Make readFields report if brace syntax is used.

[phadej]

We can use brace syntax to delimit sections and fields in .cabal files. This is e.g. used in changelogs.

However it's somewhat of an obscure feature, I cannot find any examples in documentation using it for example.

It would be useful if readFields reported if braces are used or not. E.g. cabal check (-like tools) could say "don't do that".

[geekosaur]

Are you proposing to remove it? I'm pretty sure I've seen it in the wild, so while obscure it's not completely unknown. (It initially surprised me whne I saw it, but in more of a "oh, they thought of that" fashion.)

[phadej]

Are you proposing to remove it?

No. Just make a way to detect if it's used. See #9099

[phadej]

For curious:

161638 Total files on Hackage at the moment of writing
    18 LexWarningNBSP
     5 LexWarningBOM
  3985 LexWarningTab
  1962 LexInconsistentIndentation
  4223 LexBraces

Braces are slightly more popular than tabs. (And inconsistent indentation was surprisingly common, in 1% of all content).

[ulysses4ever]

I don't see a reason to introduce such a warning. Also, if someone starts seeing the warning it's just some unnecessary churn for them.

[geekosaur]

Same, I'm confused by it being a warning if it's not on the chopping block or at least disrecommended.

[phadej]

I don't see a reason to introduce such a warning. Also, if someone starts seeing the warning it's just some unnecessary churn for them.

The warning is not seen by users of cabal-install.

I want Cabal-syntax parser to tell me whether brace syntax was used. The warning is one way to do that. It would be possible to amend Fields to include that too, but that change would be more intrusive.

This is solely a feature request to Cabal-syntax, it should be a library catering for various user needs dealing with .cabal files, not only a building block of cabal-install. Please keep that in mind.

[ffaf1]

The warning is not seen by users of cabal-install.

It is in your proposal, isn't it?

E.g. cabal check (-like tools) could say "don't do that".

Not knowing much about the parser, I have no opinion.

[phadej]

@ffaf1

It is in your proposal, isn't it?

It isn't.

See https://github.com/phadej/cabal/blob/e3721a22466bd3ad8a30b7ca1ca00d0a08948075/Cabal-syntax/src/Distribution/Fields/LexerMonad.hs#L97-LL99

[phadej]

Ping.