73107a083c
## Summary
Adds type inference for list/dict/set comprehensions, including
bidirectional inference:
```py
reveal_type({k: v for k, v in [("a", 1), ("b", 2)]}) # dict[Unknown | str, Unknown | int]
squares: list[int | None] = [x for x in range(10)]
reveal_type(squares) # list[int | None]
```
## Ecosystem impact
I did spot check the changes and most of them seem like known
limitations or true positives. Without proper bidirectional inference,
we saw a lot of false positives.
## Test Plan
New Markdown tests
974 B
974 B
Dictionaries
Empty dictionary
reveal_type({}) # revealed: dict[Unknown, Unknown]
Basic dict
reveal_type({1: 1, 2: 1}) # revealed: dict[Unknown | int, Unknown | int]
Dict of tuples
reveal_type({1: (1, 2), 2: (3, 4)}) # revealed: dict[Unknown | int, Unknown | tuple[int, int]]
Unpacked dict
a = {"a": 1, "b": 2}
b = {"c": 3, "d": 4}
d = {**a, **b}
reveal_type(d) # revealed: dict[Unknown | str, Unknown | int]
Dict of functions
def a(_: int) -> int:
return 0
def b(_: int) -> int:
return 1
x = {1: a, 2: b}
reveal_type(x) # revealed: dict[Unknown | int, Unknown | ((_: int) -> int)]
Mixed dict
# revealed: dict[Unknown | str, Unknown | int | tuple[int, int] | tuple[int, int, int]]
reveal_type({"a": 1, "b": (1, 2), "c": (1, 2, 3)})
Dict comprehensions
# revealed: dict[int | Unknown, int | Unknown]
reveal_type({x: y for x, y in enumerate(range(42))})