Proposal: ArgumentDo

Akio Takano tkn.akio at
Mon Jul 11 01:33:48 UTC 2016

Hi Christian,

On 6 July 2016 at 16:08, C Maeder <chr.maeder at> wrote:
> Hi,
> allowing group A constructs (do, case, ...) and group B constructs (\,
> let, if, ...) as parts of functions application (fexp) without extra
> parentheses looks natural to me. The current state is an artificial and
> unnecessary restriction. Style guides may dictate restrictions, but the
> parser/language should not (without good reasons).
> So +1 for the proposal from me.
> However, I would not distinguish group A and group B constructs in the
> proposed grammar rules. The report already states (for the group B
> constructs):
> "The grammar is ambiguous regarding the extent of lambda abstractions,
> let expressions, and conditionals. The ambiguity is resolved by the
> meta-rule that each of these constructs extends as far to the right as
> possible."

This is a good point, I have updated the wiki page and simplified the
grammar change.

Thank you,

More information about the Glasgow-haskell-users mailing list