-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 10/05/14 14:00, Roelof Wobben wrote:

as I see you changed the main function but I have to make the center function work not change the main function. Your center function takes two tuples, but you give it a tuple of two tuples.

(foo, bar) (fu, baz) is not the same as ((foo, bar), (fu, baz)) Do you see this? The latter is one value, a tuple of tuples. The former, which is what your function expects, is two values. Given the function add x y = x+y You are calling it by "add (1, 2)", when you should be calling it simply by "add 1 2". Hope this helped. - -- Alexander alexander@plaimi.net https://secure.plaimi.net/~alexander -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF4EAREIAAYFAlNuFa0ACgkQRtClrXBQc7WaKgEAqqTU61+Kw/SBbqXMXtW9cY+F Og1VJefDYsBKPxzYf/UA/jmJYe075tinDK7fDGvNSvFu8no/NDx8Sl567lWJ/NFm =r8Ol -----END PGP SIGNATURE-----

Also, in Haskell all functions take only one parameter. If you want a function of two (as in the case of center) there are two ways to achieve that: Make the argument a tuple or make a function with the first argument returning another function taking the second. The latter approach is more common in Haskell. Your definition of center does that. foo x y = x *y is the same as foo x= \y -> x*y and foo = \x -> \y -> x*y On May 10, 2014 2:05 PM, "Corentin Dupont" wrote:

Hi, remember that in Haskell argument application is just a space, not using parenthesis and comma like in some imperative languages. In Java: myFunc (a, b) Is equivalent in Haskell to: myfunc a b so center ((1,2), (3, 4)) is a function applied to only one arguement (a tuple of tuples)

On Sat, May 10, 2014 at 2:00 PM, Roelof Wobben wrote:

...

Mathijs Kwik schreef op 10-5-2014 13:55:

Roelof Wobben writes:

...

Hello,

...

I have to find the center of 2 points as a assigment for a course on fpcomplete. This is no homework because I do a self-study.

So I did this:

center (x1,y1) (x2,y2) = ( ((x1+x2)/2),((y1+y2)/2) ) main = print $ center ((1,2), (3, 4))

should be:

center (x1,y1) (x2,y2) = ( ((x1+x2)/2),((y1+y2)/2) ) main = print $ center (1,2) (3, 4)

oke,

as I see you changed the main function but I have to make the center function work not change the main function.

Roelof

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