Environment

• Millet version: ae4b2f4
• Editor version: n/a
• OS version: Fedora 39

Attestation

To avoid filing duplicate issues, I checked:

• The known issues section of the manual
• The existing issue tracker

Steps to reproduce

Run Millet on the following code:

fun foo x =
  let val a = #a x
  in a
  end
and bar () = foo {a = true}

Expected behavior

No errors.

Actual behavior

MLton and SML/NJ accept the code, but Millet produces the following error:

error[5028]: cannot bind expansive polymorphic expression
  ┌─ /home/paul/src/millet/t.sml:2:15
  │
2 │   let val a = #a x
  │               ^^^^

I think Millet should know that #a x is not an expansive polymorphic expression because hovering over x shows { a : bool }.