Generic NewType?

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#3,331 18 comments 35 reactions 0 assignees View on GitHub

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
35/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
tooling

Research direction

Start by reproducing the typing example from the issue and trace how NewType declarations and subscripted type arguments are handled. Define the expected behavior for a generic NewType, including whether SortedList[A] is accepted and type-checked, then add coverage for the example and the reported error.

Written by the indexing model from the issue text.

Description

topic-newtype

I'd like to be able to write code like;

from typing import *
SortedList = NewType('SortedList', List)
A = TypeVar('A')
def my_sorted(items: List[A]) -> SortedList[A]:
    ...

Currently I get error: "SortedList" expects no type arguments, but 1 given

Dominant language
Python
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Avg merge
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Merged PRs (30d)
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