@Kha Could you please take a look at this repro?
When I use the compiler,
```
./run.sh usizeBug.lean
```
I get the expected answer: `2`.
When I use the interpreter,
```
../../bin/lean --run usizeBug.lean
```
I get `1`. I found the problem today, and managed to isolate the
problem to this small repro.
Apparently CMake reverted auto-closing stdin for ctest in a recent release because people relied on the old behavior...
Perhaps we should add this to all test scripts instead, but this CI fix is easier
@Kha @dselsam:
This hack was preventing us from making `Expr` a "real" Lean type.
This was bad for a few reasons:
- It was hard to extend/modify `Expr` in Lean since we would also have
to modify the C++ code that creates the `Expr` objects with the hidden
fields.
- `Expr.lam` and `Expr.forallE` were not following the Lean layout
standard where we sort fields by size. @Kha: recall we used that to
avoid a UB. The issue with `Expr.lam` and `Expr.forallE` is that they
have a "visible" field (`BinderInfo`), which is smaller than
hidden fields such as hash code.
- `Expr.fvar` had only one field at `Expr.lean,` but four behind the
scenes.
I added a new constructor `Local` that is only accessible from C++.
It is only used in legacy code we inherited from Lean2.
We will eventually delete it.
This refactoring was quite painful since many parts of the codebase
were mixing the new `Expr.fvar` with the old `Expr.local`.
I doubt I would be able to do it without the new staging framework
@Kha built.
BTW, some of the patches are horrible. I didn't care much since we
are going to deleted the super ugly files. That being said,
you should expect new weird bevaior due to `Expr.fvar` vs `Expr.local`.
Next step: use the new `ExprCachedData` to make all `Expr` hidden visibles
accessible from Lean.
checkpoint
Motivation: ensure the correct type `IRType` is inferred for definitions
such as
```
def f (n : UInt32) : UInt32 :=
if n == 0 then panic! "foo"
else n+1
```
