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In Poly ML, how would you write a function that returned "true" if x was of type 'a, and false if it wasn't?

Makarius
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user1775390
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1 Answers1

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I might have misunderstood your question, but it sounds like you have missed the whole point of a statically typed language.

That means you can't call a function with arguments of other types, than what it is declared to. Anything else will be rejected by the interpretor/compiler.

One function that will do what you want is:

> fun foo _ = true
val foo = fn : 'a -> bool
Community
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Jesper.Reenberg
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