Simplify <> for SpaceStatus
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@ -1804,13 +1804,11 @@ prop_checkSpacefulness40= verifyNotTree checkSpacefulness "a=$((x+1)); echo $a"
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data SpaceStatus = SpaceSome | SpaceNone | SpaceEmpty deriving (Eq)
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instance Semigroup SpaceStatus where
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(<>) x y =
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case (x,y) of
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(SpaceNone, SpaceNone) -> SpaceNone
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(SpaceSome, _) -> SpaceSome
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(_, SpaceSome) -> SpaceSome
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(SpaceEmpty, x) -> x
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(x, SpaceEmpty) -> x
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SpaceNone <> SpaceNone = SpaceNone
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SpaceSome <> _ = SpaceSome
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_ <> SpaceSome = SpaceSome
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SpaceEmpty <> x = x
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x <> SpaceEmpty = x
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instance Monoid SpaceStatus where
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mempty = SpaceEmpty
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mappend = (<>)
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