On Thu, Apr 15, 2021 at 2:36 PM Hugh Fisher <hugo.fisher@gmail.com> wrote:

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Date: Wed, 14 Apr 2021 09:57:49 +1000 From: Chris Angelico <rosuav@gmail.com> Subject: [Python-Dev] Re: Typing syntax and ecosystem, take 2

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You're advocating an approach that absolutely mandates running the type checker, but then caches the results in an executable file (the JS file built from the TS source). Python already has a caching system - the .pyc files - so if you're importing the same file more than once, the cost of parsing type annotations is pretty much equivalent to the cost of doing it in TypeScript.

Thinking about it, if mypy compiled to .pyc for execution by the Python interpreter most of what I'm complaining about would go away.

The Python interpreter compiles to .pyc for execution by the Python interpreter. Why should MyPy duplicate that work? ChrisA

On Thu, Apr 15, 2021 at 2:36 PM Hugh Fisher <hugo.fisher@gmail.com> wrote:

...

Date: Wed, 14 Apr 2021 09:57:49 +1000 From: Chris Angelico <rosuav@gmail.com> Subject: [Python-Dev] Re: Typing syntax and ecosystem, take 2

...

You're advocating an approach that absolutely mandates running the type checker, but then caches the results in an executable file (the JS file built from the TS source). Python already has a caching system - the .pyc files - so if you're importing the same file more than once, the cost of parsing type annotations is pretty much equivalent to the cost of doing it in TypeScript.

Thinking about it, if mypy compiled to .pyc for execution by the Python interpreter most of what I'm complaining about would go away.

The Python interpreter compiles to .pyc for execution by the Python interpreter. Why should MyPy duplicate that work? ChrisA