Reproducing the behavior

The error was initially reported by @NoamDev here #725 (comment)

Considering this program

# a.bend
from b import *

type MyType:
  A {data: u24}
  B {data: u24}

# b.bend
from a import *

Foo: MyType -> MyType
(Foo (MyType/A a)) = (MyType/A a)
(Foo (MyType/B b)) = (MyType/B b)

# main.bend
from a import *
main = "hello world"

> bend run main.bend
Errors:
In b :
In definition 'b/Foo':
  Unbound variable 'a/MyType'.
  Unbound variable 'a/MyType'.

Investigating this a little bit, it seems that the rebind use MyType = a/MyType in import files that import types.

This happens because all imported binds are considered the same for the import system instead of differentiating between functions and types. The logic for renaming type binds only checks local functions and not imported ones.

I think the way to fix this is to change imports::book::apply_import_binds, specifically to consider the correct sources in the loop that inserts binds in the variable adt_imports, but it seems that it'll require a considerable rework of the import bind logic.

System Settings

Bend commit: 9da1f49

Additional context

No response