Hi,
On 2012-10-31, at 10:02 AM, Nathan Hüsken
Hey
I have a function which originaly locked like this:
collInfo :: Rect -> Rect -> Maybe CollInfo collInfo (Rect x1 y1 w1 h1) (Rect x2 y2 w2 h2) | x1 + w1 < x2 = Nothing | x1 > x2 + w2 = Nothing | y1 + h1 < y2 = Nothing | y1 > y2 + h2 = Nothing | otherwiese = Just $ makeCollInfo r1 r2
Now I want to refactor it to take Maybe input values
collInfo' :: Maybe Rect -> Maybe Rect -> Maybe CollInfo collInfo' mr1 mr2 = r1 <- mr1 r2 <- mr2 collInfo r1 r2
This is fine, but I would like to write it using only one function. Is there any possibility I can remove collInfo and merge its body into collInfo' and still somehow use the guards (and not a bunch of ifs)?
maybe like: collInfo'' :: Maybe Rect -> Maybe Rect -> Maybe CollInfo collInfo'' (Just r1@(Rect x1 y1 w1 h1)) (Just r2@(Rect x2 y2 w2 h2)) | x1 + w1 < x2 = Nothing | x1 > x2 + w2 = Nothing | y1 + h1 < y2 = Nothing | y1 > y2 + h2 = Nothing | otherwise = Just $ makeCollInfo r1 r2 collInfo'' _ _ = Nothing Cheers, Bob
Thanks, Nathan
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