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Fixed a couple of typos in the documentation.

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Eric Traut 2022-12-21 10:47:28 -07:00
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@ -334,12 +334,12 @@ def func(a: AnyStr, b: T):
return a + b # Mypy reports 4 errors
```
Pyright cannot use the multi-pass technique as mypy in this case. It needs to produce a single type for any given identifier to support language server features. Pyright instead uses a mechanism called [conditional types](https://github.com/microsoft/pyright/blob/main/docs/type-concepts.md#constrained-type-variables-and-conditional-types). This approach allows pyright to handle some constrained TypeVar use cases that mypy cannot, but there are conversely other use cases that mypy can handle and pyright cannot.
Pyright cannot use the same multi-pass technique as mypy in this case. It needs to produce a single type for any given identifier to support language server features. Pyright instead uses a mechanism called [conditional types](https://github.com/microsoft/pyright/blob/main/docs/type-concepts.md#constrained-type-variables-and-conditional-types). This approach allows pyright to handle some constrained TypeVar use cases that mypy cannot, but there are conversely other use cases that mypy can handle and pyright cannot.
## “Unknown” Type and Strict Mode
Pyright differentiates between explicit and implicit forms of `Any`. The implicit form is referred to as [`Unknown`]https://github.com/microsoft/pyright/blob/main/docs/type-inference.md#unknown-type. For example, if a parameter is annotated as `list[Any]`, that is a use of an explicit `Any`, but if a parameter is annotated as `list`, that is an implicit `Any`, so pyright refers to this type as `list[Unknown]`. Pyright implements several checks that are enabled in “strict” type-checking modes that report the use of an `Unknown` type. Such uses can mask type errors.
Pyright differentiates between explicit and implicit forms of `Any`. The implicit form is referred to as [`Unknown`](https://github.com/microsoft/pyright/blob/main/docs/type-inference.md#unknown-type). For example, if a parameter is annotated as `list[Any]`, that is a use of an explicit `Any`, but if a parameter is annotated as `list`, that is an implicit `Any`, so pyright refers to this type as `list[Unknown]`. Pyright implements several checks that are enabled in “strict” type-checking modes that report the use of an `Unknown` type. Such uses can mask type errors.
Mypy does not track the difference between explicit and implicit `Any` types, but it supports various checks that report the use of values whose type is `Any`: `--warn-return-any` and `--disallow-any-*`. For details, refer to [this documentation](https://mypy.readthedocs.io/en/stable/command_line.html#disallow-dynamic-typing).