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0 pointseru9y ago0 comments

What's the difference between multiple return values and returning a tuple?

(Apart from that languages with multiple return values tend to have some special syntax for binding only the first few members of the returned tuple?)

0 comments

dllthomas9y ago

Apart from what you mention, it's often not possible to pass along all of the multiple return values as a single value.

harveywi9y ago

The difference, in terms of type theory, is that a tuple is a product type [1] but a type representing multiple possible return values (to represent different outcomes) would be encoded using a sum type [2].

[1] https://en.wikipedia.org/wiki/Product_type

[2] https://en.wikipedia.org/wiki/Tagged_union

eruOP9y ago

I don't think eg Go uses a sum type:

https://gobyexample.com/multiple-return-values

Typically they use product types to simulate sum types.

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