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author | Joe Zhao <ztuowen@gmail.com> | 2014-08-09 10:58:03 +0800 |
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committer | Joe Zhao <ztuowen@gmail.com> | 2014-08-09 10:58:03 +0800 |
commit | 5bdaa1e4ffe40add10f000ee993e6b500c419a37 (patch) | |
tree | 46a624488ece8d37fa3580422234ed2b4acc6728 /pole.hs | |
parent | 01aa73b269f7ad780233be338affdf3c9288b1ed (diff) | |
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add files from home for previous chapters and sandboxes
Diffstat (limited to 'pole.hs')
-rw-r--r-- | pole.hs | 27 |
1 files changed, 27 insertions, 0 deletions
@@ -0,0 +1,27 @@ +type Birds = Int +type Pole = (Birds, Birds) + +landLeft :: Birds -> Pole -> Maybe Pole +landLeft n (left, right) + | abs((left+n) - right) < 4 = Just (left + n, right) + | otherwise = Nothing + +landRight :: Birds -> Pole -> Maybe Pole +landRight n (left, right) + | abs((right+n) - left) < 4 = Just (left, right + n) + | otherwise = Nothing + +foo = do + x <- Just 3 + y <- Just "!" + Just (show x ++ y) + +routine = do + start <- return (0,0) + first <- landLeft 2 start + second <- landRight 2 first + landLeft 1 second + +wopwop = do + (x:xs) <- Just "" + return x |