Re: [Haskell-cafe] Course-of-value recursion by defining a sequence as a self-referential infinite list

On Sat, Feb 8, 2025 at 7:04 AM Pranshu Sharma via Haskell-Cafe < haskell-cafe@haskell.org> wrote:

Vanessa McHale writes:

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Karczmarczuk’s solution via the Haskell prelude:

part = 1 : b 1 where b n = (1 : b (n + 1)) + (replicate n 0 ++ b n)

This is broken code, no?, just 2 reasons I can spot why: - function 'b n' calls 'b n' unconditionally (infite loop)

This definition is meaningful: ones = 1 : ones Now consider onesfun () = 1 : onesfun () The function onesfun calls itself unconditionally. This is broken code, no?

- What is the reutrn type of 'b'? It seems like it returns list, but the return value is in the form 'a + b' , where (+) is instance of num so I don't think prelude contains any ad-hoc definition of (+) that returns list _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.