[Haskell-cafe] New New newbie question/help
Balu Raman
braman09 at gmail.com
Wed Jun 27 07:25:16 EDT 2007
Hi,
Hope someone can help me, just starting out with SOE.My code :
module Main where
import Graphics.SOE.Gtk
spaceClose :: WIndow -> IO()
spaceClose w = do k <- getKey w
if k == ' ' then closeWindow w
else spaceClose w
equilateralTri :: Window -> Int -> Int -> Int -> IO()
equilateralTri w x y side
= drawInWindow w (withColor Red
(polygon
[(x,y),(a,b),(x,y)]))
where
b = y + side * sin(pi/3)
a = x + side * cos(pi/3)
main =
runGraphics(
do w <- openWindow "Equilateral
Triangle" (400,400)
equilateralTri w 50 300 200
spaceClose w
)
all of the above in file triangle.hs
when I do a :l triangle.h in ghci, I get the following error
triangle.hs:17:36:
No instance for (Floating Int)
arising from use of 'pi' at triangle.hs:17:36-37
Probable fix: add an instance declaration for (Floating Int)
In the first argument of '(/)', namely 'pi'
In the first argument of 'cos', namely '(pi / 3)'
In the second argument of '(*)', namely 'cos (pi/3)'
Failed, modules loaded: none
Can someone help me what's going on to a brand new newbie. All I can
figure out is that some type mismatch between float and int . I tried various
combinations of lets and wheres and I still get the same complaints.
I am just linearly studying SOE
Thanks,
- br
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