Help with DrScheme

[Cronox1]

Hi im new to schemce and Im trying out a couple of things.

Im trying to do two different functions

For the first I'm trying to do the reverse of cons so basically I was write a function called revcon that could do this

(revcon '(a b) '(c d))
and give me

(c d a b)

I thought about doing a cons then doing a reverse on it but that didnt work and i was gonna see if any ideas were available for this.

As for my other function I want to make a function that will take a number and an atom will make a copy of the atom however many times of the number given.

So for instance if i called it copy I would have

(copy 4 'd)
and I would get

d d d d

I have tried different things with this but no luck.

If anyone could help me with this I would greatly appreciate it thanks in advance.

[GnuVince]

For your copy function, try this:

(define (copy n elt)
(if (<= n 0)
()
(cons elt (copy (- n 1) elt))))

[Cronox1]

Is elt some special function in scheme or is that something you made up?

[GnuVince]

No, it's short for "element"

[Cronox1]

For element do you mean thats just the atom im excepting so if im taking in hello as the item to print out 3 times its represented by elt

[GnuVince]

It's usual to call the items of a list, the elements. So, you give to your function a number n and an element elt with which you want to make a list.

[Cronox1]

ok many thanks

[jemfinch]

(revcon '(a b) '(c d))
and give me

(c d a b)

(cons '(a b) '(c d)) would give you ((a b) . (c d)), not ((a b) (c d)).

Jeremy

[DrSchemer]

I have a program that might work with this

HELPER FUNCTIONS

(define (hours-schemeing youspendyourlifeatthecomputer)
(= 60))


personality:your-name->your-social-status

(define (personality your-name)
(cond
[(> hours-scheming 100) "YOU ARE A NERD and a Douchbag"]
[(= program-in-scheme your-programming-language) (personality (- yourname 1))]
[else "you have a life"]))