8 lines
365 B
HTML
8 lines
365 B
HTML
<h2 id="κατα-morphism-missing-information-retrieved">κατα-morphism: missing information retrieved</h2>
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<pre><code>type Algebra f a = f a -> a
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instance Functor (StrF a) =
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fmap f (Cons c x) = Cons c (f x)
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fmap _ Nil = Nil</code></pre>
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<pre><code>cata :: Functor f => Algebra f a -> Mu f -> a
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cata f = f . fmap (cata f) . outF</code></pre>
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