Runtime patching unsupported methods

[whitphx]

• time.sleep() -> await asyncio.sleep()

Such auto-conversion is already implemented in #965 for st.write_stream() that converts st.write_stream() to await st.write_stream(), so we can simply extend it.

[whitphx]

Converting lines inside functions (precisely, "code blocks") is difficult because they are undeterministic.

Here is an example where what sleep in foo refers to is dynamically determined at runtime.

def foo():
    sleep(1)

from time import sleep

foo()

sleep = lambda x: None  # no-op

foo()

On the other hand, the scope of the sleep can be determined by parsing the AST by the nearest-enclosing-scope policy. The point is, the nearest-enclosing-scope is determined at build time (so the scope is deterministic), the name resolution is done by the scope at runtime.

Let's see what some existing static analyzers do: Pylance, for example, parses the example above and infers the sleep as sleep: ((secs: float) -> None) | ((x: Any) -> None), a union type.

So, for this issue, it would be a solution to deal with only the case where the inferred name resolution can be determined as a single result. If so, the example above becomes not a target of this auto-conversion.

[whitphx]

• 1021 only implemented AST conversion of time.sleep() -> await asyncio.sleep(), and converting the normal functions is still todo.

• Converting time.sleep() to await asyncio.sleep() can be replaced with patching time.sleep with asyncio.sleep and AST transformation from time.sleep() to await time.sleep(). This makes the AST processing simpler and looks better.