0360c6b219
## Summary Part of #15382, this PR adds support for calling a variable that's annotated with `typing.Callable`. ## Test Plan Add test cases in a new `call/annotation.md` file.
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typing.Callable
from typing import Callable
def _(c: Callable[[], int]):
reveal_type(c()) # revealed: int
def _(c: Callable[[int, str], int]):
reveal_type(c(1, "a")) # revealed: int
# error: [invalid-argument-type] "Object of type `Literal["a"]` cannot be assigned to parameter 1; expected type `int`"
# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 2; expected type `str`"
reveal_type(c("a", 1)) # revealed: int
The Callable annotation can only be used to describe positional-only parameters.
def _(c: Callable[[int, str], None]):
# error: [unknown-argument] "Argument `a` does not match any known parameter"
# error: [unknown-argument] "Argument `b` does not match any known parameter"
# error: [missing-argument] "No arguments provided for required parameters 1, 2"
reveal_type(c(a=1, b="b")) # revealed: None
If the annotation uses a gradual form (...) for the parameter list, then it can accept any kind of
parameter with any type.
def _(c: Callable[..., int]):
reveal_type(c()) # revealed: int
reveal_type(c(1)) # revealed: int
reveal_type(c(1, "str", False, a=[1, 2], b=(3, 4))) # revealed: int
An invalid Callable form can accept any parameters and will return Unknown.
# error: [invalid-type-form]
def _(c: Callable[42, str]):
reveal_type(c()) # revealed: Unknown