Difference between revisions of "Talk:Graham Scan Implementation"
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(New page: Should "then x: scan (z:xs)" be "then scan (x:z:xs)" in case there are two tight turns in a row?) |
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| + | == Use foldr to simplify buttonLeft == |
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| − | Should "then x: scan (z:xs)" be "then scan (x:z:xs)" in case there are two tight turns in a row? |
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| + | |||
| + | The buttonLeft function can be simplified using foldr like so: |
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| + | <haskell> |
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| + | buttonLeft :: [Pt] -> Pt |
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| + | buttonLeft = folrd minY (Pt (1/0, 1/0)) where |
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| + | minY (Pt (ax, ay)) (Pt (bx, by)) |
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| + | | ay > by = Pt (bx, by) |
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| + | | ay < by = Pt (ax, ay) |
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| + | | ax < bx = Pt (ax, ay) |
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| + | | otherwise = Pt (bx, by) |
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| + | </haskell> |
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Latest revision as of 06:29, 1 September 2014
Use foldr to simplify buttonLeft
The buttonLeft function can be simplified using foldr like so:
buttonLeft :: [Pt] -> Pt
buttonLeft = folrd minY (Pt (1/0, 1/0)) where
minY (Pt (ax, ay)) (Pt (bx, by))
| ay > by = Pt (bx, by)
| ay < by = Pt (ax, ay)
| ax < bx = Pt (ax, ay)
| otherwise = Pt (bx, by)