sgeop

Ummm Purescript compiles to JS and shares the same runtimes. Both languages have support from popular text editors, and their libraries are compatible and rely on shared access to the common JS ecosystem. In what way is it an apples-to-oranges comparison?

You can already define functions that work on every type that implements Foo, no? I've never coded in go, but I thought that was the whole point of interfaces.

And I don't see how adding generics would solve the problem of being able to add a FooImpl2 to a slice of FooImpls. Java has generics and they don't allow covariant generic collections for this same reason.

What's the difference though? Is this true of interfaces in Java for instance, or does it have to do with the specific implementation of go?

You aren't taking marginal tax rates into account. The tax rate you pay on the incremental 30k is higher than the average tax rate of the first 100k, which makes a significant difference.