On Sun, Dec 13, 2020 at 01:29:31PM +0100, Zelphir Kaltstahl wrote:
> Hello Taylan!
> 
> I tried your procedure and indeed it seems to work : )
> 
> I think what I had been missing before were 2 things:
> 
> 1. I did not have the (if (null? rest) ...) parts, so I always tried to
> directly make a recursive call, perhaps wrapped into a cons, append or

    "When recurring on a list of atoms, /lat/, ask
    two questions about it: /(null? lat)/ and *else*.
    When recurring on a number, /n/, ask two
    questions about it: /(zero? n)/ and *else*.
    When recurring on a list of S-expressions, /l/,
    ask three question about it: /(null? l)/, /(atom?
    ( car l))/, and *else*."

Daniel P. Friedman and Matthias Felleisen: The Little Schemer [1]
"First Commandment".

Now before this sounds arrogant or something: this is a botch
I'd be very likely to do myself. That's perhaps why this book,
which at first sight looks so harmless, was for me a joy to read.

Cheers

[1] https://pdfs.semanticscholar.org/35d0/d5275a8390c351ce98fbdc2ad37d210ba63b.pdf

 - t