Re: [Haskell-cafe] Why is $ right associative instead ofleftassociative?

Quoting Paul Hudak :

...

Actually, one of the main reasons that we chose (:) is that that's what Miranda used. So, at the time at least, it was not entirely clear what the "de facto universal inter-language standard" was.

Phil Wadler argued for the ML convention at the time, and wrote a document containing a fair amount of sample code to illustrate what it would look like. We noticed something surprising: instead of (x:xs) and the like, Phil had consistently written (x :: xs) -- note the extra spaces. Somehow, using the longer operator name led him to feel spaces were needed around it. That in turn made his lines longer, encouraged him to split definitions across lines, and so on. When I read the thing, I realised after a while that I was skipping all the code fragments -- because they just looked too big and complicated to take in during a quick reading. It was at least partly that experience that convinced us that using :: for cons would impose a small cost, but a real one, on readability. It may seem trivial, but the sum of many such decisions is significant. The story does illustrate the importance of actually trying out syntactic ideas and seeing how they play--one can be surprised by the result.

...

I don't think Haskell Prime should be about changing the look and feel of the language.

It's about consolidating the most important extensions into the standard, isn't it? Changes that break existing code should be very, very well motivated--if porting code to Haskell Prime is too difficult, people just won't do it. John