length function is confusing

[BurningWitness]

Under Windows length appears to refer to the number of underlying bytes instead of the number of 16-bit codepoints, which is at odds with the rest of the API (and other libraries, e.g. text). numWord, even though it is present in the Short.Word16 module, is not exposed in a cross-platform fashion.

[hasufell]

What function are you referring to exactly?

[hasufell]

You are right: https://hackage.haskell.org/package/os-string-2.0.2.2/docs/System-OsString.html#v:length

All functionss in OsString under windows deal with Word16 boundaries. Length should too.

[hasufell]

Released as https://hackage.haskell.org/package/os-string-2.0.3

[BurningWitness]

Since this directly changes the behavior of the length function, shouldn't this have been a major version bump?

[hasufell]

How so? PVP doesn't specify what to do on behavior changes.

[BurningWitness]

The decision tree on the website has "Did the behavior of any exported functions change?" as one of the questions.

[hasufell]

The decision tree is irrelevant. Please refer to the actual specification text.

For more information see:

• Convention for (optional) annotation of non-inferable major version increments pvp#10
• What is the goal of the PVP? pvp#55

[BurningWitness]

I would simply argue here that since you're obviously changing what length does this is a breaking change (and thus requires a major version bump). I argue for this even knowing that the documentation on the function is quite ambiguous (after all "length" could have always referred to the number of underlying code points and everyone using it could've assumed it to work that way, but never tested under Windows).

This is however not a "please refer to the actual specification text" matter, as the pvp#55 issue you've linked is specifically an ongoing discussion of what the spirit of the PVP is. As such there is no agreement on the matter and whether or not to consider the change in question breaking is currently merely maintainer preference.

[hasufell]

Thanks for your input.