the float type is unbound in a simple program

[LuKuangChen]

What version of Static Python are you using?

9965302
2021-07-15

What program did you run?

# float_unbound.py

def f(x: float):
    reveal_type(x)

What happened?

The variable x has type dynamic.

compiler.static.TypedSyntaxError: reveal_type(x): 'dynamic', 'x' has declared type 'dynamic' and local type 'dynamic'

What should have happened?

We expected that the variable x has type float because of the annotation x: float. The function float has a
type and float(1) has the type Exact[float]

[DinoV]

This is currently due to a combination of behaviors. First, we treat a float annotation as float | int because the Python type checkers treat int as being compatible with float. We then treat arguments which are declared as unions as dynamic because we don't support runtime type checking of them, so we can't keep them typed otherwise the compiler could narrow through isinstance checks incorrectly. If we solved the second issue we'd then report this as int | float.

[carljm]

Closing this as a special case of #49