Add fix for placement after multiline pragma

[nini-faroux]

This is in reference to the issue mentioned in #2392 pr.

It adds a fix for the case where LANGUAGE or OPTIONS_GHC pragmas span multiple lines - where previously it was assuming that they were all single line pragmas.

[pepeiborra]

Is this related to #2364 ?

[jneira]

It seems to me that #2364 rewrites the entire logic so not sure how this fix would fit. Regression tests are useful for sure, thanks!

[nini-faroux]

No it doesn't fix that issue, but it was an issue with the previous solutions from the start it seems, where it was always assumed that the OPTIONS_GHC and LANGUAGE pragmas were just one line.

One thing I was wondering about #2364 that I mentioned in the other pr, is whether it makes sense for the user to add an OPTIONS_GHC pragma or shebang later in the file? As in the user guide the OPTIONS_GHC pragma is considered a file header pragma.

https://downloads.haskell.org/~ghc/7.0.3/docs/html/users_guide/pragmas.html

So even if it compiles, would it be considered a user error to place one lower in the file, or is it common for people to do that? If we can assume that the Shebangs, LANGUAGE and OPTIONS_GHC should all be at the top of the file, we could keep the logic based around that, which would negate the need for a parser as far as I can tell.

But if not, maybe the parser would be the better way to go. I said I'd just add a fix for this in the meantime as the parser pr is currently a draft.

[nini-faroux]

thanks @jneira - yes the parser would replace all of this and deals with this scenario too I think.

[nini-faroux]

I'll close this as #2392 pr will deal with this case also.