Ah, thanks! I tend to feel a bit hazy around "struct"/"union"/"tagged union"/"variant" as I feel the definitions are always language dependent.
On the other hand, product and sum (coproduct) are very well-defined terms which exist far outside any particular language. There's still haziness around choice of category (and, in particular, call-by-value versus call-by-name) but they're an order of magnitude more well-defined. I'd love it if the ADT concept became more widespread and could be easily used as a (low-level) description of more sophisticated typing like struct/variant.
To my ear "union" and "struct" are heavily overloaded since there was never a strict definition of what they should be. Product and Sum (Coproduct) are very well-defined (although, in practice, choice of category leads to some actual haziness especially around CBV/CBN).
In any case, I really appreciate the added detail about how better to use those terms and I'd love if the ideas of sums and products caught on and became a more stable point of communication.
On the other hand, product and sum (coproduct) are very well-defined terms which exist far outside any particular language. There's still haziness around choice of category (and, in particular, call-by-value versus call-by-name) but they're an order of magnitude more well-defined. I'd love it if the ADT concept became more widespread and could be easily used as a (low-level) description of more sophisticated typing like struct/variant.
To my ear "union" and "struct" are heavily overloaded since there was never a strict definition of what they should be. Product and Sum (Coproduct) are very well-defined (although, in practice, choice of category leads to some actual haziness especially around CBV/CBN).
In any case, I really appreciate the added detail about how better to use those terms and I'd love if the ideas of sums and products caught on and became a more stable point of communication.