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Comment by _0ffh | Hacker News Reader

Well, after all we've always used CAR and CDR! If it was good enough then, why shouldn't it be good enough now?

Also, the proposed new keywords were on average 50% longer. Just too much typing! With FST and RST they would have stood a chance. HD and TL would have been clear winners!

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That's right, but I would go one step further and have F(irst) and R(est), with obvious composition as follows: (using kruhft's examples from another thread)

    (ff  x) == (caar  x) == (car (car x))
    (rrf x) == (cddar x) == (cdr (cdr (car x)))

I would argue that it's worth sacrificing the 'f' and 'r' symbols for such a common construct.

If not, a common prefix (lacking in HD and TL) could be used:

    (.ff  x) == (caar  x) == (car (car x))
    (.rrf x) == (cddar x) == (cdr (cdr (car x)))

Yes, I realize I'm 55 years late to the party.

And fst and rst allow for composition too:

    caar -> ffst
    cddar -> rrfst

I am disproportionally moved by this elegance.

But that doesn't look as nice.

It would need to have a pronunciation convention before it could catch on.

https://people.eecs.berkeley.edu/~bh/pronounce.scm

Instead of (f)irst/(r)est we could use (h)ead _or_ (f)irst and (r)est. Then the pronunciation is just exactly as it is spelled - https://www.youtube.com/watch?v=spefM2OjKp4

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