Add mapMaybe for Trie #16
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Co-authored-by: Restyled.io <commits@restyled.io>
eborden
suggested changes
Dec 1, 2020
eborden
reviewed
Dec 1, 2020
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| mapMaybe :: (a -> Maybe b) -> Trie a -> Maybe (Trie b) | ||
| mapMaybe f (Trie x) = Trie <$> nullToMaybe (Map.mapMaybe (mapMaybe2 f) x) |
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It would be nice to get a quick check invariant for this.
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Good idea- I added one for making sure that we have the same Justs before and after
eborden
approved these changes
Dec 1, 2020
Co-authored-by: Restyled.io <commits@restyled.io>
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I needed a
mapMaybelike function overTrie awhen trying to write a function to union twoTries with some default behavior intext-assetsThis implements
mapMaybebut with a slight wrinkle in that you ultimately must return aMaybe (Trie a)due to the fact thatTrie ashould be non-empty.