Add `getArgs :: IO [OsString]`

[tbidne]

Motivated specifically by pcapriotti/optparse-applicative#491 (comment), though of course said function is generally useful and should exist somewhere, independent of optparse.

If implementing here still seems like the right idea, I am happy to take a crack at it. Thankfully the platform specific versions already exist here and here, so it looks like all that has to be done here is shimming it.

Looking at the existing structure, I am guessing we'd want something like:

-- System.Environment.OsString
getArgs :: IO [OsString]

-- System.Environment.PlatformPath
getArgs :: IO [PlatformPath]

[hasufell]

I'm wondering if this doesn't rather belong in the process package.

It's true process has zero OsPath support right now, but maybe we can start small.

[tbidne]

Thanks for mentioning process. I have also wanted process to acquire OsString compat, and I was not aware of the dedicated issue: haskell/process#252.

That said, I wonder how to justify getArgs specifically. AFAICT process does not export or use getArgs, so this would be "new" functionality independent of mere OsString compat. Eventually I think you'd want the entire System.Environment module implemented for OsString somewhere, but maybe it's reasonable to add getArgs only to process as a stopgap.

[hasufell]

That said, I wonder how to justify getArgs specifically.

• OsPath cannot be in base
• getArgs would be in the process package if it wasn't in base

[hasufell]

We have to see how the maintainer responds, but we have to make clear that you are not intending to add complete OsPath support. That's a very big task that will take a while.

[tbidne]

haskell/process#338

[hasufell]

haskell/process#339