Comment by Nevermark

Arrays and structures are functions.

And all three are tuple [input, output] pattern matches, with the special case that in “call/select tuples”, input is always fully defined, with output simply being the consequence of its match.

And with arrays, structures and overloaded functions being unions of tuples to match to. And structure inputs (I.e. fields) being literal inline enumeration values.

And so are generics.

In fact, in functional programming, everything is a pattern match if you consider even enumeration values as a set of comparison functions that return the highly used enumerations true or false, given sibling values.