Add labels to json object and list parsing

[FintanH]

Fixes #558

This PR adds better error messages to the parsing of objects and lists.

I'm aware of #559 but this change seems more to the point of giving a better message :)

[bergmark]

Thanks a lot!

It would be really nice to have some tests for this, do you think you have time to add them? Probably in tests/ErrorMessages.hs. I'm sure it works but I can't really tell from the code :-) I was thinking about doing a release later this week so I can add them then otherwise.

Also hlint is nitpicking a bit

Data/Aeson/Parser/Internal.hs:128:11: Suggestion: Move brackets to avoid $
Found:
  (A.satisfy $ \ w -> w == 44 || w == 125) A.<?>
    "expecting ',' or '}'"
Perhaps:
  A.satisfy (\ w -> w == 44 || w == 125) A.<?> "expecting ',' or '}'"
Data/Aeson/Parser/Internal.hs:153:13: Suggestion: Move brackets to avoid $
Found:
  (A.satisfy $ \ w -> w == 44 || w == 93) A.<?>
    "expecting ',' or ']'"
Perhaps:
  A.satisfy (\ w -> w == 44 || w == 93) A.<?> "expecting ',' or ']'"

[FintanH]

Sure I'll try get it done this week 👌

[FintanH]

Should be good now 😄 🤞

[bergmark]

Nice!

The old ghc builds started failing now... looks like we should bump the base compat lower bound to 0.10.1 to get <> in scope.

[FintanH]

The old ghc builds started failing now... looks like we should bump the base compat lower bound to 0.10.1 to get <> in scope.

Since these values are definitely Strings I'll switch it to ++ and it can be backward compat :)

[phadej]

@bergmark bumping base-compat won't get you <>.
See http://hackage.haskell.org/package/base-compat-batteries

I'm neutral on depending on base-compat-batteries, I guess aeson already depends on all of those dependencies.

[bergmark]

Ah, thanks, I misread the base-compat changelog.

I pushed a hopefully final fix, weird that it only affected GHC 7.10.

[bergmark]

re -batteries, i prefer it and would be happy to switch to it.

[FintanH]

@bergmark: This is weird, if you click "Details" to look at the progress on Travis it all looks good but GitHub doesn't seem to be picking this up 🤔

[bergmark]

I'm guessing there was a hiccup in the travis-github integration. No worries.