On Mon, Feb 04, 2013 at 10:37:44PM +0000, Simon Peyton-Jones wrote:
I don't have a strong opinion about whether f ! x y ! z = e should mean the same; ie whether the space is significant. I think it's probably more confusing if the space is significant (so its presence or absence makes a difference).
I also don't feel strongly, although I lean the other way: I don't think anyone writes "f ! x" when they mean "f with a strict argument x", and I don't see any particular advantage in allowing it. In fact, I think writing that is less clear than "f !x", so there is an advantage in disallowing it. It also means that existing code that defines a (!) operator in infix style would continue to work, provided it puts whitespace around the !. Thanks Ian