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@LightAndLight

LightAndLight/stuff.hs

Created August 13, 2017 22:21
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Prisms?
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stuff.hs
_1st :: Prism' a a' -> Prism' (a, b, c) (a', b, c)
_1st p = prism' (\(a', b, c) -> (p # a', b, c)) (\(a, b, c) -> (,,) <$> a ^? p <*> pure b <*> pure c)
_2nd :: Prism' b b' -> Prism' (a, b, c) (a, b', c)
_2nd p = prism' (\(a, b', c) -> (a, p # b', c)) (\(a, b, c) -> (,,) a <$> b ^? p <*> pure c)
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