[Haskell-cafe] Why is $ right associative
rjmh at cs.chalmers.se
Sun Feb 5 10:13:45 EST 2006
Lennart Augustsson wrote:
> I now think :: for type signatures was a bad mistake.
> I don't use lists very much. They are not the right data structure
> for many things. So : is not as common as :: in my code.
> I checked a small sample of code, about 20000 lines of Haskell.
> It has about 1000 uses of ':' and 2000 of '::'.
Just for interest, I analysed some of my code. Obviously my style is
quite different to yours--my type specialiser of 3,500 lines has 240
conses, and only 22 occurrences of '::'. I seem to be using '::' a bit more
lately, though, which I suspect is due to using classes much more.
I also checked the Agda source code, about 14,000 lines, with
about 500 occurrences of cons and 640 of '::'. I think the only conclusion
one can draw is that style varies.
> In my opinion all the special syntactic sugar for lists should go
> away. I don't think lists are special enough to motivate it.
What, no list comprehensions??
I'd disagree--sequencing is special, and lists represent it directly.
Don't forget, also, that lists are also much more prevalent in beginners'
code--and nice notation for beginners helps get people started on
> But this is not what Haskell' is about. It's supposed to be some
> modest extensions to Haskell. Not designing a new perfect language.
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