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Deriving is a powerful feature of GHC. With an extension (or Template Haskell) a programmer can safely derive (steal) instances from other data types of the same representation (or arbitrary isomorphic data types). This avoids boilerplate but also allows users to build a vocabulary of derivations and codified Haskell patterns.
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Baldur is an icelandic developer working at Standard Chartered Bank, London. He is active in the Haskell community and a moderator on r/haskell.