[nickpresta]

Hey Vjeux. What does black mean for the prettier python plugin[1]? I had high hopes to move over all projects to prettier (for JS/Python). Is there going to be any merging between prettier python and black? Do you recommend one over the other?

Thanks

[1] https://github.com/prettier/plugin-python

[vjeux]

I don't know :)

I worked on prettier myself because I wanted to solve formatting for the language I was involved in. It turned out that the prettier infrastructure was actually really good for other languages so we used it for CSS, Markdown, GraphQL... and added support for a plugin system for other people to build printers for their own language. patrick91 (not working at Facebook) is working on a python formatter using the prettier infrastructure.

Independently, ambv (working at Facebook) started black which is written in Python. He's part of the Python core team and the Python infrastructure team at Facebook so it made sense for him to drive adoption of black within Facebook.

One interesting thing I realized is that communities are built around programming languages and it's really hard to influence another community from the outside. So my bet would be that black has the most chance of succeeding within the Python community.

[ballenf]

> One interesting thing I realized is that communities are built around programming languages and it's really hard to influence another community from the outside.

IMO, that point is worthy of a detailed blog post or conference talk, if you would be so inclined. Would love to hear more.

[vjeux]

That's true, I'll consider it, in the meantime here are some thoughts.

When I started working on React Native, I thought that the most difficult thing would be to design a good set of APIs to make it easy to write mobile apps using React that felt good. This turned out to be the "easy part", we started the project wanting to solve this and having lots of good ideas on how to do it.

What turned out to be a lot harder was the fact that we were trying to use JavaScript from within iOS and Android ecosystems.

1) Those at the time were in different repos, how do you synchronize code between them?

2) The three ecosystems use a different set of tools for everything: IDE (xcode, intellij, sublime/atom/code/emacs), package manager (cocoapods, maven, npm), linters (eslint), build (how do you hook up with the play button in xcode?), profilers (can you display stack traces with the two languages calling each other?)...

3) Mixing and matching languages inside of a single project is hard because there are a lot of subtle different semantics (eg: javascript doesn't have int32 or int64). If you have type systems, they are incompatible (flow vs obj-c). So in practice you end up with a lot of boilerplate to talk between the two languages and it's a performance overhead.

There's also a social aspect where you invested so much learning an ecosystem that it becomes part of your identity. So you see someone wanting to bring another language as trying to attack you directly.

My mission since then has been trying to "break down the silos" and trying to build tools that can work with all those languages. It's not been easy :)