Commit Graph

4 Commits

Author SHA1 Message Date
David Mak 6dccb343bb Revert "core: Do not keep unification result for function arguments"
This reverts commit f09f3c27a5.
2023-12-18 10:01:23 +08:00
David Mak f09f3c27a5 core: Do not keep unification result for function arguments
For some reason, when unifying a function call parameter with an
argument, subsequent calls to the same function will only accept the
type of the substituted argument.

This affect snippets like:

```
def make1() -> C[Literal[1]]:
    return ...

def make2() -> C[Literal[2]]:
    return ...

def consume(instance: C[Literal[1, 2]]):
    pass

consume(make1())
consume(make2())
```

The last statement will result in a compiler error, as the parameter of
consume is replaced with C[Literal[1]].

We fix this by getting a snapshot before performing unification, and
restoring the snapshot after unification succeeds.
2023-12-16 18:40:48 +08:00
David Mak 457d3b6cd7 core: Refactor generic constants to `Literal`
Better matches the syntax of `typing.Literal`.
2023-12-16 18:40:48 +08:00
David Mak 031e660f18 core: Initial implementation for const generics 2023-12-08 18:02:11 +08:00