I would appreciate it if someone explained to me what the last two sets of letters are, plus Snedecor. Please don't spoil it for others though
The "Let overwrite, let override" thing is a reference to this and this (see also). (And this, not the code, is what Sagebrysh is saying was enlightening.)
The Lisp code (more specifically, Scheme code) doesn't altogether make sense, and I suspect (1) was posted mostly because "let" is a keyword in Scheme as well as a prominent part of the meme trigger phrase in those books and (2) is as much a comment on the brief thing it's replying to as to the original story. I'll say a few words about it anyway, but what follows is likely to be unsatisfying.
The code uses what's possibly Scheme's most confusing feature, namely call-with-current-continuation (commonly abbreviated call/cc) but unless I'm missing something it does so completely unnecessarily. The code posted is equivalent to this:
(let (overwrite override)
(cond
(meme? (overwrite it))
(else it)))
[EDITED to add: eww, the indentation is messed up and I don't know how to fix it; please imagine that line 2 is indented a little relative to line 1, and lines 3 and 4 a bit further relative to line 2.]
at which point it may be worth mentioning that Scheme is an "expression-oriented" language where every language construct is an expression that has a value. In this case, let establishes a local scope (i.e., a region of the program in which particular names have values assigned to them). The particular form used here isn't strictly legal Scheme, but by analogy with Common Lisp I believe it's intended to create the names overwrite and override and make them both nil or something of the kind.
cond is like "if" in other languages (it's actually a bit more powerful, but it's used here in a way equivalent to an "if"). There had better be, as a result of code not shown here, something called meme? in existence. If it's true (which actually means "any value other than the special one meaning false") then the value of the let-expression will be the result of calling (overwrite it); otherwise it will be the value of it.
So it had also better have been given a value by something not shown here. But, regardless of that, this won't work when meme? is true, because (overwrite it) will fail, because the value of overwrite at this point is nil or undefined or something of the sort.
There may be some further clever idea that I'm missing (perhaps because I haven't actually read the Meme Wars books) and that makes it obvious what eaglejarl meant about the "overarching lambda" (lambda is used to make anonymous functions, which can be bound to variables to make onymous functions; presumably this code is meant to be wrapped up in a lambda, which perhaps gives values to meme? and it; but I have the feeling there's a joke I'm not getting somewhere in this vicinity.
June 2nd, 42 After Fall
Somewhere in the Colorado Mountains
They first caught sight of the man walking a few miles from the compound. At least it looked like a man. Faded jeans, white t-shirt, light jacket, rucksack. White skin, light brown hair. No obvious disabilities. No logos.
They kept him under surveillance as he approached. In other times they might have shot him on sight, but not now. They were painfully aware of the bounds of sustainable genetic diversity, so instead they drove over in a battered van, rifles loaded, industrial earmuffs in place. Once he was on his knees, they sent Javid the Unhearing over to bind and gag him, then bundled him into the van. No reason to risk exposure.
Javid had not always been deaf, but it was an honor. Some must sacrifice for the good of the others, and he was proud to defend the Sanctum at Rogers Ford.
Once back at the complex, they moved the man to a sound-proofed holding room and unbound him. An ancient PC sat on the desk, marked “Imp Association”. The people did not know who the Imp Association were, but they were grateful for it. Perhaps it was a gift from Olson. Praise be to Olson.
With little else to do, the man sat down and read the instructions on the screen. A series of words showed, and he was commanded to select left or right based on various different criteria. It was very confusing.
In a different room, watchers huddled around a tiny screen, looking at a series of numbers.
REP/DEM 0.0012 0.39 0.003
Good. That was a very good start.
FEM/MRA -0.0082 0.28 -0.029
SJW/NRX 0.0065 0.54 0.012
…
Eventually they passed the lines the catechism denoted “purge with fire and never speak thereof”, on to those merely marked as “highly dangerous”.
KO/PEP 0.1781 0.6 0.297
Not as good, but still within the proscribed tolerances. They would run the supplemental.
T_JCB/T_EWD -0.0008 1.2 -0.001
…
The test continued for some time, until eventually the cleric intoned, “The Trial by Fish is complete. He has passed the Snedecor Fish.” The people nodded as if they understood, then proceeded to the next stage.
This was more dangerous. This required a sacrifice.
She was young – just 15 years old. Fresh faced with long blond hair tied back, Sophia had a cute smile: she was perfect for the duty. Her family were told it was an honor to have their daughter selected.
Sophia entered the room, trepidation in her head, a smile on her face. Casually, she offered him a drink, “Hey, sorry you have to go through all this testin’. You must be hot! Would you like a co cuh?” Her relaxed intonation disguised the fact that these words were the proscribed words, passed down through generations, memorized and cherished as a ward against evil. He accepted the bottle of dark liquid and drank, before tossing the recyclable container in the bin.
In the other room, a box marked ‘ECO’ was ticked off.
“Oh, I’m sorry! I made a mistake – that’s pep-see. I’m so sorry!” she gushed in apology. He assured her it was fine.
In the other room, the cleric satisfied himself that the loyalty brand was burning at zero.
She moved on to the next proscribed question, with the ordained level of casualness, “Say, I know this is a silly question, but do you ever get a song stuck in your head?”
“Errr, what?”
“You know, like you just can’t stop singing it to yourself? Yeah?” Of course, she had no idea what this was like. She was alive.
“Ummm, sorry, no.”
She turned and left the room, relief filling her eyes.
…
After three more days of testing, the man was allowed into the compound. Despite the ravages of an evolution with a generational frequency a hundred times that of humanity, he had somehow preserved himself. He was clean of viral memetic payload. He was alive.
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Cross-posted on my blog