RE: Re: [Haskell-cafe] Fractional/negative fixity?

Nicolas Frisby wrote:

Let's remember that if something is broke, it's only _right_ to _fix_ it. I patiently waited for someone else to make that pun.

Understanding the language won't be much harder, but understanding fixity declarations will become a task. Consider:

infixl -1.7521 -- what and why?

As the operator space becomes more dense, negative and fractional fixities are going to become more obfuscated. The negative and fractional fixities will satisfy a number purposes well, but they will also be abused and lead to confusion.

This smells like a wart growing on a wart to me.

All these are valid points. However, given that we can't completely redesign, implement and test a new fixity system in time for Haskell', it makes sense to make a simple change that unambiguously improves the current system, and is no more difficult to implement (in fact, I bet it adds zero lines of code to the compiler). Cheers, Simon

Nick

On 11/7/06, David House wrote:

...

On 07/11/06, Jon Fairbairn wrote:

...

I must say though, that I don't like the reasoning that we can put in fractional fixities because it's a small change. The way to hell is through a series of small steps. If using integers to express fixities is a bit of a hack, switching to rational numbers is a hack on top of a hack.

Well, It's a _conceptually_ simple idea, one that doesn't make understanding the language much harder.

Also, it provides an infinite space for fixities. I think the problem 'binds tighter than X but not as tight as Y', where X and Y are only fixity integer apart is somewhat common, and this would fix it. It would allow for extensibility into the future, where the operator space will only become more dense, and maintaining a complete order with only 10 integers to play will become more and more difficult. Allowing an infinite amount of operators to come between any two operators sounds like a solid design decision to me.

-- -David House, dmhouse@gmail.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe