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Sometimes you might wish to memoize a function whose input doesn't have the equality and comparison constraints, or maybe the comparison of your given type is just too slow for what you need. To fix this, you simply provide a function which converts the input into something more fitting as an extra parameter.
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// Note that Dictionary lookups are to be much faster than F#'s map and so should // be used when writing library code. let memoizeBy inputToKey f = let cache = Dictionary<_, _>() fun x -> let k = inputToKey x if cache.ContainsKey(k) then cache.[k] else let res = f x cache.[k] <- res res // Example: open System /// a cached version of Type.GetGenericArguments() let cachedGetGenericArguments : Type -> Type[] = memoizeBy (fun t -> t.FullName) (fun t -> t.GetGenericArguments())
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memoize
memoization
functions
utility
memoize
memoization
functions
utility
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