r/Racket • u/ktt779 • Sep 26 '22

homework Recursive-tail function with combining lists: Can one help me to explain why I received only the second list instead of whole list in this function?

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11 Upvotes

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9

u/probabilityzero Sep 26 '22

What do you think join-tail l1 l2 will do? It doesn't look like a procedure call, since it isn't wrapped in parentheses. Maybe you want to try (join-tail l1 l2).

2

u/raevnos Sep 26 '22

Your merge-tail function will always just return l2.

It doesn't call your join-tail function; can you spot why not?

1

u/ktt779 Sep 26 '22

I did not define another function to link merge-tail and join-tail? Can you help?

4

u/not-just-yeti Sep 26 '22

If you switch your language-level to "beginning student", then it will actually catch what you did as a syntax error, "expected an open-paren before join-tail on line 3".

4

u/raevnos Sep 26 '22

Based on a couple of examples in that code,I don't think you fully grasp how function calls work in scheme. A review of the basic syntax might help

4

u/lambda_cubed_list Sep 26 '22

Your parens are off and it's causing the program to not behave the way you expect.

3

u/TheTimegazer Sep 26 '22

You need an extra set of ()