20 lines
777 B
Plaintext
20 lines
777 B
Plaintext
-- The Identity monad is very simple - it wraps a value, and then when bind is called it applies that value
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-- to the function, and then the result is the new Identity. To get at the value, use runIdentity.
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-- Since we're dynamically typed and we don't have subtyping, we use a pair to identify Identities.
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--
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-- This probably doesn't serve a purpose right now, except to show off monads.
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return(x) -> ("identity", x). -- wrap a value
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bind(("identity", x), f) -> f(x). -- apply a value
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runIdentity(("identity", x)) -> x. -- unwrap a value
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-- equivalent to 10 * 4 + 2, but in monadic form (yay!)
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forty_two = bind(return(10), \x ->
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bind(return(x*4), \y ->
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return(y + 2)
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)
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).
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-- print the representation and the actual value
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print(forty_two).
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print(runIdentity(forty_two)). |