
      k = /*                         */ f[2];
      p = s + k / 2 * 86 + y;}int(main)(){
      p = /*  9         o-------> 3  */ s;
      for (; i < 1978; *q > 32 ? k = i++ / 86 - 11 /*           /             */,
                                 y = (750 > r * r + k * k * 4) * 4 + y / 2,
                                 *p++ = /*    8     L         4    */ r < 44
                                            ? y ? "+0X+0X"
                                                  "+!"[y] -
                                                      1
                                                : *q++ /*       7         5       */
                                            : 10
                               : *q++)
        r = -41 + i % 86;
      r = 20;for/*            6            */(x=13;(i=3600*
                   --x);*p++="XR"/*                         */"MOQSUWAY"[x%+
                   10]-9,*p+=x/10/*                         */*41)
        Z();
      sscanf(__TIME__, "%d" /*  \       /    -------+  */ ":%d:%d", &k, &x, &i);
      r = 10;
      for (i /*   \     /     ------ |  */ += (k * 60 + x) * 60; r + 18;
           *p = k % 2     ? *p % 2 /*    \   /      ------ |  */ ? 59 : 44
                : *p > 39 ? 59
                          : 39,
           i = r-- ? i : i % (+/*     \ /       ------ |  */ 3600) * 12)
        Z();
      for (p = s; *p;
           putchar(k /*      X        ------ |  */ % 2 &&k < 14
                   ? q = "End",
                     printf("%c%c",
                            224 | /*   __/ \__         |  |  */ (21554 >> k & 3),
                            "gCS"
                            "gGMX"[k / 2] +
                                65),
                     "E" /*  /  \ /  \        |  |  */ "Gh_BrG"[k / 2] + 64 : *p),
          ++p)k,"#define/**/"/*  \__/ \__/        +--+  */"Q(x,y)r;cha""r*q=y#"
          "x\",\"#y\")\",*p,x=*p"/*                         */"%67;}/*-IOCCC2020-*/#"
        "include<stdio.h>/*-BBQl"/*                         */"ock--*/int(y),x,i,k,Q(")

The beauty is gone!

Awesome. From curiosity: is Prince's core still written in Mercury? (Looked at old comments.)

Normally when we are nearly there we say its 95% done and only 95% of the work remains. If your feeling is you are half done I suspect more than 50% of the work remains!

What I know having done a lot in this space is we aren't close!

Again, I don't entirely disagree. Some choices are entirely stylistic: single vs double quotes for strings. Tabs vs spaces. Indentation width. Trailing commas. Those (and others) encode literally 0 meaning, and any time discussing those is time wasted, so they should be auto formatted away.

But some things are not like that. Two statements being right against each other, or having an empty line between them, encodes information.

In a big function call with many arguments, where do you add line breaks between arguments? That can convey information as well. As the posted link says, those are some of the most difficult scenarios for a formatter to try to deal with, and my point is that I think it's not worth the effort.

Nope, just some internal facing code. The challenges boiled down to tracking what parts of the data got successfully sent to which recipients and how to get proof the data were transmitted correctly

I wish I would have found a 3rd party tool to do all this, but I never did

Lots of things are baked into that 95% number. Sometimes the power would go out. Data recipients were careless about checking whether their computers were powered on and had a static IP assigned, but I’d certainly hear about it if they didn’t get their data. Network engineers would futz with settings and do poorly announced infrastructure upgrades. Rather than try to fix all these issues, I just wrote the code assuming we were working from a 3rd world country.