Re: [Haskell-cafe] Haskell grammar ambiguity

On Wed, Jun 16, 2021 at 09:48:06AM +0200, Sven Panne wrote:

Am Mi., 16. Juni 2021 um 08:47 Uhr schrieb Li-yao Xia :

...

[...] - An ambiguous grammar may be more readable (since there are strictly more choices available), especially if you care more about the AST than the concrete syntax. [...]

IMHO it is exactly the other way around: I consider ambiguous grammars a serious usability bug. [...] The BlockArguments proposal introduced lots of additional ambiguities, and that's the reason why I'm still opposed to it.

[...]

In general, I consider it a very bad idea to give more and more strings a meaning as a program: Some redundancy, like keywords and/or punctuation, is highly useful as a human reader. Remember the old saying "A good language should not make it easy to write correct programs, it should make it hard to write incorrect ones", and BlockArguments was IMHO a step into the wrong direction.

Entirely agreed. The additional difficulty in parsing means that BlockArguments provides *negative* value to me, even if I don't enable it: http://h2.jaguarpaw.co.uk/posts/unhelpful-ghc-error-messages/ Tom