19 lines
407 B
Markdown
19 lines
407 B
Markdown
κατα-morphism: Type work
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------------------------
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<pre class="haskell"><code>
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data StrF a = Cons Char a | Nil
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data Str = StrF Str
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-- generalize the construction of Str to other datatype
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-- Mu :: type fixed point
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data Mu f = InF { outF :: f (Mu f) }
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data Str = Mu StrF
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-- Example
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foo=InF { outF = Cons 'f'
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(InF { outF = Cons 'o'
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(InF { outF = Cons 'o'
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(InF { outF = Nil })})})}</code></pre>
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