I'm trying to understand how generics are instantiated; I figured they would
let me separate the generic declaration with a specified implementation in a
different module, but it seems they don't work that way in practice. I'm trying
to build an MCTS library that doesn't rely on specific details of the data
structures and algorithms being used, for example:
Consider `a.nim`, which has a generic `dostuff` method that relies on an
algorithm specified elsewhere:
# a.nim
proc impl*[T](x: T): string =
quit "bug: override me"
proc dostuff*[T](x: T) =
echo "Calling: ", impl(x)
Run
The actual implementation of `impl` is in `main.nim`:
# main.nim
import a
type Foo = object
proc impl*(x: Foo): string =
return "object: Foo()"
dostuff(Foo())
Run
This doesn't work, I expected "Calling: object: Foo()" but the override
resolution instead uses the generic definition.
Functions like `$` work this way seamlessly. I can have one module define a
`proc `$`*(x: Foo)` and another module that doesn't require it can call `$` on
the object, so I don't understand why this works
