some work on avoiding partial functions
There are still hundreds of places that use partial functions head, tail, init, and last.
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4 changed files with 45 additions and 14 deletions
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@ -27,6 +27,19 @@ readMaybe s = case reads s of
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((x,_):_) -> Just x
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_ -> Nothing
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{- Like break, but the character matching the condition is not included
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- in the second result list.
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-
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- separate (== ':') "foo:bar" = ("foo", "bar")
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- separate (== ':') "foobar" = ("foo, "")
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-}
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separate :: (a -> Bool) -> [a] -> ([a], [a])
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separate c l = unbreak $ break c l
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where
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unbreak r@(a, b)
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| null b = r
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| otherwise = (a, tail b)
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{- Catches IO errors and returns a Bool -}
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catchBoolIO :: IO Bool -> IO Bool
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catchBoolIO a = catchDefaultIO a False
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