On Mon, Feb 04, 2013 at 12:44:53AM +0000, Ben Millwood wrote:
I have two proposals, I suppose: - make bang patterns operate only on variables and wildcards - make bang patterns in let altogether invalid
Looking at this again made me realise that, as well as !_ and !varid lexemes, we could also alter the decl production so that we get decl -> ... | pat rhs -- existing lazy binding production | '!' pat rhs -- new strict binding production That means that let !(x, y) = e in ... would still be valid, with the ! not actually being parsed as part of the pattern, but would parse instead as a strict binding. It would be a little ugly under the hood, as let !x = e in ... would parse as a lazy binding, although we'd want to treat it as a strict binding anyway. Thanks Ian